xref: /llvm-project/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (revision 848d3d0d2c45334f090dbf315501ebafe75f4b4d)
1 //===- ARMDisassembler.cpp - Disassembler for ARM/Thumb ISA ---------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "MCTargetDesc/ARMAddressingModes.h"
10 #include "MCTargetDesc/ARMBaseInfo.h"
11 #include "MCTargetDesc/ARMMCTargetDesc.h"
12 #include "TargetInfo/ARMTargetInfo.h"
13 #include "Utils/ARMBaseInfo.h"
14 #include "llvm/MC/MCContext.h"
15 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
16 #include "llvm/MC/MCFixedLenDisassembler.h"
17 #include "llvm/MC/MCInst.h"
18 #include "llvm/MC/MCInstrDesc.h"
19 #include "llvm/MC/MCSubtargetInfo.h"
20 #include "llvm/MC/SubtargetFeature.h"
21 #include "llvm/Support/Compiler.h"
22 #include "llvm/Support/ErrorHandling.h"
23 #include "llvm/Support/MathExtras.h"
24 #include "llvm/Support/TargetRegistry.h"
25 #include "llvm/Support/raw_ostream.h"
26 #include <algorithm>
27 #include <cassert>
28 #include <cstdint>
29 #include <vector>
30 
31 using namespace llvm;
32 
33 #define DEBUG_TYPE "arm-disassembler"
34 
35 using DecodeStatus = MCDisassembler::DecodeStatus;
36 
37 namespace {
38 
39   // Handles the condition code status of instructions in IT blocks
40   class ITStatus
41   {
42     public:
43       // Returns the condition code for instruction in IT block
44       unsigned getITCC() {
45         unsigned CC = ARMCC::AL;
46         if (instrInITBlock())
47           CC = ITStates.back();
48         return CC;
49       }
50 
51       // Advances the IT block state to the next T or E
52       void advanceITState() {
53         ITStates.pop_back();
54       }
55 
56       // Returns true if the current instruction is in an IT block
57       bool instrInITBlock() {
58         return !ITStates.empty();
59       }
60 
61       // Returns true if current instruction is the last instruction in an IT block
62       bool instrLastInITBlock() {
63         return ITStates.size() == 1;
64       }
65 
66       // Called when decoding an IT instruction. Sets the IT state for
67       // the following instructions that for the IT block. Firstcond
68       // corresponds to the field in the IT instruction encoding; Mask
69       // is in the MCOperand format in which 1 means 'else' and 0 'then'.
70       void setITState(char Firstcond, char Mask) {
71         // (3 - the number of trailing zeros) is the number of then / else.
72         unsigned NumTZ = countTrailingZeros<uint8_t>(Mask);
73         unsigned char CCBits = static_cast<unsigned char>(Firstcond & 0xf);
74         assert(NumTZ <= 3 && "Invalid IT mask!");
75         // push condition codes onto the stack the correct order for the pops
76         for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
77           unsigned Else = (Mask >> Pos) & 1;
78           ITStates.push_back(CCBits ^ Else);
79         }
80         ITStates.push_back(CCBits);
81       }
82 
83     private:
84       std::vector<unsigned char> ITStates;
85   };
86 
87 /// ARM disassembler for all ARM platforms.
88 class ARMDisassembler : public MCDisassembler {
89 public:
90   ARMDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx) :
91     MCDisassembler(STI, Ctx) {
92   }
93 
94   ~ARMDisassembler() override = default;
95 
96   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
97                               ArrayRef<uint8_t> Bytes, uint64_t Address,
98                               raw_ostream &VStream,
99                               raw_ostream &CStream) const override;
100 };
101 
102 /// Thumb disassembler for all Thumb platforms.
103 class ThumbDisassembler : public MCDisassembler {
104 public:
105   ThumbDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx) :
106     MCDisassembler(STI, Ctx) {
107   }
108 
109   ~ThumbDisassembler() override = default;
110 
111   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
112                               ArrayRef<uint8_t> Bytes, uint64_t Address,
113                               raw_ostream &VStream,
114                               raw_ostream &CStream) const override;
115 
116 private:
117   mutable ITStatus ITBlock;
118 
119   DecodeStatus AddThumbPredicate(MCInst&) const;
120   void UpdateThumbVFPPredicate(DecodeStatus &, MCInst&) const;
121 };
122 
123 } // end anonymous namespace
124 
125 static bool Check(DecodeStatus &Out, DecodeStatus In) {
126   switch (In) {
127     case MCDisassembler::Success:
128       // Out stays the same.
129       return true;
130     case MCDisassembler::SoftFail:
131       Out = In;
132       return true;
133     case MCDisassembler::Fail:
134       Out = In;
135       return false;
136   }
137   llvm_unreachable("Invalid DecodeStatus!");
138 }
139 
140 // Forward declare these because the autogenerated code will reference them.
141 // Definitions are further down.
142 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
143                                    uint64_t Address, const void *Decoder);
144 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
145                                    uint64_t Address, const void *Decoder);
146 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
147                                    uint64_t Address, const void *Decoder);
148 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
149                                    uint64_t Address, const void *Decoder);
150 static DecodeStatus DecodeGPRnopcRegisterClass(MCInst &Inst,
151                                                unsigned RegNo, uint64_t Address,
152                                                const void *Decoder);
153 static DecodeStatus DecodeGPRwithAPSRRegisterClass(MCInst &Inst,
154                                                unsigned RegNo, uint64_t Address,
155                                                const void *Decoder);
156 static DecodeStatus DecodeGPRwithZRRegisterClass(MCInst &Inst,
157                                                unsigned RegNo, uint64_t Address,
158                                                const void *Decoder);
159 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
160                                    uint64_t Address, const void *Decoder);
161 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
162                                    uint64_t Address, const void *Decoder);
163 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
164                                    uint64_t Address, const void *Decoder);
165 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
166                                    uint64_t Address, const void *Decoder);
167 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
168                                    uint64_t Address, const void *Decoder);
169 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
170                                    uint64_t Address, const void *Decoder);
171 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
172                                    uint64_t Address, const void *Decoder);
173 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
174                                    uint64_t Address, const void *Decoder);
175 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
176                                    uint64_t Address, const void *Decoder);
177 static DecodeStatus DecodeDPR_VFP2RegisterClass(MCInst &Inst,
178                                                 unsigned RegNo,
179                                                 uint64_t Address,
180                                                 const void *Decoder);
181 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
182                                    uint64_t Address, const void *Decoder);
183 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
184                                    uint64_t Address, const void *Decoder);
185 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
186                                unsigned RegNo, uint64_t Address,
187                                const void *Decoder);
188 
189 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
190                                uint64_t Address, const void *Decoder);
191 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
192                                uint64_t Address, const void *Decoder);
193 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
194                                uint64_t Address, const void *Decoder);
195 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
196                                uint64_t Address, const void *Decoder);
197 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
198                                uint64_t Address, const void *Decoder);
199 
200 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Insn,
201                                uint64_t Address, const void *Decoder);
202 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
203                                uint64_t Address, const void *Decoder);
204 static DecodeStatus DecodeAddrMode2IdxInstruction(MCInst &Inst,
205                                                   unsigned Insn,
206                                                   uint64_t Address,
207                                                   const void *Decoder);
208 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Insn,
209                                uint64_t Address, const void *Decoder);
210 static DecodeStatus DecodeAddrMode3Instruction(MCInst &Inst,unsigned Insn,
211                                uint64_t Address, const void *Decoder);
212 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Insn,
213                                uint64_t Address, const void *Decoder);
214 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Insn,
215                                uint64_t Address, const void *Decoder);
216 
217 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst & Inst,
218                                                   unsigned Insn,
219                                                   uint64_t Adddress,
220                                                   const void *Decoder);
221 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
222                                uint64_t Address, const void *Decoder);
223 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
224                                uint64_t Address, const void *Decoder);
225 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
226                                uint64_t Address, const void *Decoder);
227 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
228                                uint64_t Address, const void *Decoder);
229 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
230                                uint64_t Address, const void *Decoder);
231 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
232                                uint64_t Address, const void *Decoder);
233 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
234                                uint64_t Address, const void *Decoder);
235 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
236                                uint64_t Address, const void *Decoder);
237 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
238                                uint64_t Address, const void *Decoder);
239 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
240                                uint64_t Address, const void *Decoder);
241 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
242                                uint64_t Address, const void *Decoder);
243 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
244                                uint64_t Address, const void *Decoder);
245 static DecodeStatus DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
246                                uint64_t Address, const void *Decoder);
247 static DecodeStatus DecodeBranchImmInstruction(MCInst &Inst,unsigned Insn,
248                                uint64_t Address, const void *Decoder);
249 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
250                                uint64_t Address, const void *Decoder);
251 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Val,
252                                uint64_t Address, const void *Decoder);
253 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Val,
254                                uint64_t Address, const void *Decoder);
255 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Val,
256                                uint64_t Address, const void *Decoder);
257 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Val,
258                                uint64_t Address, const void *Decoder);
259 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Val,
260                                uint64_t Address, const void *Decoder);
261 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Val,
262                                uint64_t Address, const void *Decoder);
263 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Val,
264                                uint64_t Address, const void *Decoder);
265 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Val,
266                                uint64_t Address, const void *Decoder);
267 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Val,
268                                uint64_t Address, const void *Decoder);
269 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Val,
270                                uint64_t Address, const void *Decoder);
271 static DecodeStatus DecodeNEONModImmInstruction(MCInst &Inst,unsigned Val,
272                                uint64_t Address, const void *Decoder);
273 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Val,
274                                uint64_t Address, const void *Decoder);
275 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
276                                uint64_t Address, const void *Decoder);
277 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
278                                uint64_t Address, const void *Decoder);
279 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
280                                uint64_t Address, const void *Decoder);
281 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
282                                uint64_t Address, const void *Decoder);
283 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
284                                uint64_t Address, const void *Decoder);
285 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
286                                uint64_t Address, const void *Decoder);
287 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Insn,
288                                uint64_t Address, const void *Decoder);
289 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Insn,
290                                uint64_t Address, const void *Decoder);
291 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Insn,
292                                uint64_t Address, const void *Decoder);
293 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Insn,
294                                uint64_t Address, const void *Decoder);
295 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Insn,
296                                uint64_t Address, const void *Decoder);
297 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
298                                uint64_t Address, const void *Decoder);
299 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
300                                uint64_t Address, const void *Decoder);
301 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
302                                uint64_t Address, const void *Decoder);
303 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
304                                uint64_t Address, const void *Decoder);
305 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
306                                uint64_t Address, const void *Decoder);
307 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
308                                uint64_t Address, const void *Decoder);
309 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
310                                uint64_t Address, const void *Decoder);
311 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
312                                uint64_t Address, const void *Decoder);
313 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
314                                uint64_t Address, const void *Decoder);
315 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
316                                uint64_t Address, const void *Decoder);
317 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
318                                uint64_t Address, const void *Decoder);
319 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
320                                uint64_t Address, const void *Decoder);
321 static DecodeStatus DecodeVST3LN(MCInst &Inst, unsigned Insn,
322                                uint64_t Address, const void *Decoder);
323 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
324                                uint64_t Address, const void *Decoder);
325 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
326                                uint64_t Address, const void *Decoder);
327 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
328                                uint64_t Address, const void *Decoder);
329 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
330                                uint64_t Address, const void *Decoder);
331 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
332                                 uint64_t Address, const void *Decoder);
333 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
334                                 uint64_t Address, const void *Decoder);
335 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
336                                                        unsigned Val,
337                                                        uint64_t Address,
338                                                        const void *Decoder);
339 
340 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
341                                uint64_t Address, const void *Decoder);
342 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
343                                uint64_t Address, const void *Decoder);
344 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
345                                uint64_t Address, const void *Decoder);
346 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
347                                uint64_t Address, const void *Decoder);
348 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
349                                uint64_t Address, const void *Decoder);
350 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
351                                uint64_t Address, const void *Decoder);
352 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
353                                uint64_t Address, const void *Decoder);
354 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
355                                uint64_t Address, const void *Decoder);
356 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
357                                uint64_t Address, const void *Decoder);
358 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Val,
359                                uint64_t Address, const void *Decoder);
360 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
361                                uint64_t Address, const void* Decoder);
362 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
363                                uint64_t Address, const void* Decoder);
364 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
365                                uint64_t Address, const void* Decoder);
366 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
367                                uint64_t Address, const void* Decoder);
368 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
369                                uint64_t Address, const void *Decoder);
370 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val,
371                                uint64_t Address, const void *Decoder);
372 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
373                                uint64_t Address, const void *Decoder);
374 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
375                                            uint64_t Address,
376                                            const void *Decoder);
377 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
378                                uint64_t Address, const void *Decoder);
379 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
380                                uint64_t Address, const void *Decoder);
381 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
382                                uint64_t Address, const void *Decoder);
383 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Val,
384                                uint64_t Address, const void *Decoder);
385 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
386                                 uint64_t Address, const void *Decoder);
387 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
388                                 uint64_t Address, const void *Decoder);
389 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
390                                 uint64_t Address, const void *Decoder);
391 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Insn,
392                                 uint64_t Address, const void *Decoder);
393 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
394                                 uint64_t Address, const void *Decoder);
395 static DecodeStatus DecodeThumbTableBranch(MCInst &Inst, unsigned Val,
396                                 uint64_t Address, const void *Decoder);
397 static DecodeStatus DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Val,
398                                 uint64_t Address, const void *Decoder);
399 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
400                                 uint64_t Address, const void *Decoder);
401 static DecodeStatus DecodeThumbBCCTargetOperand(MCInst &Inst,unsigned Val,
402                                 uint64_t Address, const void *Decoder);
403 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
404                                 uint64_t Address, const void *Decoder);
405 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Val,
406                                 uint64_t Address, const void *Decoder);
407 static DecodeStatus DecodeT2LDRDPreInstruction(MCInst &Inst,unsigned Insn,
408                                uint64_t Address, const void *Decoder);
409 static DecodeStatus DecodeT2STRDPreInstruction(MCInst &Inst,unsigned Insn,
410                                uint64_t Address, const void *Decoder);
411 static DecodeStatus DecodeT2Adr(MCInst &Inst, unsigned Val,
412                                 uint64_t Address, const void *Decoder);
413 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Val,
414                                 uint64_t Address, const void *Decoder);
415 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, unsigned Val,
416                                 uint64_t Address, const void *Decoder);
417 
418 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
419                                 uint64_t Address, const void *Decoder);
420 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
421                                             uint64_t Address, const void *Decoder);
422 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
423                                          uint64_t Address, const void *Decoder);
424 
425 template <bool isSigned, bool isNeg, int size>
426 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned val,
427                                          uint64_t Address, const void *Decoder);
428 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned val,
429                                                uint64_t Address,
430                                                const void *Decoder);
431 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
432                                           uint64_t Address,
433                                           const void *Decoder);
434 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
435                                  const void *Decoder);
436 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
437                                            uint64_t Address,
438                                            const void *Decoder);
439 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
440                                   const void *Decoder);
441 template<bool Writeback>
442 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Insn,
443                                           uint64_t Address,
444                                           const void *Decoder);
445 static DecodeStatus DecodeMVEOverlappingLongShift(MCInst &Inst, unsigned Insn,
446                                                   uint64_t Address,
447                                                   const void *Decoder);
448 #include "ARMGenDisassemblerTables.inc"
449 
450 static MCDisassembler *createARMDisassembler(const Target &T,
451                                              const MCSubtargetInfo &STI,
452                                              MCContext &Ctx) {
453   return new ARMDisassembler(STI, Ctx);
454 }
455 
456 static MCDisassembler *createThumbDisassembler(const Target &T,
457                                                const MCSubtargetInfo &STI,
458                                                MCContext &Ctx) {
459   return new ThumbDisassembler(STI, Ctx);
460 }
461 
462 // Post-decoding checks
463 static DecodeStatus checkDecodedInstruction(MCInst &MI, uint64_t &Size,
464                                             uint64_t Address, raw_ostream &OS,
465                                             raw_ostream &CS,
466                                             uint32_t Insn,
467                                             DecodeStatus Result) {
468   switch (MI.getOpcode()) {
469     case ARM::HVC: {
470       // HVC is undefined if condition = 0xf otherwise upredictable
471       // if condition != 0xe
472       uint32_t Cond = (Insn >> 28) & 0xF;
473       if (Cond == 0xF)
474         return MCDisassembler::Fail;
475       if (Cond != 0xE)
476         return MCDisassembler::SoftFail;
477       return Result;
478     }
479     case ARM::t2ADDri:
480     case ARM::t2ADDri12:
481     case ARM::t2ADDrr:
482     case ARM::t2ADDrs:
483     case ARM::t2SUBri:
484     case ARM::t2SUBri12:
485     case ARM::t2SUBrr:
486     case ARM::t2SUBrs:
487       if (MI.getOperand(0).getReg() == ARM::SP &&
488           MI.getOperand(1).getReg() != ARM::SP)
489         return MCDisassembler::SoftFail;
490       return Result;
491     default: return Result;
492   }
493 }
494 
495 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
496                                              ArrayRef<uint8_t> Bytes,
497                                              uint64_t Address, raw_ostream &OS,
498                                              raw_ostream &CS) const {
499   CommentStream = &CS;
500 
501   assert(!STI.getFeatureBits()[ARM::ModeThumb] &&
502          "Asked to disassemble an ARM instruction but Subtarget is in Thumb "
503          "mode!");
504 
505   // We want to read exactly 4 bytes of data.
506   if (Bytes.size() < 4) {
507     Size = 0;
508     return MCDisassembler::Fail;
509   }
510 
511   // Encoded as a small-endian 32-bit word in the stream.
512   uint32_t Insn =
513       (Bytes[3] << 24) | (Bytes[2] << 16) | (Bytes[1] << 8) | (Bytes[0] << 0);
514 
515   // Calling the auto-generated decoder function.
516   DecodeStatus Result =
517       decodeInstruction(DecoderTableARM32, MI, Insn, Address, this, STI);
518   if (Result != MCDisassembler::Fail) {
519     Size = 4;
520     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn, Result);
521   }
522 
523   struct DecodeTable {
524     const uint8_t *P;
525     bool DecodePred;
526   };
527 
528   const DecodeTable Tables[] = {
529       {DecoderTableVFP32, false},      {DecoderTableVFPV832, false},
530       {DecoderTableNEONData32, true},  {DecoderTableNEONLoadStore32, true},
531       {DecoderTableNEONDup32, true},   {DecoderTablev8NEON32, false},
532       {DecoderTablev8Crypto32, false},
533   };
534 
535   for (auto Table : Tables) {
536     Result = decodeInstruction(Table.P, MI, Insn, Address, this, STI);
537     if (Result != MCDisassembler::Fail) {
538       Size = 4;
539       // Add a fake predicate operand, because we share these instruction
540       // definitions with Thumb2 where these instructions are predicable.
541       if (Table.DecodePred && !DecodePredicateOperand(MI, 0xE, Address, this))
542         return MCDisassembler::Fail;
543       return Result;
544     }
545   }
546 
547   Result =
548       decodeInstruction(DecoderTableCoProc32, MI, Insn, Address, this, STI);
549   if (Result != MCDisassembler::Fail) {
550     Size = 4;
551     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn, Result);
552   }
553 
554   Size = 4;
555   return MCDisassembler::Fail;
556 }
557 
558 namespace llvm {
559 
560 extern const MCInstrDesc ARMInsts[];
561 
562 } // end namespace llvm
563 
564 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
565 /// immediate Value in the MCInst.  The immediate Value has had any PC
566 /// adjustment made by the caller.  If the instruction is a branch instruction
567 /// then isBranch is true, else false.  If the getOpInfo() function was set as
568 /// part of the setupForSymbolicDisassembly() call then that function is called
569 /// to get any symbolic information at the Address for this instruction.  If
570 /// that returns non-zero then the symbolic information it returns is used to
571 /// create an MCExpr and that is added as an operand to the MCInst.  If
572 /// getOpInfo() returns zero and isBranch is true then a symbol look up for
573 /// Value is done and if a symbol is found an MCExpr is created with that, else
574 /// an MCExpr with Value is created.  This function returns true if it adds an
575 /// operand to the MCInst and false otherwise.
576 static bool tryAddingSymbolicOperand(uint64_t Address, int32_t Value,
577                                      bool isBranch, uint64_t InstSize,
578                                      MCInst &MI, const void *Decoder) {
579   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
580   // FIXME: Does it make sense for value to be negative?
581   return Dis->tryAddingSymbolicOperand(MI, (uint32_t)Value, Address, isBranch,
582                                        /* Offset */ 0, InstSize);
583 }
584 
585 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
586 /// referenced by a load instruction with the base register that is the Pc.
587 /// These can often be values in a literal pool near the Address of the
588 /// instruction.  The Address of the instruction and its immediate Value are
589 /// used as a possible literal pool entry.  The SymbolLookUp call back will
590 /// return the name of a symbol referenced by the literal pool's entry if
591 /// the referenced address is that of a symbol.  Or it will return a pointer to
592 /// a literal 'C' string if the referenced address of the literal pool's entry
593 /// is an address into a section with 'C' string literals.
594 static void tryAddingPcLoadReferenceComment(uint64_t Address, int Value,
595                                             const void *Decoder) {
596   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
597   Dis->tryAddingPcLoadReferenceComment(Value, Address);
598 }
599 
600 // Thumb1 instructions don't have explicit S bits.  Rather, they
601 // implicitly set CPSR.  Since it's not represented in the encoding, the
602 // auto-generated decoder won't inject the CPSR operand.  We need to fix
603 // that as a post-pass.
604 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
605   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
606   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
607   MCInst::iterator I = MI.begin();
608   for (unsigned i = 0; i < NumOps; ++i, ++I) {
609     if (I == MI.end()) break;
610     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
611       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
612       MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
613       return;
614     }
615   }
616 
617   MI.insert(I, MCOperand::createReg(InITBlock ? 0 : ARM::CPSR));
618 }
619 
620 // Most Thumb instructions don't have explicit predicates in the
621 // encoding, but rather get their predicates from IT context.  We need
622 // to fix up the predicate operands using this context information as a
623 // post-pass.
624 MCDisassembler::DecodeStatus
625 ThumbDisassembler::AddThumbPredicate(MCInst &MI) const {
626   MCDisassembler::DecodeStatus S = Success;
627 
628   const FeatureBitset &FeatureBits = getSubtargetInfo().getFeatureBits();
629 
630   // A few instructions actually have predicates encoded in them.  Don't
631   // try to overwrite it if we're seeing one of those.
632   switch (MI.getOpcode()) {
633     case ARM::tBcc:
634     case ARM::t2Bcc:
635     case ARM::tCBZ:
636     case ARM::tCBNZ:
637     case ARM::tCPS:
638     case ARM::t2CPS3p:
639     case ARM::t2CPS2p:
640     case ARM::t2CPS1p:
641     case ARM::t2CSEL:
642     case ARM::t2CSINC:
643     case ARM::t2CSINV:
644     case ARM::t2CSNEG:
645     case ARM::tMOVSr:
646     case ARM::tSETEND:
647       // Some instructions (mostly conditional branches) are not
648       // allowed in IT blocks.
649       if (ITBlock.instrInITBlock())
650         S = SoftFail;
651       else
652         return Success;
653       break;
654     case ARM::t2HINT:
655       if (MI.getOperand(0).getImm() == 0x10 && (FeatureBits[ARM::FeatureRAS]) != 0)
656         S = SoftFail;
657       break;
658     case ARM::tB:
659     case ARM::t2B:
660     case ARM::t2TBB:
661     case ARM::t2TBH:
662       // Some instructions (mostly unconditional branches) can
663       // only appears at the end of, or outside of, an IT.
664       if (ITBlock.instrInITBlock() && !ITBlock.instrLastInITBlock())
665         S = SoftFail;
666       break;
667     default:
668       break;
669   }
670 
671   // If we're in an IT block, base the predicate on that.  Otherwise,
672   // assume a predicate of AL.
673   unsigned CC;
674   CC = ITBlock.getITCC();
675   if (CC == 0xF)
676     CC = ARMCC::AL;
677   if (ITBlock.instrInITBlock())
678     ITBlock.advanceITState();
679 
680   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
681   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
682   MCInst::iterator I = MI.begin();
683   for (unsigned i = 0; i < NumOps; ++i, ++I) {
684     if (I == MI.end()) break;
685     if (OpInfo[i].isPredicate()) {
686       if (CC != ARMCC::AL && !ARMInsts[MI.getOpcode()].isPredicable())
687         Check(S, SoftFail);
688       I = MI.insert(I, MCOperand::createImm(CC));
689       ++I;
690       if (CC == ARMCC::AL)
691         MI.insert(I, MCOperand::createReg(0));
692       else
693         MI.insert(I, MCOperand::createReg(ARM::CPSR));
694       return S;
695     }
696   }
697 
698   I = MI.insert(I, MCOperand::createImm(CC));
699   ++I;
700   if (CC == ARMCC::AL)
701     MI.insert(I, MCOperand::createReg(0));
702   else
703     MI.insert(I, MCOperand::createReg(ARM::CPSR));
704 
705   return S;
706 }
707 
708 // Thumb VFP instructions are a special case.  Because we share their
709 // encodings between ARM and Thumb modes, and they are predicable in ARM
710 // mode, the auto-generated decoder will give them an (incorrect)
711 // predicate operand.  We need to rewrite these operands based on the IT
712 // context as a post-pass.
713 void ThumbDisassembler::UpdateThumbVFPPredicate(
714   DecodeStatus &S, MCInst &MI) const {
715   unsigned CC;
716   CC = ITBlock.getITCC();
717   if (CC == 0xF)
718     CC = ARMCC::AL;
719   if (ITBlock.instrInITBlock())
720     ITBlock.advanceITState();
721 
722   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
723   MCInst::iterator I = MI.begin();
724   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
725   for (unsigned i = 0; i < NumOps; ++i, ++I) {
726     if (OpInfo[i].isPredicate() ) {
727       if (CC != ARMCC::AL && !ARMInsts[MI.getOpcode()].isPredicable())
728         Check(S, SoftFail);
729       I->setImm(CC);
730       ++I;
731       if (CC == ARMCC::AL)
732         I->setReg(0);
733       else
734         I->setReg(ARM::CPSR);
735       return;
736     }
737   }
738 }
739 
740 DecodeStatus ThumbDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
741                                                ArrayRef<uint8_t> Bytes,
742                                                uint64_t Address,
743                                                raw_ostream &OS,
744                                                raw_ostream &CS) const {
745   CommentStream = &CS;
746 
747   assert(STI.getFeatureBits()[ARM::ModeThumb] &&
748          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
749 
750   // We want to read exactly 2 bytes of data.
751   if (Bytes.size() < 2) {
752     Size = 0;
753     return MCDisassembler::Fail;
754   }
755 
756   uint16_t Insn16 = (Bytes[1] << 8) | Bytes[0];
757   DecodeStatus Result =
758       decodeInstruction(DecoderTableThumb16, MI, Insn16, Address, this, STI);
759   if (Result != MCDisassembler::Fail) {
760     Size = 2;
761     Check(Result, AddThumbPredicate(MI));
762     return Result;
763   }
764 
765   Result = decodeInstruction(DecoderTableThumbSBit16, MI, Insn16, Address, this,
766                              STI);
767   if (Result) {
768     Size = 2;
769     bool InITBlock = ITBlock.instrInITBlock();
770     Check(Result, AddThumbPredicate(MI));
771     AddThumb1SBit(MI, InITBlock);
772     return Result;
773   }
774 
775   Result =
776       decodeInstruction(DecoderTableThumb216, MI, Insn16, Address, this, STI);
777   if (Result != MCDisassembler::Fail) {
778     Size = 2;
779 
780     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
781     // the Thumb predicate.
782     if (MI.getOpcode() == ARM::t2IT && ITBlock.instrInITBlock())
783       Result = MCDisassembler::SoftFail;
784 
785     Check(Result, AddThumbPredicate(MI));
786 
787     // If we find an IT instruction, we need to parse its condition
788     // code and mask operands so that we can apply them correctly
789     // to the subsequent instructions.
790     if (MI.getOpcode() == ARM::t2IT) {
791       unsigned Firstcond = MI.getOperand(0).getImm();
792       unsigned Mask = MI.getOperand(1).getImm();
793       ITBlock.setITState(Firstcond, Mask);
794 
795       // An IT instruction that would give a 'NV' predicate is unpredictable.
796       if (Firstcond == ARMCC::AL && !isPowerOf2_32(Mask))
797         CS << "unpredictable IT predicate sequence";
798     }
799 
800     return Result;
801   }
802 
803   // We want to read exactly 4 bytes of data.
804   if (Bytes.size() < 4) {
805     Size = 0;
806     return MCDisassembler::Fail;
807   }
808 
809   uint32_t Insn32 =
810       (Bytes[3] << 8) | (Bytes[2] << 0) | (Bytes[1] << 24) | (Bytes[0] << 16);
811 
812   Result =
813       decodeInstruction(DecoderTableMVE32, MI, Insn32, Address, this, STI);
814   if (Result != MCDisassembler::Fail) {
815     Size = 4;
816     Check(Result, AddThumbPredicate(MI));
817     return Result;
818   }
819 
820   Result =
821       decodeInstruction(DecoderTableThumb32, MI, Insn32, Address, this, STI);
822   if (Result != MCDisassembler::Fail) {
823     Size = 4;
824     bool InITBlock = ITBlock.instrInITBlock();
825     Check(Result, AddThumbPredicate(MI));
826     AddThumb1SBit(MI, InITBlock);
827     return Result;
828   }
829 
830   Result =
831       decodeInstruction(DecoderTableThumb232, MI, Insn32, Address, this, STI);
832   if (Result != MCDisassembler::Fail) {
833     Size = 4;
834     Check(Result, AddThumbPredicate(MI));
835     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn32, Result);
836   }
837 
838   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
839     Result =
840         decodeInstruction(DecoderTableVFP32, MI, Insn32, Address, this, STI);
841     if (Result != MCDisassembler::Fail) {
842       Size = 4;
843       UpdateThumbVFPPredicate(Result, MI);
844       return Result;
845     }
846   }
847 
848   Result =
849       decodeInstruction(DecoderTableVFPV832, MI, Insn32, Address, this, STI);
850   if (Result != MCDisassembler::Fail) {
851     Size = 4;
852     return Result;
853   }
854 
855   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
856     Result = decodeInstruction(DecoderTableNEONDup32, MI, Insn32, Address, this,
857                                STI);
858     if (Result != MCDisassembler::Fail) {
859       Size = 4;
860       Check(Result, AddThumbPredicate(MI));
861       return Result;
862     }
863   }
864 
865   if (fieldFromInstruction(Insn32, 24, 8) == 0xF9) {
866     uint32_t NEONLdStInsn = Insn32;
867     NEONLdStInsn &= 0xF0FFFFFF;
868     NEONLdStInsn |= 0x04000000;
869     Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, NEONLdStInsn,
870                                Address, this, STI);
871     if (Result != MCDisassembler::Fail) {
872       Size = 4;
873       Check(Result, AddThumbPredicate(MI));
874       return Result;
875     }
876   }
877 
878   if (fieldFromInstruction(Insn32, 24, 4) == 0xF) {
879     uint32_t NEONDataInsn = Insn32;
880     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
881     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
882     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
883     Result = decodeInstruction(DecoderTableNEONData32, MI, NEONDataInsn,
884                                Address, this, STI);
885     if (Result != MCDisassembler::Fail) {
886       Size = 4;
887       Check(Result, AddThumbPredicate(MI));
888       return Result;
889     }
890 
891     uint32_t NEONCryptoInsn = Insn32;
892     NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
893     NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
894     NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
895     Result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
896                                Address, this, STI);
897     if (Result != MCDisassembler::Fail) {
898       Size = 4;
899       return Result;
900     }
901 
902     uint32_t NEONv8Insn = Insn32;
903     NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
904     Result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
905                                this, STI);
906     if (Result != MCDisassembler::Fail) {
907       Size = 4;
908       return Result;
909     }
910   }
911 
912   Result =
913       decodeInstruction(DecoderTableThumb2CoProc32, MI, Insn32, Address, this, STI);
914   if (Result != MCDisassembler::Fail) {
915     Size = 4;
916     Check(Result, AddThumbPredicate(MI));
917     return Result;
918   }
919 
920   Size = 0;
921   return MCDisassembler::Fail;
922 }
923 
924 extern "C" void LLVMInitializeARMDisassembler() {
925   TargetRegistry::RegisterMCDisassembler(getTheARMLETarget(),
926                                          createARMDisassembler);
927   TargetRegistry::RegisterMCDisassembler(getTheARMBETarget(),
928                                          createARMDisassembler);
929   TargetRegistry::RegisterMCDisassembler(getTheThumbLETarget(),
930                                          createThumbDisassembler);
931   TargetRegistry::RegisterMCDisassembler(getTheThumbBETarget(),
932                                          createThumbDisassembler);
933 }
934 
935 static const uint16_t GPRDecoderTable[] = {
936   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
937   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
938   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
939   ARM::R12, ARM::SP, ARM::LR, ARM::PC
940 };
941 
942 static const uint16_t CLRMGPRDecoderTable[] = {
943   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
944   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
945   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
946   ARM::R12, 0, ARM::LR, ARM::APSR
947 };
948 
949 static DecodeStatus DecodeGPRRegisterClass(MCInst &Inst, unsigned RegNo,
950                                    uint64_t Address, const void *Decoder) {
951   if (RegNo > 15)
952     return MCDisassembler::Fail;
953 
954   unsigned Register = GPRDecoderTable[RegNo];
955   Inst.addOperand(MCOperand::createReg(Register));
956   return MCDisassembler::Success;
957 }
958 
959 static DecodeStatus DecodeCLRMGPRRegisterClass(MCInst &Inst, unsigned RegNo,
960                                                uint64_t Address,
961                                                const void *Decoder) {
962   if (RegNo > 15)
963     return MCDisassembler::Fail;
964 
965   unsigned Register = CLRMGPRDecoderTable[RegNo];
966   if (Register == 0)
967     return MCDisassembler::Fail;
968 
969   Inst.addOperand(MCOperand::createReg(Register));
970   return MCDisassembler::Success;
971 }
972 
973 static DecodeStatus
974 DecodeGPRnopcRegisterClass(MCInst &Inst, unsigned RegNo,
975                            uint64_t Address, const void *Decoder) {
976   DecodeStatus S = MCDisassembler::Success;
977 
978   if (RegNo == 15)
979     S = MCDisassembler::SoftFail;
980 
981   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
982 
983   return S;
984 }
985 
986 static DecodeStatus
987 DecodeGPRwithAPSRRegisterClass(MCInst &Inst, unsigned RegNo,
988                                uint64_t Address, const void *Decoder) {
989   DecodeStatus S = MCDisassembler::Success;
990 
991   if (RegNo == 15)
992   {
993     Inst.addOperand(MCOperand::createReg(ARM::APSR_NZCV));
994     return MCDisassembler::Success;
995   }
996 
997   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
998   return S;
999 }
1000 
1001 static DecodeStatus
1002 DecodeGPRwithZRRegisterClass(MCInst &Inst, unsigned RegNo,
1003                              uint64_t Address, const void *Decoder) {
1004   DecodeStatus S = MCDisassembler::Success;
1005 
1006   if (RegNo == 15)
1007   {
1008     Inst.addOperand(MCOperand::createReg(ARM::ZR));
1009     return MCDisassembler::Success;
1010   }
1011 
1012   if (RegNo == 13)
1013     S = MCDisassembler::SoftFail;
1014 
1015   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1016   return S;
1017 }
1018 
1019 static DecodeStatus DecodetGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1020                                    uint64_t Address, const void *Decoder) {
1021   if (RegNo > 7)
1022     return MCDisassembler::Fail;
1023   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
1024 }
1025 
1026 static const uint16_t GPRPairDecoderTable[] = {
1027   ARM::R0_R1, ARM::R2_R3,   ARM::R4_R5,  ARM::R6_R7,
1028   ARM::R8_R9, ARM::R10_R11, ARM::R12_SP
1029 };
1030 
1031 static DecodeStatus DecodeGPRPairRegisterClass(MCInst &Inst, unsigned RegNo,
1032                                    uint64_t Address, const void *Decoder) {
1033   DecodeStatus S = MCDisassembler::Success;
1034 
1035   if (RegNo > 13)
1036     return MCDisassembler::Fail;
1037 
1038   if ((RegNo & 1) || RegNo == 0xe)
1039      S = MCDisassembler::SoftFail;
1040 
1041   unsigned RegisterPair = GPRPairDecoderTable[RegNo/2];
1042   Inst.addOperand(MCOperand::createReg(RegisterPair));
1043   return S;
1044 }
1045 
1046 static DecodeStatus DecodetcGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1047                                    uint64_t Address, const void *Decoder) {
1048   unsigned Register = 0;
1049   switch (RegNo) {
1050     case 0:
1051       Register = ARM::R0;
1052       break;
1053     case 1:
1054       Register = ARM::R1;
1055       break;
1056     case 2:
1057       Register = ARM::R2;
1058       break;
1059     case 3:
1060       Register = ARM::R3;
1061       break;
1062     case 9:
1063       Register = ARM::R9;
1064       break;
1065     case 12:
1066       Register = ARM::R12;
1067       break;
1068     default:
1069       return MCDisassembler::Fail;
1070     }
1071 
1072   Inst.addOperand(MCOperand::createReg(Register));
1073   return MCDisassembler::Success;
1074 }
1075 
1076 static DecodeStatus DecoderGPRRegisterClass(MCInst &Inst, unsigned RegNo,
1077                                    uint64_t Address, const void *Decoder) {
1078   DecodeStatus S = MCDisassembler::Success;
1079 
1080   const FeatureBitset &featureBits =
1081     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1082 
1083   if ((RegNo == 13 && !featureBits[ARM::HasV8Ops]) || RegNo == 15)
1084     S = MCDisassembler::SoftFail;
1085 
1086   Check(S, DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder));
1087   return S;
1088 }
1089 
1090 static const uint16_t SPRDecoderTable[] = {
1091      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
1092      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
1093      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
1094     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
1095     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
1096     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
1097     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
1098     ARM::S28, ARM::S29, ARM::S30, ARM::S31
1099 };
1100 
1101 static DecodeStatus DecodeSPRRegisterClass(MCInst &Inst, unsigned RegNo,
1102                                    uint64_t Address, const void *Decoder) {
1103   if (RegNo > 31)
1104     return MCDisassembler::Fail;
1105 
1106   unsigned Register = SPRDecoderTable[RegNo];
1107   Inst.addOperand(MCOperand::createReg(Register));
1108   return MCDisassembler::Success;
1109 }
1110 
1111 static DecodeStatus DecodeHPRRegisterClass(MCInst &Inst, unsigned RegNo,
1112                                    uint64_t Address, const void *Decoder) {
1113   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1114 }
1115 
1116 static const uint16_t DPRDecoderTable[] = {
1117      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
1118      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
1119      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
1120     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
1121     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
1122     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
1123     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
1124     ARM::D28, ARM::D29, ARM::D30, ARM::D31
1125 };
1126 
1127 static DecodeStatus DecodeDPRRegisterClass(MCInst &Inst, unsigned RegNo,
1128                                    uint64_t Address, const void *Decoder) {
1129   const FeatureBitset &featureBits =
1130     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1131 
1132   bool hasD32 = featureBits[ARM::FeatureD32];
1133 
1134   if (RegNo > 31 || (!hasD32 && RegNo > 15))
1135     return MCDisassembler::Fail;
1136 
1137   unsigned Register = DPRDecoderTable[RegNo];
1138   Inst.addOperand(MCOperand::createReg(Register));
1139   return MCDisassembler::Success;
1140 }
1141 
1142 static DecodeStatus DecodeDPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1143                                    uint64_t Address, const void *Decoder) {
1144   if (RegNo > 7)
1145     return MCDisassembler::Fail;
1146   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1147 }
1148 
1149 static DecodeStatus DecodeSPR_8RegisterClass(MCInst &Inst, unsigned RegNo,
1150                                    uint64_t Address, const void *Decoder) {
1151   if (RegNo > 15)
1152     return MCDisassembler::Fail;
1153   return DecodeSPRRegisterClass(Inst, RegNo, Address, Decoder);
1154 }
1155 
1156 static DecodeStatus
1157 DecodeDPR_VFP2RegisterClass(MCInst &Inst, unsigned RegNo,
1158                             uint64_t Address, const void *Decoder) {
1159   if (RegNo > 15)
1160     return MCDisassembler::Fail;
1161   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
1162 }
1163 
1164 static const uint16_t QPRDecoderTable[] = {
1165      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
1166      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
1167      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
1168     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
1169 };
1170 
1171 static DecodeStatus DecodeQPRRegisterClass(MCInst &Inst, unsigned RegNo,
1172                                    uint64_t Address, const void *Decoder) {
1173   if (RegNo > 31 || (RegNo & 1) != 0)
1174     return MCDisassembler::Fail;
1175   RegNo >>= 1;
1176 
1177   unsigned Register = QPRDecoderTable[RegNo];
1178   Inst.addOperand(MCOperand::createReg(Register));
1179   return MCDisassembler::Success;
1180 }
1181 
1182 static const uint16_t DPairDecoderTable[] = {
1183   ARM::Q0,  ARM::D1_D2,   ARM::Q1,  ARM::D3_D4,   ARM::Q2,  ARM::D5_D6,
1184   ARM::Q3,  ARM::D7_D8,   ARM::Q4,  ARM::D9_D10,  ARM::Q5,  ARM::D11_D12,
1185   ARM::Q6,  ARM::D13_D14, ARM::Q7,  ARM::D15_D16, ARM::Q8,  ARM::D17_D18,
1186   ARM::Q9,  ARM::D19_D20, ARM::Q10, ARM::D21_D22, ARM::Q11, ARM::D23_D24,
1187   ARM::Q12, ARM::D25_D26, ARM::Q13, ARM::D27_D28, ARM::Q14, ARM::D29_D30,
1188   ARM::Q15
1189 };
1190 
1191 static DecodeStatus DecodeDPairRegisterClass(MCInst &Inst, unsigned RegNo,
1192                                    uint64_t Address, const void *Decoder) {
1193   if (RegNo > 30)
1194     return MCDisassembler::Fail;
1195 
1196   unsigned Register = DPairDecoderTable[RegNo];
1197   Inst.addOperand(MCOperand::createReg(Register));
1198   return MCDisassembler::Success;
1199 }
1200 
1201 static const uint16_t DPairSpacedDecoderTable[] = {
1202   ARM::D0_D2,   ARM::D1_D3,   ARM::D2_D4,   ARM::D3_D5,
1203   ARM::D4_D6,   ARM::D5_D7,   ARM::D6_D8,   ARM::D7_D9,
1204   ARM::D8_D10,  ARM::D9_D11,  ARM::D10_D12, ARM::D11_D13,
1205   ARM::D12_D14, ARM::D13_D15, ARM::D14_D16, ARM::D15_D17,
1206   ARM::D16_D18, ARM::D17_D19, ARM::D18_D20, ARM::D19_D21,
1207   ARM::D20_D22, ARM::D21_D23, ARM::D22_D24, ARM::D23_D25,
1208   ARM::D24_D26, ARM::D25_D27, ARM::D26_D28, ARM::D27_D29,
1209   ARM::D28_D30, ARM::D29_D31
1210 };
1211 
1212 static DecodeStatus DecodeDPairSpacedRegisterClass(MCInst &Inst,
1213                                                    unsigned RegNo,
1214                                                    uint64_t Address,
1215                                                    const void *Decoder) {
1216   if (RegNo > 29)
1217     return MCDisassembler::Fail;
1218 
1219   unsigned Register = DPairSpacedDecoderTable[RegNo];
1220   Inst.addOperand(MCOperand::createReg(Register));
1221   return MCDisassembler::Success;
1222 }
1223 
1224 static DecodeStatus DecodePredicateOperand(MCInst &Inst, unsigned Val,
1225                                uint64_t Address, const void *Decoder) {
1226   DecodeStatus S = MCDisassembler::Success;
1227   if (Val == 0xF) return MCDisassembler::Fail;
1228   // AL predicate is not allowed on Thumb1 branches.
1229   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
1230     return MCDisassembler::Fail;
1231   if (Val != ARMCC::AL && !ARMInsts[Inst.getOpcode()].isPredicable())
1232     Check(S, MCDisassembler::SoftFail);
1233   Inst.addOperand(MCOperand::createImm(Val));
1234   if (Val == ARMCC::AL) {
1235     Inst.addOperand(MCOperand::createReg(0));
1236   } else
1237     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1238   return S;
1239 }
1240 
1241 static DecodeStatus DecodeCCOutOperand(MCInst &Inst, unsigned Val,
1242                                uint64_t Address, const void *Decoder) {
1243   if (Val)
1244     Inst.addOperand(MCOperand::createReg(ARM::CPSR));
1245   else
1246     Inst.addOperand(MCOperand::createReg(0));
1247   return MCDisassembler::Success;
1248 }
1249 
1250 static DecodeStatus DecodeSORegImmOperand(MCInst &Inst, unsigned Val,
1251                                uint64_t Address, const void *Decoder) {
1252   DecodeStatus S = MCDisassembler::Success;
1253 
1254   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1255   unsigned type = fieldFromInstruction(Val, 5, 2);
1256   unsigned imm = fieldFromInstruction(Val, 7, 5);
1257 
1258   // Register-immediate
1259   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
1260     return MCDisassembler::Fail;
1261 
1262   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1263   switch (type) {
1264     case 0:
1265       Shift = ARM_AM::lsl;
1266       break;
1267     case 1:
1268       Shift = ARM_AM::lsr;
1269       break;
1270     case 2:
1271       Shift = ARM_AM::asr;
1272       break;
1273     case 3:
1274       Shift = ARM_AM::ror;
1275       break;
1276   }
1277 
1278   if (Shift == ARM_AM::ror && imm == 0)
1279     Shift = ARM_AM::rrx;
1280 
1281   unsigned Op = Shift | (imm << 3);
1282   Inst.addOperand(MCOperand::createImm(Op));
1283 
1284   return S;
1285 }
1286 
1287 static DecodeStatus DecodeSORegRegOperand(MCInst &Inst, unsigned Val,
1288                                uint64_t Address, const void *Decoder) {
1289   DecodeStatus S = MCDisassembler::Success;
1290 
1291   unsigned Rm = fieldFromInstruction(Val, 0, 4);
1292   unsigned type = fieldFromInstruction(Val, 5, 2);
1293   unsigned Rs = fieldFromInstruction(Val, 8, 4);
1294 
1295   // Register-register
1296   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1297     return MCDisassembler::Fail;
1298   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1299     return MCDisassembler::Fail;
1300 
1301   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1302   switch (type) {
1303     case 0:
1304       Shift = ARM_AM::lsl;
1305       break;
1306     case 1:
1307       Shift = ARM_AM::lsr;
1308       break;
1309     case 2:
1310       Shift = ARM_AM::asr;
1311       break;
1312     case 3:
1313       Shift = ARM_AM::ror;
1314       break;
1315   }
1316 
1317   Inst.addOperand(MCOperand::createImm(Shift));
1318 
1319   return S;
1320 }
1321 
1322 static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Val,
1323                                  uint64_t Address, const void *Decoder) {
1324   DecodeStatus S = MCDisassembler::Success;
1325 
1326   bool NeedDisjointWriteback = false;
1327   unsigned WritebackReg = 0;
1328   bool CLRM = false;
1329   switch (Inst.getOpcode()) {
1330   default:
1331     break;
1332   case ARM::LDMIA_UPD:
1333   case ARM::LDMDB_UPD:
1334   case ARM::LDMIB_UPD:
1335   case ARM::LDMDA_UPD:
1336   case ARM::t2LDMIA_UPD:
1337   case ARM::t2LDMDB_UPD:
1338   case ARM::t2STMIA_UPD:
1339   case ARM::t2STMDB_UPD:
1340     NeedDisjointWriteback = true;
1341     WritebackReg = Inst.getOperand(0).getReg();
1342     break;
1343   case ARM::t2CLRM:
1344     CLRM = true;
1345     break;
1346   }
1347 
1348   // Empty register lists are not allowed.
1349   if (Val == 0) return MCDisassembler::Fail;
1350   for (unsigned i = 0; i < 16; ++i) {
1351     if (Val & (1 << i)) {
1352       if (CLRM) {
1353         if (!Check(S, DecodeCLRMGPRRegisterClass(Inst, i, Address, Decoder))) {
1354           return MCDisassembler::Fail;
1355         }
1356       } else {
1357         if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1358           return MCDisassembler::Fail;
1359         // Writeback not allowed if Rn is in the target list.
1360         if (NeedDisjointWriteback && WritebackReg == Inst.end()[-1].getReg())
1361           Check(S, MCDisassembler::SoftFail);
1362       }
1363     }
1364   }
1365 
1366   return S;
1367 }
1368 
1369 static DecodeStatus DecodeSPRRegListOperand(MCInst &Inst, unsigned Val,
1370                                  uint64_t Address, const void *Decoder) {
1371   DecodeStatus S = MCDisassembler::Success;
1372 
1373   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1374   unsigned regs = fieldFromInstruction(Val, 0, 8);
1375 
1376   // In case of unpredictable encoding, tweak the operands.
1377   if (regs == 0 || (Vd + regs) > 32) {
1378     regs = Vd + regs > 32 ? 32 - Vd : regs;
1379     regs = std::max( 1u, regs);
1380     S = MCDisassembler::SoftFail;
1381   }
1382 
1383   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1384     return MCDisassembler::Fail;
1385   for (unsigned i = 0; i < (regs - 1); ++i) {
1386     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1387       return MCDisassembler::Fail;
1388   }
1389 
1390   return S;
1391 }
1392 
1393 static DecodeStatus DecodeDPRRegListOperand(MCInst &Inst, unsigned Val,
1394                                  uint64_t Address, const void *Decoder) {
1395   DecodeStatus S = MCDisassembler::Success;
1396 
1397   unsigned Vd = fieldFromInstruction(Val, 8, 5);
1398   unsigned regs = fieldFromInstruction(Val, 1, 7);
1399 
1400   // In case of unpredictable encoding, tweak the operands.
1401   if (regs == 0 || regs > 16 || (Vd + regs) > 32) {
1402     regs = Vd + regs > 32 ? 32 - Vd : regs;
1403     regs = std::max( 1u, regs);
1404     regs = std::min(16u, regs);
1405     S = MCDisassembler::SoftFail;
1406   }
1407 
1408   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1409       return MCDisassembler::Fail;
1410   for (unsigned i = 0; i < (regs - 1); ++i) {
1411     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1412       return MCDisassembler::Fail;
1413   }
1414 
1415   return S;
1416 }
1417 
1418 static DecodeStatus DecodeBitfieldMaskOperand(MCInst &Inst, unsigned Val,
1419                                       uint64_t Address, const void *Decoder) {
1420   // This operand encodes a mask of contiguous zeros between a specified MSB
1421   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1422   // the mask of all bits LSB-and-lower, and then xor them to create
1423   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1424   // create the final mask.
1425   unsigned msb = fieldFromInstruction(Val, 5, 5);
1426   unsigned lsb = fieldFromInstruction(Val, 0, 5);
1427 
1428   DecodeStatus S = MCDisassembler::Success;
1429   if (lsb > msb) {
1430     Check(S, MCDisassembler::SoftFail);
1431     // The check above will cause the warning for the "potentially undefined
1432     // instruction encoding" but we can't build a bad MCOperand value here
1433     // with a lsb > msb or else printing the MCInst will cause a crash.
1434     lsb = msb;
1435   }
1436 
1437   uint32_t msb_mask = 0xFFFFFFFF;
1438   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1439   uint32_t lsb_mask = (1U << lsb) - 1;
1440 
1441   Inst.addOperand(MCOperand::createImm(~(msb_mask ^ lsb_mask)));
1442   return S;
1443 }
1444 
1445 static DecodeStatus DecodeCopMemInstruction(MCInst &Inst, unsigned Insn,
1446                                   uint64_t Address, const void *Decoder) {
1447   DecodeStatus S = MCDisassembler::Success;
1448 
1449   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1450   unsigned CRd = fieldFromInstruction(Insn, 12, 4);
1451   unsigned coproc = fieldFromInstruction(Insn, 8, 4);
1452   unsigned imm = fieldFromInstruction(Insn, 0, 8);
1453   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1454   unsigned U = fieldFromInstruction(Insn, 23, 1);
1455   const FeatureBitset &featureBits =
1456     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
1457 
1458   switch (Inst.getOpcode()) {
1459     case ARM::LDC_OFFSET:
1460     case ARM::LDC_PRE:
1461     case ARM::LDC_POST:
1462     case ARM::LDC_OPTION:
1463     case ARM::LDCL_OFFSET:
1464     case ARM::LDCL_PRE:
1465     case ARM::LDCL_POST:
1466     case ARM::LDCL_OPTION:
1467     case ARM::STC_OFFSET:
1468     case ARM::STC_PRE:
1469     case ARM::STC_POST:
1470     case ARM::STC_OPTION:
1471     case ARM::STCL_OFFSET:
1472     case ARM::STCL_PRE:
1473     case ARM::STCL_POST:
1474     case ARM::STCL_OPTION:
1475     case ARM::t2LDC_OFFSET:
1476     case ARM::t2LDC_PRE:
1477     case ARM::t2LDC_POST:
1478     case ARM::t2LDC_OPTION:
1479     case ARM::t2LDCL_OFFSET:
1480     case ARM::t2LDCL_PRE:
1481     case ARM::t2LDCL_POST:
1482     case ARM::t2LDCL_OPTION:
1483     case ARM::t2STC_OFFSET:
1484     case ARM::t2STC_PRE:
1485     case ARM::t2STC_POST:
1486     case ARM::t2STC_OPTION:
1487     case ARM::t2STCL_OFFSET:
1488     case ARM::t2STCL_PRE:
1489     case ARM::t2STCL_POST:
1490     case ARM::t2STCL_OPTION:
1491     case ARM::t2LDC2_OFFSET:
1492     case ARM::t2LDC2L_OFFSET:
1493     case ARM::t2LDC2_PRE:
1494     case ARM::t2LDC2L_PRE:
1495     case ARM::t2STC2_OFFSET:
1496     case ARM::t2STC2L_OFFSET:
1497     case ARM::t2STC2_PRE:
1498     case ARM::t2STC2L_PRE:
1499     case ARM::LDC2_OFFSET:
1500     case ARM::LDC2L_OFFSET:
1501     case ARM::LDC2_PRE:
1502     case ARM::LDC2L_PRE:
1503     case ARM::STC2_OFFSET:
1504     case ARM::STC2L_OFFSET:
1505     case ARM::STC2_PRE:
1506     case ARM::STC2L_PRE:
1507     case ARM::t2LDC2_OPTION:
1508     case ARM::t2STC2_OPTION:
1509     case ARM::t2LDC2_POST:
1510     case ARM::t2LDC2L_POST:
1511     case ARM::t2STC2_POST:
1512     case ARM::t2STC2L_POST:
1513     case ARM::LDC2_POST:
1514     case ARM::LDC2L_POST:
1515     case ARM::STC2_POST:
1516     case ARM::STC2L_POST:
1517       if (coproc == 0xA || coproc == 0xB ||
1518           (featureBits[ARM::HasV8_1MMainlineOps] &&
1519            (coproc == 0x8 || coproc == 0x9 || coproc == 0xA || coproc == 0xB ||
1520             coproc == 0xE || coproc == 0xF)))
1521         return MCDisassembler::Fail;
1522       break;
1523     default:
1524       break;
1525   }
1526 
1527   if (featureBits[ARM::HasV8Ops] && (coproc != 14))
1528     return MCDisassembler::Fail;
1529 
1530   Inst.addOperand(MCOperand::createImm(coproc));
1531   Inst.addOperand(MCOperand::createImm(CRd));
1532   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1533     return MCDisassembler::Fail;
1534 
1535   switch (Inst.getOpcode()) {
1536     case ARM::t2LDC2_OFFSET:
1537     case ARM::t2LDC2L_OFFSET:
1538     case ARM::t2LDC2_PRE:
1539     case ARM::t2LDC2L_PRE:
1540     case ARM::t2STC2_OFFSET:
1541     case ARM::t2STC2L_OFFSET:
1542     case ARM::t2STC2_PRE:
1543     case ARM::t2STC2L_PRE:
1544     case ARM::LDC2_OFFSET:
1545     case ARM::LDC2L_OFFSET:
1546     case ARM::LDC2_PRE:
1547     case ARM::LDC2L_PRE:
1548     case ARM::STC2_OFFSET:
1549     case ARM::STC2L_OFFSET:
1550     case ARM::STC2_PRE:
1551     case ARM::STC2L_PRE:
1552     case ARM::t2LDC_OFFSET:
1553     case ARM::t2LDCL_OFFSET:
1554     case ARM::t2LDC_PRE:
1555     case ARM::t2LDCL_PRE:
1556     case ARM::t2STC_OFFSET:
1557     case ARM::t2STCL_OFFSET:
1558     case ARM::t2STC_PRE:
1559     case ARM::t2STCL_PRE:
1560     case ARM::LDC_OFFSET:
1561     case ARM::LDCL_OFFSET:
1562     case ARM::LDC_PRE:
1563     case ARM::LDCL_PRE:
1564     case ARM::STC_OFFSET:
1565     case ARM::STCL_OFFSET:
1566     case ARM::STC_PRE:
1567     case ARM::STCL_PRE:
1568       imm = ARM_AM::getAM5Opc(U ? ARM_AM::add : ARM_AM::sub, imm);
1569       Inst.addOperand(MCOperand::createImm(imm));
1570       break;
1571     case ARM::t2LDC2_POST:
1572     case ARM::t2LDC2L_POST:
1573     case ARM::t2STC2_POST:
1574     case ARM::t2STC2L_POST:
1575     case ARM::LDC2_POST:
1576     case ARM::LDC2L_POST:
1577     case ARM::STC2_POST:
1578     case ARM::STC2L_POST:
1579     case ARM::t2LDC_POST:
1580     case ARM::t2LDCL_POST:
1581     case ARM::t2STC_POST:
1582     case ARM::t2STCL_POST:
1583     case ARM::LDC_POST:
1584     case ARM::LDCL_POST:
1585     case ARM::STC_POST:
1586     case ARM::STCL_POST:
1587       imm |= U << 8;
1588       LLVM_FALLTHROUGH;
1589     default:
1590       // The 'option' variant doesn't encode 'U' in the immediate since
1591       // the immediate is unsigned [0,255].
1592       Inst.addOperand(MCOperand::createImm(imm));
1593       break;
1594   }
1595 
1596   switch (Inst.getOpcode()) {
1597     case ARM::LDC_OFFSET:
1598     case ARM::LDC_PRE:
1599     case ARM::LDC_POST:
1600     case ARM::LDC_OPTION:
1601     case ARM::LDCL_OFFSET:
1602     case ARM::LDCL_PRE:
1603     case ARM::LDCL_POST:
1604     case ARM::LDCL_OPTION:
1605     case ARM::STC_OFFSET:
1606     case ARM::STC_PRE:
1607     case ARM::STC_POST:
1608     case ARM::STC_OPTION:
1609     case ARM::STCL_OFFSET:
1610     case ARM::STCL_PRE:
1611     case ARM::STCL_POST:
1612     case ARM::STCL_OPTION:
1613       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1614         return MCDisassembler::Fail;
1615       break;
1616     default:
1617       break;
1618   }
1619 
1620   return S;
1621 }
1622 
1623 static DecodeStatus
1624 DecodeAddrMode2IdxInstruction(MCInst &Inst, unsigned Insn,
1625                               uint64_t Address, const void *Decoder) {
1626   DecodeStatus S = MCDisassembler::Success;
1627 
1628   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1629   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1630   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1631   unsigned imm = fieldFromInstruction(Insn, 0, 12);
1632   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1633   unsigned reg = fieldFromInstruction(Insn, 25, 1);
1634   unsigned P = fieldFromInstruction(Insn, 24, 1);
1635   unsigned W = fieldFromInstruction(Insn, 21, 1);
1636 
1637   // On stores, the writeback operand precedes Rt.
1638   switch (Inst.getOpcode()) {
1639     case ARM::STR_POST_IMM:
1640     case ARM::STR_POST_REG:
1641     case ARM::STRB_POST_IMM:
1642     case ARM::STRB_POST_REG:
1643     case ARM::STRT_POST_REG:
1644     case ARM::STRT_POST_IMM:
1645     case ARM::STRBT_POST_REG:
1646     case ARM::STRBT_POST_IMM:
1647       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1648         return MCDisassembler::Fail;
1649       break;
1650     default:
1651       break;
1652   }
1653 
1654   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1655     return MCDisassembler::Fail;
1656 
1657   // On loads, the writeback operand comes after Rt.
1658   switch (Inst.getOpcode()) {
1659     case ARM::LDR_POST_IMM:
1660     case ARM::LDR_POST_REG:
1661     case ARM::LDRB_POST_IMM:
1662     case ARM::LDRB_POST_REG:
1663     case ARM::LDRBT_POST_REG:
1664     case ARM::LDRBT_POST_IMM:
1665     case ARM::LDRT_POST_REG:
1666     case ARM::LDRT_POST_IMM:
1667       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1668         return MCDisassembler::Fail;
1669       break;
1670     default:
1671       break;
1672   }
1673 
1674   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1675     return MCDisassembler::Fail;
1676 
1677   ARM_AM::AddrOpc Op = ARM_AM::add;
1678   if (!fieldFromInstruction(Insn, 23, 1))
1679     Op = ARM_AM::sub;
1680 
1681   bool writeback = (P == 0) || (W == 1);
1682   unsigned idx_mode = 0;
1683   if (P && writeback)
1684     idx_mode = ARMII::IndexModePre;
1685   else if (!P && writeback)
1686     idx_mode = ARMII::IndexModePost;
1687 
1688   if (writeback && (Rn == 15 || Rn == Rt))
1689     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1690 
1691   if (reg) {
1692     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1693       return MCDisassembler::Fail;
1694     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1695     switch( fieldFromInstruction(Insn, 5, 2)) {
1696       case 0:
1697         Opc = ARM_AM::lsl;
1698         break;
1699       case 1:
1700         Opc = ARM_AM::lsr;
1701         break;
1702       case 2:
1703         Opc = ARM_AM::asr;
1704         break;
1705       case 3:
1706         Opc = ARM_AM::ror;
1707         break;
1708       default:
1709         return MCDisassembler::Fail;
1710     }
1711     unsigned amt = fieldFromInstruction(Insn, 7, 5);
1712     if (Opc == ARM_AM::ror && amt == 0)
1713       Opc = ARM_AM::rrx;
1714     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1715 
1716     Inst.addOperand(MCOperand::createImm(imm));
1717   } else {
1718     Inst.addOperand(MCOperand::createReg(0));
1719     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1720     Inst.addOperand(MCOperand::createImm(tmp));
1721   }
1722 
1723   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1724     return MCDisassembler::Fail;
1725 
1726   return S;
1727 }
1728 
1729 static DecodeStatus DecodeSORegMemOperand(MCInst &Inst, unsigned Val,
1730                                   uint64_t Address, const void *Decoder) {
1731   DecodeStatus S = MCDisassembler::Success;
1732 
1733   unsigned Rn = fieldFromInstruction(Val, 13, 4);
1734   unsigned Rm = fieldFromInstruction(Val,  0, 4);
1735   unsigned type = fieldFromInstruction(Val, 5, 2);
1736   unsigned imm = fieldFromInstruction(Val, 7, 5);
1737   unsigned U = fieldFromInstruction(Val, 12, 1);
1738 
1739   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1740   switch (type) {
1741     case 0:
1742       ShOp = ARM_AM::lsl;
1743       break;
1744     case 1:
1745       ShOp = ARM_AM::lsr;
1746       break;
1747     case 2:
1748       ShOp = ARM_AM::asr;
1749       break;
1750     case 3:
1751       ShOp = ARM_AM::ror;
1752       break;
1753   }
1754 
1755   if (ShOp == ARM_AM::ror && imm == 0)
1756     ShOp = ARM_AM::rrx;
1757 
1758   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1759     return MCDisassembler::Fail;
1760   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1761     return MCDisassembler::Fail;
1762   unsigned shift;
1763   if (U)
1764     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1765   else
1766     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1767   Inst.addOperand(MCOperand::createImm(shift));
1768 
1769   return S;
1770 }
1771 
1772 static DecodeStatus
1773 DecodeAddrMode3Instruction(MCInst &Inst, unsigned Insn,
1774                            uint64_t Address, const void *Decoder) {
1775   DecodeStatus S = MCDisassembler::Success;
1776 
1777   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
1778   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1779   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1780   unsigned type = fieldFromInstruction(Insn, 22, 1);
1781   unsigned imm = fieldFromInstruction(Insn, 8, 4);
1782   unsigned U = ((~fieldFromInstruction(Insn, 23, 1)) & 1) << 8;
1783   unsigned pred = fieldFromInstruction(Insn, 28, 4);
1784   unsigned W = fieldFromInstruction(Insn, 21, 1);
1785   unsigned P = fieldFromInstruction(Insn, 24, 1);
1786   unsigned Rt2 = Rt + 1;
1787 
1788   bool writeback = (W == 1) | (P == 0);
1789 
1790   // For {LD,ST}RD, Rt must be even, else undefined.
1791   switch (Inst.getOpcode()) {
1792     case ARM::STRD:
1793     case ARM::STRD_PRE:
1794     case ARM::STRD_POST:
1795     case ARM::LDRD:
1796     case ARM::LDRD_PRE:
1797     case ARM::LDRD_POST:
1798       if (Rt & 0x1) S = MCDisassembler::SoftFail;
1799       break;
1800     default:
1801       break;
1802   }
1803   switch (Inst.getOpcode()) {
1804     case ARM::STRD:
1805     case ARM::STRD_PRE:
1806     case ARM::STRD_POST:
1807       if (P == 0 && W == 1)
1808         S = MCDisassembler::SoftFail;
1809 
1810       if (writeback && (Rn == 15 || Rn == Rt || Rn == Rt2))
1811         S = MCDisassembler::SoftFail;
1812       if (type && Rm == 15)
1813         S = MCDisassembler::SoftFail;
1814       if (Rt2 == 15)
1815         S = MCDisassembler::SoftFail;
1816       if (!type && fieldFromInstruction(Insn, 8, 4))
1817         S = MCDisassembler::SoftFail;
1818       break;
1819     case ARM::STRH:
1820     case ARM::STRH_PRE:
1821     case ARM::STRH_POST:
1822       if (Rt == 15)
1823         S = MCDisassembler::SoftFail;
1824       if (writeback && (Rn == 15 || Rn == Rt))
1825         S = MCDisassembler::SoftFail;
1826       if (!type && Rm == 15)
1827         S = MCDisassembler::SoftFail;
1828       break;
1829     case ARM::LDRD:
1830     case ARM::LDRD_PRE:
1831     case ARM::LDRD_POST:
1832       if (type && Rn == 15) {
1833         if (Rt2 == 15)
1834           S = MCDisassembler::SoftFail;
1835         break;
1836       }
1837       if (P == 0 && W == 1)
1838         S = MCDisassembler::SoftFail;
1839       if (!type && (Rt2 == 15 || Rm == 15 || Rm == Rt || Rm == Rt2))
1840         S = MCDisassembler::SoftFail;
1841       if (!type && writeback && Rn == 15)
1842         S = MCDisassembler::SoftFail;
1843       if (writeback && (Rn == Rt || Rn == Rt2))
1844         S = MCDisassembler::SoftFail;
1845       break;
1846     case ARM::LDRH:
1847     case ARM::LDRH_PRE:
1848     case ARM::LDRH_POST:
1849       if (type && Rn == 15) {
1850         if (Rt == 15)
1851           S = MCDisassembler::SoftFail;
1852         break;
1853       }
1854       if (Rt == 15)
1855         S = MCDisassembler::SoftFail;
1856       if (!type && Rm == 15)
1857         S = MCDisassembler::SoftFail;
1858       if (!type && writeback && (Rn == 15 || Rn == Rt))
1859         S = MCDisassembler::SoftFail;
1860       break;
1861     case ARM::LDRSH:
1862     case ARM::LDRSH_PRE:
1863     case ARM::LDRSH_POST:
1864     case ARM::LDRSB:
1865     case ARM::LDRSB_PRE:
1866     case ARM::LDRSB_POST:
1867       if (type && Rn == 15) {
1868         if (Rt == 15)
1869           S = MCDisassembler::SoftFail;
1870         break;
1871       }
1872       if (type && (Rt == 15 || (writeback && Rn == Rt)))
1873         S = MCDisassembler::SoftFail;
1874       if (!type && (Rt == 15 || Rm == 15))
1875         S = MCDisassembler::SoftFail;
1876       if (!type && writeback && (Rn == 15 || Rn == Rt))
1877         S = MCDisassembler::SoftFail;
1878       break;
1879     default:
1880       break;
1881   }
1882 
1883   if (writeback) { // Writeback
1884     if (P)
1885       U |= ARMII::IndexModePre << 9;
1886     else
1887       U |= ARMII::IndexModePost << 9;
1888 
1889     // On stores, the writeback operand precedes Rt.
1890     switch (Inst.getOpcode()) {
1891     case ARM::STRD:
1892     case ARM::STRD_PRE:
1893     case ARM::STRD_POST:
1894     case ARM::STRH:
1895     case ARM::STRH_PRE:
1896     case ARM::STRH_POST:
1897       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1898         return MCDisassembler::Fail;
1899       break;
1900     default:
1901       break;
1902     }
1903   }
1904 
1905   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1906     return MCDisassembler::Fail;
1907   switch (Inst.getOpcode()) {
1908     case ARM::STRD:
1909     case ARM::STRD_PRE:
1910     case ARM::STRD_POST:
1911     case ARM::LDRD:
1912     case ARM::LDRD_PRE:
1913     case ARM::LDRD_POST:
1914       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
1915         return MCDisassembler::Fail;
1916       break;
1917     default:
1918       break;
1919   }
1920 
1921   if (writeback) {
1922     // On loads, the writeback operand comes after Rt.
1923     switch (Inst.getOpcode()) {
1924     case ARM::LDRD:
1925     case ARM::LDRD_PRE:
1926     case ARM::LDRD_POST:
1927     case ARM::LDRH:
1928     case ARM::LDRH_PRE:
1929     case ARM::LDRH_POST:
1930     case ARM::LDRSH:
1931     case ARM::LDRSH_PRE:
1932     case ARM::LDRSH_POST:
1933     case ARM::LDRSB:
1934     case ARM::LDRSB_PRE:
1935     case ARM::LDRSB_POST:
1936     case ARM::LDRHTr:
1937     case ARM::LDRSBTr:
1938       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1939         return MCDisassembler::Fail;
1940       break;
1941     default:
1942       break;
1943     }
1944   }
1945 
1946   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1947     return MCDisassembler::Fail;
1948 
1949   if (type) {
1950     Inst.addOperand(MCOperand::createReg(0));
1951     Inst.addOperand(MCOperand::createImm(U | (imm << 4) | Rm));
1952   } else {
1953     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1954     return MCDisassembler::Fail;
1955     Inst.addOperand(MCOperand::createImm(U));
1956   }
1957 
1958   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1959     return MCDisassembler::Fail;
1960 
1961   return S;
1962 }
1963 
1964 static DecodeStatus DecodeRFEInstruction(MCInst &Inst, unsigned Insn,
1965                                  uint64_t Address, const void *Decoder) {
1966   DecodeStatus S = MCDisassembler::Success;
1967 
1968   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
1969   unsigned mode = fieldFromInstruction(Insn, 23, 2);
1970 
1971   switch (mode) {
1972     case 0:
1973       mode = ARM_AM::da;
1974       break;
1975     case 1:
1976       mode = ARM_AM::ia;
1977       break;
1978     case 2:
1979       mode = ARM_AM::db;
1980       break;
1981     case 3:
1982       mode = ARM_AM::ib;
1983       break;
1984   }
1985 
1986   Inst.addOperand(MCOperand::createImm(mode));
1987   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1988     return MCDisassembler::Fail;
1989 
1990   return S;
1991 }
1992 
1993 static DecodeStatus DecodeQADDInstruction(MCInst &Inst, unsigned Insn,
1994                                uint64_t Address, const void *Decoder) {
1995   DecodeStatus S = MCDisassembler::Success;
1996 
1997   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
1998   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
1999   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2000   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2001 
2002   if (pred == 0xF)
2003     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2004 
2005   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2006     return MCDisassembler::Fail;
2007   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2008     return MCDisassembler::Fail;
2009   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2010     return MCDisassembler::Fail;
2011   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2012     return MCDisassembler::Fail;
2013   return S;
2014 }
2015 
2016 static DecodeStatus DecodeMemMultipleWritebackInstruction(MCInst &Inst,
2017                                   unsigned Insn,
2018                                   uint64_t Address, const void *Decoder) {
2019   DecodeStatus S = MCDisassembler::Success;
2020 
2021   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2022   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2023   unsigned reglist = fieldFromInstruction(Insn, 0, 16);
2024 
2025   if (pred == 0xF) {
2026     // Ambiguous with RFE and SRS
2027     switch (Inst.getOpcode()) {
2028       case ARM::LDMDA:
2029         Inst.setOpcode(ARM::RFEDA);
2030         break;
2031       case ARM::LDMDA_UPD:
2032         Inst.setOpcode(ARM::RFEDA_UPD);
2033         break;
2034       case ARM::LDMDB:
2035         Inst.setOpcode(ARM::RFEDB);
2036         break;
2037       case ARM::LDMDB_UPD:
2038         Inst.setOpcode(ARM::RFEDB_UPD);
2039         break;
2040       case ARM::LDMIA:
2041         Inst.setOpcode(ARM::RFEIA);
2042         break;
2043       case ARM::LDMIA_UPD:
2044         Inst.setOpcode(ARM::RFEIA_UPD);
2045         break;
2046       case ARM::LDMIB:
2047         Inst.setOpcode(ARM::RFEIB);
2048         break;
2049       case ARM::LDMIB_UPD:
2050         Inst.setOpcode(ARM::RFEIB_UPD);
2051         break;
2052       case ARM::STMDA:
2053         Inst.setOpcode(ARM::SRSDA);
2054         break;
2055       case ARM::STMDA_UPD:
2056         Inst.setOpcode(ARM::SRSDA_UPD);
2057         break;
2058       case ARM::STMDB:
2059         Inst.setOpcode(ARM::SRSDB);
2060         break;
2061       case ARM::STMDB_UPD:
2062         Inst.setOpcode(ARM::SRSDB_UPD);
2063         break;
2064       case ARM::STMIA:
2065         Inst.setOpcode(ARM::SRSIA);
2066         break;
2067       case ARM::STMIA_UPD:
2068         Inst.setOpcode(ARM::SRSIA_UPD);
2069         break;
2070       case ARM::STMIB:
2071         Inst.setOpcode(ARM::SRSIB);
2072         break;
2073       case ARM::STMIB_UPD:
2074         Inst.setOpcode(ARM::SRSIB_UPD);
2075         break;
2076       default:
2077         return MCDisassembler::Fail;
2078     }
2079 
2080     // For stores (which become SRS's, the only operand is the mode.
2081     if (fieldFromInstruction(Insn, 20, 1) == 0) {
2082       // Check SRS encoding constraints
2083       if (!(fieldFromInstruction(Insn, 22, 1) == 1 &&
2084             fieldFromInstruction(Insn, 20, 1) == 0))
2085         return MCDisassembler::Fail;
2086 
2087       Inst.addOperand(
2088           MCOperand::createImm(fieldFromInstruction(Insn, 0, 4)));
2089       return S;
2090     }
2091 
2092     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
2093   }
2094 
2095   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2096     return MCDisassembler::Fail;
2097   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2098     return MCDisassembler::Fail; // Tied
2099   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2100     return MCDisassembler::Fail;
2101   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
2102     return MCDisassembler::Fail;
2103 
2104   return S;
2105 }
2106 
2107 // Check for UNPREDICTABLE predicated ESB instruction
2108 static DecodeStatus DecodeHINTInstruction(MCInst &Inst, unsigned Insn,
2109                                  uint64_t Address, const void *Decoder) {
2110   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2111   unsigned imm8 = fieldFromInstruction(Insn, 0, 8);
2112   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2113   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2114 
2115   DecodeStatus S = MCDisassembler::Success;
2116 
2117   Inst.addOperand(MCOperand::createImm(imm8));
2118 
2119   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2120     return MCDisassembler::Fail;
2121 
2122   // ESB is unpredictable if pred != AL. Without the RAS extension, it is a NOP,
2123   // so all predicates should be allowed.
2124   if (imm8 == 0x10 && pred != 0xe && ((FeatureBits[ARM::FeatureRAS]) != 0))
2125     S = MCDisassembler::SoftFail;
2126 
2127   return S;
2128 }
2129 
2130 static DecodeStatus DecodeCPSInstruction(MCInst &Inst, unsigned Insn,
2131                                  uint64_t Address, const void *Decoder) {
2132   unsigned imod = fieldFromInstruction(Insn, 18, 2);
2133   unsigned M = fieldFromInstruction(Insn, 17, 1);
2134   unsigned iflags = fieldFromInstruction(Insn, 6, 3);
2135   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2136 
2137   DecodeStatus S = MCDisassembler::Success;
2138 
2139   // This decoder is called from multiple location that do not check
2140   // the full encoding is valid before they do.
2141   if (fieldFromInstruction(Insn, 5, 1) != 0 ||
2142       fieldFromInstruction(Insn, 16, 1) != 0 ||
2143       fieldFromInstruction(Insn, 20, 8) != 0x10)
2144     return MCDisassembler::Fail;
2145 
2146   // imod == '01' --> UNPREDICTABLE
2147   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2148   // return failure here.  The '01' imod value is unprintable, so there's
2149   // nothing useful we could do even if we returned UNPREDICTABLE.
2150 
2151   if (imod == 1) return MCDisassembler::Fail;
2152 
2153   if (imod && M) {
2154     Inst.setOpcode(ARM::CPS3p);
2155     Inst.addOperand(MCOperand::createImm(imod));
2156     Inst.addOperand(MCOperand::createImm(iflags));
2157     Inst.addOperand(MCOperand::createImm(mode));
2158   } else if (imod && !M) {
2159     Inst.setOpcode(ARM::CPS2p);
2160     Inst.addOperand(MCOperand::createImm(imod));
2161     Inst.addOperand(MCOperand::createImm(iflags));
2162     if (mode) S = MCDisassembler::SoftFail;
2163   } else if (!imod && M) {
2164     Inst.setOpcode(ARM::CPS1p);
2165     Inst.addOperand(MCOperand::createImm(mode));
2166     if (iflags) S = MCDisassembler::SoftFail;
2167   } else {
2168     // imod == '00' && M == '0' --> UNPREDICTABLE
2169     Inst.setOpcode(ARM::CPS1p);
2170     Inst.addOperand(MCOperand::createImm(mode));
2171     S = MCDisassembler::SoftFail;
2172   }
2173 
2174   return S;
2175 }
2176 
2177 static DecodeStatus DecodeT2CPSInstruction(MCInst &Inst, unsigned Insn,
2178                                  uint64_t Address, const void *Decoder) {
2179   unsigned imod = fieldFromInstruction(Insn, 9, 2);
2180   unsigned M = fieldFromInstruction(Insn, 8, 1);
2181   unsigned iflags = fieldFromInstruction(Insn, 5, 3);
2182   unsigned mode = fieldFromInstruction(Insn, 0, 5);
2183 
2184   DecodeStatus S = MCDisassembler::Success;
2185 
2186   // imod == '01' --> UNPREDICTABLE
2187   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
2188   // return failure here.  The '01' imod value is unprintable, so there's
2189   // nothing useful we could do even if we returned UNPREDICTABLE.
2190 
2191   if (imod == 1) return MCDisassembler::Fail;
2192 
2193   if (imod && M) {
2194     Inst.setOpcode(ARM::t2CPS3p);
2195     Inst.addOperand(MCOperand::createImm(imod));
2196     Inst.addOperand(MCOperand::createImm(iflags));
2197     Inst.addOperand(MCOperand::createImm(mode));
2198   } else if (imod && !M) {
2199     Inst.setOpcode(ARM::t2CPS2p);
2200     Inst.addOperand(MCOperand::createImm(imod));
2201     Inst.addOperand(MCOperand::createImm(iflags));
2202     if (mode) S = MCDisassembler::SoftFail;
2203   } else if (!imod && M) {
2204     Inst.setOpcode(ARM::t2CPS1p);
2205     Inst.addOperand(MCOperand::createImm(mode));
2206     if (iflags) S = MCDisassembler::SoftFail;
2207   } else {
2208     // imod == '00' && M == '0' --> this is a HINT instruction
2209     int imm = fieldFromInstruction(Insn, 0, 8);
2210     // HINT are defined only for immediate in [0..4]
2211     if(imm > 4) return MCDisassembler::Fail;
2212     Inst.setOpcode(ARM::t2HINT);
2213     Inst.addOperand(MCOperand::createImm(imm));
2214   }
2215 
2216   return S;
2217 }
2218 
2219 static DecodeStatus DecodeT2MOVTWInstruction(MCInst &Inst, unsigned Insn,
2220                                  uint64_t Address, const void *Decoder) {
2221   DecodeStatus S = MCDisassembler::Success;
2222 
2223   unsigned Rd = fieldFromInstruction(Insn, 8, 4);
2224   unsigned imm = 0;
2225 
2226   imm |= (fieldFromInstruction(Insn, 0, 8) << 0);
2227   imm |= (fieldFromInstruction(Insn, 12, 3) << 8);
2228   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2229   imm |= (fieldFromInstruction(Insn, 26, 1) << 11);
2230 
2231   if (Inst.getOpcode() == ARM::t2MOVTi16)
2232     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2233       return MCDisassembler::Fail;
2234   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
2235     return MCDisassembler::Fail;
2236 
2237   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2238     Inst.addOperand(MCOperand::createImm(imm));
2239 
2240   return S;
2241 }
2242 
2243 static DecodeStatus DecodeArmMOVTWInstruction(MCInst &Inst, unsigned Insn,
2244                                  uint64_t Address, const void *Decoder) {
2245   DecodeStatus S = MCDisassembler::Success;
2246 
2247   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2248   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2249   unsigned imm = 0;
2250 
2251   imm |= (fieldFromInstruction(Insn, 0, 12) << 0);
2252   imm |= (fieldFromInstruction(Insn, 16, 4) << 12);
2253 
2254   if (Inst.getOpcode() == ARM::MOVTi16)
2255     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2256       return MCDisassembler::Fail;
2257 
2258   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2259     return MCDisassembler::Fail;
2260 
2261   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
2262     Inst.addOperand(MCOperand::createImm(imm));
2263 
2264   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2265     return MCDisassembler::Fail;
2266 
2267   return S;
2268 }
2269 
2270 static DecodeStatus DecodeSMLAInstruction(MCInst &Inst, unsigned Insn,
2271                                  uint64_t Address, const void *Decoder) {
2272   DecodeStatus S = MCDisassembler::Success;
2273 
2274   unsigned Rd = fieldFromInstruction(Insn, 16, 4);
2275   unsigned Rn = fieldFromInstruction(Insn, 0, 4);
2276   unsigned Rm = fieldFromInstruction(Insn, 8, 4);
2277   unsigned Ra = fieldFromInstruction(Insn, 12, 4);
2278   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2279 
2280   if (pred == 0xF)
2281     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
2282 
2283   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
2284     return MCDisassembler::Fail;
2285   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2286     return MCDisassembler::Fail;
2287   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
2288     return MCDisassembler::Fail;
2289   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
2290     return MCDisassembler::Fail;
2291 
2292   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2293     return MCDisassembler::Fail;
2294 
2295   return S;
2296 }
2297 
2298 static DecodeStatus DecodeTSTInstruction(MCInst &Inst, unsigned Insn,
2299                                   uint64_t Address, const void *Decoder) {
2300   DecodeStatus S = MCDisassembler::Success;
2301 
2302   unsigned Pred = fieldFromInstruction(Insn, 28, 4);
2303   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2304   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2305 
2306   if (Pred == 0xF)
2307     return DecodeSETPANInstruction(Inst, Insn, Address, Decoder);
2308 
2309   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2310     return MCDisassembler::Fail;
2311   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2312     return MCDisassembler::Fail;
2313   if (!Check(S, DecodePredicateOperand(Inst, Pred, Address, Decoder)))
2314     return MCDisassembler::Fail;
2315 
2316   return S;
2317 }
2318 
2319 static DecodeStatus DecodeSETPANInstruction(MCInst &Inst, unsigned Insn,
2320                                   uint64_t Address, const void *Decoder) {
2321   DecodeStatus S = MCDisassembler::Success;
2322 
2323   unsigned Imm = fieldFromInstruction(Insn, 9, 1);
2324 
2325   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
2326   const FeatureBitset &FeatureBits = Dis->getSubtargetInfo().getFeatureBits();
2327 
2328   if (!FeatureBits[ARM::HasV8_1aOps] ||
2329       !FeatureBits[ARM::HasV8Ops])
2330     return MCDisassembler::Fail;
2331 
2332   // Decoder can be called from DecodeTST, which does not check the full
2333   // encoding is valid.
2334   if (fieldFromInstruction(Insn, 20,12) != 0xf11 ||
2335       fieldFromInstruction(Insn, 4,4) != 0)
2336     return MCDisassembler::Fail;
2337   if (fieldFromInstruction(Insn, 10,10) != 0 ||
2338       fieldFromInstruction(Insn, 0,4) != 0)
2339     S = MCDisassembler::SoftFail;
2340 
2341   Inst.setOpcode(ARM::SETPAN);
2342   Inst.addOperand(MCOperand::createImm(Imm));
2343 
2344   return S;
2345 }
2346 
2347 static DecodeStatus DecodeAddrModeImm12Operand(MCInst &Inst, unsigned Val,
2348                            uint64_t Address, const void *Decoder) {
2349   DecodeStatus S = MCDisassembler::Success;
2350 
2351   unsigned add = fieldFromInstruction(Val, 12, 1);
2352   unsigned imm = fieldFromInstruction(Val, 0, 12);
2353   unsigned Rn = fieldFromInstruction(Val, 13, 4);
2354 
2355   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2356     return MCDisassembler::Fail;
2357 
2358   if (!add) imm *= -1;
2359   if (imm == 0 && !add) imm = INT32_MIN;
2360   Inst.addOperand(MCOperand::createImm(imm));
2361   if (Rn == 15)
2362     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
2363 
2364   return S;
2365 }
2366 
2367 static DecodeStatus DecodeAddrMode5Operand(MCInst &Inst, unsigned Val,
2368                                    uint64_t Address, const void *Decoder) {
2369   DecodeStatus S = MCDisassembler::Success;
2370 
2371   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2372   // U == 1 to add imm, 0 to subtract it.
2373   unsigned U = fieldFromInstruction(Val, 8, 1);
2374   unsigned imm = fieldFromInstruction(Val, 0, 8);
2375 
2376   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2377     return MCDisassembler::Fail;
2378 
2379   if (U)
2380     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
2381   else
2382     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
2383 
2384   return S;
2385 }
2386 
2387 static DecodeStatus DecodeAddrMode5FP16Operand(MCInst &Inst, unsigned Val,
2388                                    uint64_t Address, const void *Decoder) {
2389   DecodeStatus S = MCDisassembler::Success;
2390 
2391   unsigned Rn = fieldFromInstruction(Val, 9, 4);
2392   // U == 1 to add imm, 0 to subtract it.
2393   unsigned U = fieldFromInstruction(Val, 8, 1);
2394   unsigned imm = fieldFromInstruction(Val, 0, 8);
2395 
2396   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2397     return MCDisassembler::Fail;
2398 
2399   if (U)
2400     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::add, imm)));
2401   else
2402     Inst.addOperand(MCOperand::createImm(ARM_AM::getAM5FP16Opc(ARM_AM::sub, imm)));
2403 
2404   return S;
2405 }
2406 
2407 static DecodeStatus DecodeAddrMode7Operand(MCInst &Inst, unsigned Val,
2408                                    uint64_t Address, const void *Decoder) {
2409   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
2410 }
2411 
2412 static DecodeStatus
2413 DecodeT2BInstruction(MCInst &Inst, unsigned Insn,
2414                      uint64_t Address, const void *Decoder) {
2415   DecodeStatus Status = MCDisassembler::Success;
2416 
2417   // Note the J1 and J2 values are from the encoded instruction.  So here
2418   // change them to I1 and I2 values via as documented:
2419   // I1 = NOT(J1 EOR S);
2420   // I2 = NOT(J2 EOR S);
2421   // and build the imm32 with one trailing zero as documented:
2422   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
2423   unsigned S = fieldFromInstruction(Insn, 26, 1);
2424   unsigned J1 = fieldFromInstruction(Insn, 13, 1);
2425   unsigned J2 = fieldFromInstruction(Insn, 11, 1);
2426   unsigned I1 = !(J1 ^ S);
2427   unsigned I2 = !(J2 ^ S);
2428   unsigned imm10 = fieldFromInstruction(Insn, 16, 10);
2429   unsigned imm11 = fieldFromInstruction(Insn, 0, 11);
2430   unsigned tmp = (S << 23) | (I1 << 22) | (I2 << 21) | (imm10 << 11) | imm11;
2431   int imm32 = SignExtend32<25>(tmp << 1);
2432   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
2433                                 true, 4, Inst, Decoder))
2434     Inst.addOperand(MCOperand::createImm(imm32));
2435 
2436   return Status;
2437 }
2438 
2439 static DecodeStatus
2440 DecodeBranchImmInstruction(MCInst &Inst, unsigned Insn,
2441                            uint64_t Address, const void *Decoder) {
2442   DecodeStatus S = MCDisassembler::Success;
2443 
2444   unsigned pred = fieldFromInstruction(Insn, 28, 4);
2445   unsigned imm = fieldFromInstruction(Insn, 0, 24) << 2;
2446 
2447   if (pred == 0xF) {
2448     Inst.setOpcode(ARM::BLXi);
2449     imm |= fieldFromInstruction(Insn, 24, 1) << 1;
2450     if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2451                                   true, 4, Inst, Decoder))
2452     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2453     return S;
2454   }
2455 
2456   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8,
2457                                 true, 4, Inst, Decoder))
2458     Inst.addOperand(MCOperand::createImm(SignExtend32<26>(imm)));
2459   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2460     return MCDisassembler::Fail;
2461 
2462   return S;
2463 }
2464 
2465 static DecodeStatus DecodeAddrMode6Operand(MCInst &Inst, unsigned Val,
2466                                    uint64_t Address, const void *Decoder) {
2467   DecodeStatus S = MCDisassembler::Success;
2468 
2469   unsigned Rm = fieldFromInstruction(Val, 0, 4);
2470   unsigned align = fieldFromInstruction(Val, 4, 2);
2471 
2472   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2473     return MCDisassembler::Fail;
2474   if (!align)
2475     Inst.addOperand(MCOperand::createImm(0));
2476   else
2477     Inst.addOperand(MCOperand::createImm(4 << align));
2478 
2479   return S;
2480 }
2481 
2482 static DecodeStatus DecodeVLDInstruction(MCInst &Inst, unsigned Insn,
2483                                    uint64_t Address, const void *Decoder) {
2484   DecodeStatus S = MCDisassembler::Success;
2485 
2486   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2487   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2488   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2489   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2490   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2491   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2492 
2493   // First output register
2494   switch (Inst.getOpcode()) {
2495   case ARM::VLD1q16: case ARM::VLD1q32: case ARM::VLD1q64: case ARM::VLD1q8:
2496   case ARM::VLD1q16wb_fixed: case ARM::VLD1q16wb_register:
2497   case ARM::VLD1q32wb_fixed: case ARM::VLD1q32wb_register:
2498   case ARM::VLD1q64wb_fixed: case ARM::VLD1q64wb_register:
2499   case ARM::VLD1q8wb_fixed: case ARM::VLD1q8wb_register:
2500   case ARM::VLD2d16: case ARM::VLD2d32: case ARM::VLD2d8:
2501   case ARM::VLD2d16wb_fixed: case ARM::VLD2d16wb_register:
2502   case ARM::VLD2d32wb_fixed: case ARM::VLD2d32wb_register:
2503   case ARM::VLD2d8wb_fixed: case ARM::VLD2d8wb_register:
2504     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2505       return MCDisassembler::Fail;
2506     break;
2507   case ARM::VLD2b16:
2508   case ARM::VLD2b32:
2509   case ARM::VLD2b8:
2510   case ARM::VLD2b16wb_fixed:
2511   case ARM::VLD2b16wb_register:
2512   case ARM::VLD2b32wb_fixed:
2513   case ARM::VLD2b32wb_register:
2514   case ARM::VLD2b8wb_fixed:
2515   case ARM::VLD2b8wb_register:
2516     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2517       return MCDisassembler::Fail;
2518     break;
2519   default:
2520     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2521       return MCDisassembler::Fail;
2522   }
2523 
2524   // Second output register
2525   switch (Inst.getOpcode()) {
2526     case ARM::VLD3d8:
2527     case ARM::VLD3d16:
2528     case ARM::VLD3d32:
2529     case ARM::VLD3d8_UPD:
2530     case ARM::VLD3d16_UPD:
2531     case ARM::VLD3d32_UPD:
2532     case ARM::VLD4d8:
2533     case ARM::VLD4d16:
2534     case ARM::VLD4d32:
2535     case ARM::VLD4d8_UPD:
2536     case ARM::VLD4d16_UPD:
2537     case ARM::VLD4d32_UPD:
2538       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2539         return MCDisassembler::Fail;
2540       break;
2541     case ARM::VLD3q8:
2542     case ARM::VLD3q16:
2543     case ARM::VLD3q32:
2544     case ARM::VLD3q8_UPD:
2545     case ARM::VLD3q16_UPD:
2546     case ARM::VLD3q32_UPD:
2547     case ARM::VLD4q8:
2548     case ARM::VLD4q16:
2549     case ARM::VLD4q32:
2550     case ARM::VLD4q8_UPD:
2551     case ARM::VLD4q16_UPD:
2552     case ARM::VLD4q32_UPD:
2553       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2554         return MCDisassembler::Fail;
2555       break;
2556     default:
2557       break;
2558   }
2559 
2560   // Third output register
2561   switch(Inst.getOpcode()) {
2562     case ARM::VLD3d8:
2563     case ARM::VLD3d16:
2564     case ARM::VLD3d32:
2565     case ARM::VLD3d8_UPD:
2566     case ARM::VLD3d16_UPD:
2567     case ARM::VLD3d32_UPD:
2568     case ARM::VLD4d8:
2569     case ARM::VLD4d16:
2570     case ARM::VLD4d32:
2571     case ARM::VLD4d8_UPD:
2572     case ARM::VLD4d16_UPD:
2573     case ARM::VLD4d32_UPD:
2574       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2575         return MCDisassembler::Fail;
2576       break;
2577     case ARM::VLD3q8:
2578     case ARM::VLD3q16:
2579     case ARM::VLD3q32:
2580     case ARM::VLD3q8_UPD:
2581     case ARM::VLD3q16_UPD:
2582     case ARM::VLD3q32_UPD:
2583     case ARM::VLD4q8:
2584     case ARM::VLD4q16:
2585     case ARM::VLD4q32:
2586     case ARM::VLD4q8_UPD:
2587     case ARM::VLD4q16_UPD:
2588     case ARM::VLD4q32_UPD:
2589       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2590         return MCDisassembler::Fail;
2591       break;
2592     default:
2593       break;
2594   }
2595 
2596   // Fourth output register
2597   switch (Inst.getOpcode()) {
2598     case ARM::VLD4d8:
2599     case ARM::VLD4d16:
2600     case ARM::VLD4d32:
2601     case ARM::VLD4d8_UPD:
2602     case ARM::VLD4d16_UPD:
2603     case ARM::VLD4d32_UPD:
2604       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2605         return MCDisassembler::Fail;
2606       break;
2607     case ARM::VLD4q8:
2608     case ARM::VLD4q16:
2609     case ARM::VLD4q32:
2610     case ARM::VLD4q8_UPD:
2611     case ARM::VLD4q16_UPD:
2612     case ARM::VLD4q32_UPD:
2613       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2614         return MCDisassembler::Fail;
2615       break;
2616     default:
2617       break;
2618   }
2619 
2620   // Writeback operand
2621   switch (Inst.getOpcode()) {
2622     case ARM::VLD1d8wb_fixed:
2623     case ARM::VLD1d16wb_fixed:
2624     case ARM::VLD1d32wb_fixed:
2625     case ARM::VLD1d64wb_fixed:
2626     case ARM::VLD1d8wb_register:
2627     case ARM::VLD1d16wb_register:
2628     case ARM::VLD1d32wb_register:
2629     case ARM::VLD1d64wb_register:
2630     case ARM::VLD1q8wb_fixed:
2631     case ARM::VLD1q16wb_fixed:
2632     case ARM::VLD1q32wb_fixed:
2633     case ARM::VLD1q64wb_fixed:
2634     case ARM::VLD1q8wb_register:
2635     case ARM::VLD1q16wb_register:
2636     case ARM::VLD1q32wb_register:
2637     case ARM::VLD1q64wb_register:
2638     case ARM::VLD1d8Twb_fixed:
2639     case ARM::VLD1d8Twb_register:
2640     case ARM::VLD1d16Twb_fixed:
2641     case ARM::VLD1d16Twb_register:
2642     case ARM::VLD1d32Twb_fixed:
2643     case ARM::VLD1d32Twb_register:
2644     case ARM::VLD1d64Twb_fixed:
2645     case ARM::VLD1d64Twb_register:
2646     case ARM::VLD1d8Qwb_fixed:
2647     case ARM::VLD1d8Qwb_register:
2648     case ARM::VLD1d16Qwb_fixed:
2649     case ARM::VLD1d16Qwb_register:
2650     case ARM::VLD1d32Qwb_fixed:
2651     case ARM::VLD1d32Qwb_register:
2652     case ARM::VLD1d64Qwb_fixed:
2653     case ARM::VLD1d64Qwb_register:
2654     case ARM::VLD2d8wb_fixed:
2655     case ARM::VLD2d16wb_fixed:
2656     case ARM::VLD2d32wb_fixed:
2657     case ARM::VLD2q8wb_fixed:
2658     case ARM::VLD2q16wb_fixed:
2659     case ARM::VLD2q32wb_fixed:
2660     case ARM::VLD2d8wb_register:
2661     case ARM::VLD2d16wb_register:
2662     case ARM::VLD2d32wb_register:
2663     case ARM::VLD2q8wb_register:
2664     case ARM::VLD2q16wb_register:
2665     case ARM::VLD2q32wb_register:
2666     case ARM::VLD2b8wb_fixed:
2667     case ARM::VLD2b16wb_fixed:
2668     case ARM::VLD2b32wb_fixed:
2669     case ARM::VLD2b8wb_register:
2670     case ARM::VLD2b16wb_register:
2671     case ARM::VLD2b32wb_register:
2672       Inst.addOperand(MCOperand::createImm(0));
2673       break;
2674     case ARM::VLD3d8_UPD:
2675     case ARM::VLD3d16_UPD:
2676     case ARM::VLD3d32_UPD:
2677     case ARM::VLD3q8_UPD:
2678     case ARM::VLD3q16_UPD:
2679     case ARM::VLD3q32_UPD:
2680     case ARM::VLD4d8_UPD:
2681     case ARM::VLD4d16_UPD:
2682     case ARM::VLD4d32_UPD:
2683     case ARM::VLD4q8_UPD:
2684     case ARM::VLD4q16_UPD:
2685     case ARM::VLD4q32_UPD:
2686       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2687         return MCDisassembler::Fail;
2688       break;
2689     default:
2690       break;
2691   }
2692 
2693   // AddrMode6 Base (register+alignment)
2694   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2695     return MCDisassembler::Fail;
2696 
2697   // AddrMode6 Offset (register)
2698   switch (Inst.getOpcode()) {
2699   default:
2700     // The below have been updated to have explicit am6offset split
2701     // between fixed and register offset. For those instructions not
2702     // yet updated, we need to add an additional reg0 operand for the
2703     // fixed variant.
2704     //
2705     // The fixed offset encodes as Rm == 0xd, so we check for that.
2706     if (Rm == 0xd) {
2707       Inst.addOperand(MCOperand::createReg(0));
2708       break;
2709     }
2710     // Fall through to handle the register offset variant.
2711     LLVM_FALLTHROUGH;
2712   case ARM::VLD1d8wb_fixed:
2713   case ARM::VLD1d16wb_fixed:
2714   case ARM::VLD1d32wb_fixed:
2715   case ARM::VLD1d64wb_fixed:
2716   case ARM::VLD1d8Twb_fixed:
2717   case ARM::VLD1d16Twb_fixed:
2718   case ARM::VLD1d32Twb_fixed:
2719   case ARM::VLD1d64Twb_fixed:
2720   case ARM::VLD1d8Qwb_fixed:
2721   case ARM::VLD1d16Qwb_fixed:
2722   case ARM::VLD1d32Qwb_fixed:
2723   case ARM::VLD1d64Qwb_fixed:
2724   case ARM::VLD1d8wb_register:
2725   case ARM::VLD1d16wb_register:
2726   case ARM::VLD1d32wb_register:
2727   case ARM::VLD1d64wb_register:
2728   case ARM::VLD1q8wb_fixed:
2729   case ARM::VLD1q16wb_fixed:
2730   case ARM::VLD1q32wb_fixed:
2731   case ARM::VLD1q64wb_fixed:
2732   case ARM::VLD1q8wb_register:
2733   case ARM::VLD1q16wb_register:
2734   case ARM::VLD1q32wb_register:
2735   case ARM::VLD1q64wb_register:
2736     // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
2737     // variant encodes Rm == 0xf. Anything else is a register offset post-
2738     // increment and we need to add the register operand to the instruction.
2739     if (Rm != 0xD && Rm != 0xF &&
2740         !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2741       return MCDisassembler::Fail;
2742     break;
2743   case ARM::VLD2d8wb_fixed:
2744   case ARM::VLD2d16wb_fixed:
2745   case ARM::VLD2d32wb_fixed:
2746   case ARM::VLD2b8wb_fixed:
2747   case ARM::VLD2b16wb_fixed:
2748   case ARM::VLD2b32wb_fixed:
2749   case ARM::VLD2q8wb_fixed:
2750   case ARM::VLD2q16wb_fixed:
2751   case ARM::VLD2q32wb_fixed:
2752     break;
2753   }
2754 
2755   return S;
2756 }
2757 
2758 static DecodeStatus DecodeVLDST1Instruction(MCInst &Inst, unsigned Insn,
2759                                    uint64_t Address, const void *Decoder) {
2760   unsigned type = fieldFromInstruction(Insn, 8, 4);
2761   unsigned align = fieldFromInstruction(Insn, 4, 2);
2762   if (type == 6 && (align & 2)) return MCDisassembler::Fail;
2763   if (type == 7 && (align & 2)) return MCDisassembler::Fail;
2764   if (type == 10 && align == 3) return MCDisassembler::Fail;
2765 
2766   unsigned load = fieldFromInstruction(Insn, 21, 1);
2767   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2768               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2769 }
2770 
2771 static DecodeStatus DecodeVLDST2Instruction(MCInst &Inst, unsigned Insn,
2772                                    uint64_t Address, const void *Decoder) {
2773   unsigned size = fieldFromInstruction(Insn, 6, 2);
2774   if (size == 3) return MCDisassembler::Fail;
2775 
2776   unsigned type = fieldFromInstruction(Insn, 8, 4);
2777   unsigned align = fieldFromInstruction(Insn, 4, 2);
2778   if (type == 8 && align == 3) return MCDisassembler::Fail;
2779   if (type == 9 && align == 3) return MCDisassembler::Fail;
2780 
2781   unsigned load = fieldFromInstruction(Insn, 21, 1);
2782   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2783               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2784 }
2785 
2786 static DecodeStatus DecodeVLDST3Instruction(MCInst &Inst, unsigned Insn,
2787                                    uint64_t Address, const void *Decoder) {
2788   unsigned size = fieldFromInstruction(Insn, 6, 2);
2789   if (size == 3) return MCDisassembler::Fail;
2790 
2791   unsigned align = fieldFromInstruction(Insn, 4, 2);
2792   if (align & 2) return MCDisassembler::Fail;
2793 
2794   unsigned load = fieldFromInstruction(Insn, 21, 1);
2795   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2796               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2797 }
2798 
2799 static DecodeStatus DecodeVLDST4Instruction(MCInst &Inst, unsigned Insn,
2800                                    uint64_t Address, const void *Decoder) {
2801   unsigned size = fieldFromInstruction(Insn, 6, 2);
2802   if (size == 3) return MCDisassembler::Fail;
2803 
2804   unsigned load = fieldFromInstruction(Insn, 21, 1);
2805   return load ? DecodeVLDInstruction(Inst, Insn, Address, Decoder)
2806               : DecodeVSTInstruction(Inst, Insn, Address, Decoder);
2807 }
2808 
2809 static DecodeStatus DecodeVSTInstruction(MCInst &Inst, unsigned Insn,
2810                                  uint64_t Address, const void *Decoder) {
2811   DecodeStatus S = MCDisassembler::Success;
2812 
2813   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
2814   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
2815   unsigned wb = fieldFromInstruction(Insn, 16, 4);
2816   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
2817   Rn |= fieldFromInstruction(Insn, 4, 2) << 4;
2818   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
2819 
2820   // Writeback Operand
2821   switch (Inst.getOpcode()) {
2822     case ARM::VST1d8wb_fixed:
2823     case ARM::VST1d16wb_fixed:
2824     case ARM::VST1d32wb_fixed:
2825     case ARM::VST1d64wb_fixed:
2826     case ARM::VST1d8wb_register:
2827     case ARM::VST1d16wb_register:
2828     case ARM::VST1d32wb_register:
2829     case ARM::VST1d64wb_register:
2830     case ARM::VST1q8wb_fixed:
2831     case ARM::VST1q16wb_fixed:
2832     case ARM::VST1q32wb_fixed:
2833     case ARM::VST1q64wb_fixed:
2834     case ARM::VST1q8wb_register:
2835     case ARM::VST1q16wb_register:
2836     case ARM::VST1q32wb_register:
2837     case ARM::VST1q64wb_register:
2838     case ARM::VST1d8Twb_fixed:
2839     case ARM::VST1d16Twb_fixed:
2840     case ARM::VST1d32Twb_fixed:
2841     case ARM::VST1d64Twb_fixed:
2842     case ARM::VST1d8Twb_register:
2843     case ARM::VST1d16Twb_register:
2844     case ARM::VST1d32Twb_register:
2845     case ARM::VST1d64Twb_register:
2846     case ARM::VST1d8Qwb_fixed:
2847     case ARM::VST1d16Qwb_fixed:
2848     case ARM::VST1d32Qwb_fixed:
2849     case ARM::VST1d64Qwb_fixed:
2850     case ARM::VST1d8Qwb_register:
2851     case ARM::VST1d16Qwb_register:
2852     case ARM::VST1d32Qwb_register:
2853     case ARM::VST1d64Qwb_register:
2854     case ARM::VST2d8wb_fixed:
2855     case ARM::VST2d16wb_fixed:
2856     case ARM::VST2d32wb_fixed:
2857     case ARM::VST2d8wb_register:
2858     case ARM::VST2d16wb_register:
2859     case ARM::VST2d32wb_register:
2860     case ARM::VST2q8wb_fixed:
2861     case ARM::VST2q16wb_fixed:
2862     case ARM::VST2q32wb_fixed:
2863     case ARM::VST2q8wb_register:
2864     case ARM::VST2q16wb_register:
2865     case ARM::VST2q32wb_register:
2866     case ARM::VST2b8wb_fixed:
2867     case ARM::VST2b16wb_fixed:
2868     case ARM::VST2b32wb_fixed:
2869     case ARM::VST2b8wb_register:
2870     case ARM::VST2b16wb_register:
2871     case ARM::VST2b32wb_register:
2872       if (Rm == 0xF)
2873         return MCDisassembler::Fail;
2874       Inst.addOperand(MCOperand::createImm(0));
2875       break;
2876     case ARM::VST3d8_UPD:
2877     case ARM::VST3d16_UPD:
2878     case ARM::VST3d32_UPD:
2879     case ARM::VST3q8_UPD:
2880     case ARM::VST3q16_UPD:
2881     case ARM::VST3q32_UPD:
2882     case ARM::VST4d8_UPD:
2883     case ARM::VST4d16_UPD:
2884     case ARM::VST4d32_UPD:
2885     case ARM::VST4q8_UPD:
2886     case ARM::VST4q16_UPD:
2887     case ARM::VST4q32_UPD:
2888       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2889         return MCDisassembler::Fail;
2890       break;
2891     default:
2892       break;
2893   }
2894 
2895   // AddrMode6 Base (register+alignment)
2896   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2897     return MCDisassembler::Fail;
2898 
2899   // AddrMode6 Offset (register)
2900   switch (Inst.getOpcode()) {
2901     default:
2902       if (Rm == 0xD)
2903         Inst.addOperand(MCOperand::createReg(0));
2904       else if (Rm != 0xF) {
2905         if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2906           return MCDisassembler::Fail;
2907       }
2908       break;
2909     case ARM::VST1d8wb_fixed:
2910     case ARM::VST1d16wb_fixed:
2911     case ARM::VST1d32wb_fixed:
2912     case ARM::VST1d64wb_fixed:
2913     case ARM::VST1q8wb_fixed:
2914     case ARM::VST1q16wb_fixed:
2915     case ARM::VST1q32wb_fixed:
2916     case ARM::VST1q64wb_fixed:
2917     case ARM::VST1d8Twb_fixed:
2918     case ARM::VST1d16Twb_fixed:
2919     case ARM::VST1d32Twb_fixed:
2920     case ARM::VST1d64Twb_fixed:
2921     case ARM::VST1d8Qwb_fixed:
2922     case ARM::VST1d16Qwb_fixed:
2923     case ARM::VST1d32Qwb_fixed:
2924     case ARM::VST1d64Qwb_fixed:
2925     case ARM::VST2d8wb_fixed:
2926     case ARM::VST2d16wb_fixed:
2927     case ARM::VST2d32wb_fixed:
2928     case ARM::VST2q8wb_fixed:
2929     case ARM::VST2q16wb_fixed:
2930     case ARM::VST2q32wb_fixed:
2931     case ARM::VST2b8wb_fixed:
2932     case ARM::VST2b16wb_fixed:
2933     case ARM::VST2b32wb_fixed:
2934       break;
2935   }
2936 
2937   // First input register
2938   switch (Inst.getOpcode()) {
2939   case ARM::VST1q16:
2940   case ARM::VST1q32:
2941   case ARM::VST1q64:
2942   case ARM::VST1q8:
2943   case ARM::VST1q16wb_fixed:
2944   case ARM::VST1q16wb_register:
2945   case ARM::VST1q32wb_fixed:
2946   case ARM::VST1q32wb_register:
2947   case ARM::VST1q64wb_fixed:
2948   case ARM::VST1q64wb_register:
2949   case ARM::VST1q8wb_fixed:
2950   case ARM::VST1q8wb_register:
2951   case ARM::VST2d16:
2952   case ARM::VST2d32:
2953   case ARM::VST2d8:
2954   case ARM::VST2d16wb_fixed:
2955   case ARM::VST2d16wb_register:
2956   case ARM::VST2d32wb_fixed:
2957   case ARM::VST2d32wb_register:
2958   case ARM::VST2d8wb_fixed:
2959   case ARM::VST2d8wb_register:
2960     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
2961       return MCDisassembler::Fail;
2962     break;
2963   case ARM::VST2b16:
2964   case ARM::VST2b32:
2965   case ARM::VST2b8:
2966   case ARM::VST2b16wb_fixed:
2967   case ARM::VST2b16wb_register:
2968   case ARM::VST2b32wb_fixed:
2969   case ARM::VST2b32wb_register:
2970   case ARM::VST2b8wb_fixed:
2971   case ARM::VST2b8wb_register:
2972     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
2973       return MCDisassembler::Fail;
2974     break;
2975   default:
2976     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2977       return MCDisassembler::Fail;
2978   }
2979 
2980   // Second input register
2981   switch (Inst.getOpcode()) {
2982     case ARM::VST3d8:
2983     case ARM::VST3d16:
2984     case ARM::VST3d32:
2985     case ARM::VST3d8_UPD:
2986     case ARM::VST3d16_UPD:
2987     case ARM::VST3d32_UPD:
2988     case ARM::VST4d8:
2989     case ARM::VST4d16:
2990     case ARM::VST4d32:
2991     case ARM::VST4d8_UPD:
2992     case ARM::VST4d16_UPD:
2993     case ARM::VST4d32_UPD:
2994       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2995         return MCDisassembler::Fail;
2996       break;
2997     case ARM::VST3q8:
2998     case ARM::VST3q16:
2999     case ARM::VST3q32:
3000     case ARM::VST3q8_UPD:
3001     case ARM::VST3q16_UPD:
3002     case ARM::VST3q32_UPD:
3003     case ARM::VST4q8:
3004     case ARM::VST4q16:
3005     case ARM::VST4q32:
3006     case ARM::VST4q8_UPD:
3007     case ARM::VST4q16_UPD:
3008     case ARM::VST4q32_UPD:
3009       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3010         return MCDisassembler::Fail;
3011       break;
3012     default:
3013       break;
3014   }
3015 
3016   // Third input register
3017   switch (Inst.getOpcode()) {
3018     case ARM::VST3d8:
3019     case ARM::VST3d16:
3020     case ARM::VST3d32:
3021     case ARM::VST3d8_UPD:
3022     case ARM::VST3d16_UPD:
3023     case ARM::VST3d32_UPD:
3024     case ARM::VST4d8:
3025     case ARM::VST4d16:
3026     case ARM::VST4d32:
3027     case ARM::VST4d8_UPD:
3028     case ARM::VST4d16_UPD:
3029     case ARM::VST4d32_UPD:
3030       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
3031         return MCDisassembler::Fail;
3032       break;
3033     case ARM::VST3q8:
3034     case ARM::VST3q16:
3035     case ARM::VST3q32:
3036     case ARM::VST3q8_UPD:
3037     case ARM::VST3q16_UPD:
3038     case ARM::VST3q32_UPD:
3039     case ARM::VST4q8:
3040     case ARM::VST4q16:
3041     case ARM::VST4q32:
3042     case ARM::VST4q8_UPD:
3043     case ARM::VST4q16_UPD:
3044     case ARM::VST4q32_UPD:
3045       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
3046         return MCDisassembler::Fail;
3047       break;
3048     default:
3049       break;
3050   }
3051 
3052   // Fourth input register
3053   switch (Inst.getOpcode()) {
3054     case ARM::VST4d8:
3055     case ARM::VST4d16:
3056     case ARM::VST4d32:
3057     case ARM::VST4d8_UPD:
3058     case ARM::VST4d16_UPD:
3059     case ARM::VST4d32_UPD:
3060       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
3061         return MCDisassembler::Fail;
3062       break;
3063     case ARM::VST4q8:
3064     case ARM::VST4q16:
3065     case ARM::VST4q32:
3066     case ARM::VST4q8_UPD:
3067     case ARM::VST4q16_UPD:
3068     case ARM::VST4q32_UPD:
3069       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
3070         return MCDisassembler::Fail;
3071       break;
3072     default:
3073       break;
3074   }
3075 
3076   return S;
3077 }
3078 
3079 static DecodeStatus DecodeVLD1DupInstruction(MCInst &Inst, unsigned Insn,
3080                                     uint64_t Address, const void *Decoder) {
3081   DecodeStatus S = MCDisassembler::Success;
3082 
3083   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3084   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3085   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3086   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3087   unsigned align = fieldFromInstruction(Insn, 4, 1);
3088   unsigned size = fieldFromInstruction(Insn, 6, 2);
3089 
3090   if (size == 0 && align == 1)
3091     return MCDisassembler::Fail;
3092   align *= (1 << size);
3093 
3094   switch (Inst.getOpcode()) {
3095   case ARM::VLD1DUPq16: case ARM::VLD1DUPq32: case ARM::VLD1DUPq8:
3096   case ARM::VLD1DUPq16wb_fixed: case ARM::VLD1DUPq16wb_register:
3097   case ARM::VLD1DUPq32wb_fixed: case ARM::VLD1DUPq32wb_register:
3098   case ARM::VLD1DUPq8wb_fixed: case ARM::VLD1DUPq8wb_register:
3099     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3100       return MCDisassembler::Fail;
3101     break;
3102   default:
3103     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3104       return MCDisassembler::Fail;
3105     break;
3106   }
3107   if (Rm != 0xF) {
3108     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3109       return MCDisassembler::Fail;
3110   }
3111 
3112   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3113     return MCDisassembler::Fail;
3114   Inst.addOperand(MCOperand::createImm(align));
3115 
3116   // The fixed offset post-increment encodes Rm == 0xd. The no-writeback
3117   // variant encodes Rm == 0xf. Anything else is a register offset post-
3118   // increment and we need to add the register operand to the instruction.
3119   if (Rm != 0xD && Rm != 0xF &&
3120       !Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3121     return MCDisassembler::Fail;
3122 
3123   return S;
3124 }
3125 
3126 static DecodeStatus DecodeVLD2DupInstruction(MCInst &Inst, unsigned Insn,
3127                                     uint64_t Address, const void *Decoder) {
3128   DecodeStatus S = MCDisassembler::Success;
3129 
3130   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3131   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3132   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3133   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3134   unsigned align = fieldFromInstruction(Insn, 4, 1);
3135   unsigned size = 1 << fieldFromInstruction(Insn, 6, 2);
3136   align *= 2*size;
3137 
3138   switch (Inst.getOpcode()) {
3139   case ARM::VLD2DUPd16: case ARM::VLD2DUPd32: case ARM::VLD2DUPd8:
3140   case ARM::VLD2DUPd16wb_fixed: case ARM::VLD2DUPd16wb_register:
3141   case ARM::VLD2DUPd32wb_fixed: case ARM::VLD2DUPd32wb_register:
3142   case ARM::VLD2DUPd8wb_fixed: case ARM::VLD2DUPd8wb_register:
3143     if (!Check(S, DecodeDPairRegisterClass(Inst, Rd, Address, Decoder)))
3144       return MCDisassembler::Fail;
3145     break;
3146   case ARM::VLD2DUPd16x2: case ARM::VLD2DUPd32x2: case ARM::VLD2DUPd8x2:
3147   case ARM::VLD2DUPd16x2wb_fixed: case ARM::VLD2DUPd16x2wb_register:
3148   case ARM::VLD2DUPd32x2wb_fixed: case ARM::VLD2DUPd32x2wb_register:
3149   case ARM::VLD2DUPd8x2wb_fixed: case ARM::VLD2DUPd8x2wb_register:
3150     if (!Check(S, DecodeDPairSpacedRegisterClass(Inst, Rd, Address, Decoder)))
3151       return MCDisassembler::Fail;
3152     break;
3153   default:
3154     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3155       return MCDisassembler::Fail;
3156     break;
3157   }
3158 
3159   if (Rm != 0xF)
3160     Inst.addOperand(MCOperand::createImm(0));
3161 
3162   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3163     return MCDisassembler::Fail;
3164   Inst.addOperand(MCOperand::createImm(align));
3165 
3166   if (Rm != 0xD && Rm != 0xF) {
3167     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3168       return MCDisassembler::Fail;
3169   }
3170 
3171   return S;
3172 }
3173 
3174 static DecodeStatus DecodeVLD3DupInstruction(MCInst &Inst, unsigned Insn,
3175                                     uint64_t Address, const void *Decoder) {
3176   DecodeStatus S = MCDisassembler::Success;
3177 
3178   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3179   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3180   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3181   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3182   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3183 
3184   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3185     return MCDisassembler::Fail;
3186   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3187     return MCDisassembler::Fail;
3188   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3189     return MCDisassembler::Fail;
3190   if (Rm != 0xF) {
3191     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3192       return MCDisassembler::Fail;
3193   }
3194 
3195   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3196     return MCDisassembler::Fail;
3197   Inst.addOperand(MCOperand::createImm(0));
3198 
3199   if (Rm == 0xD)
3200     Inst.addOperand(MCOperand::createReg(0));
3201   else if (Rm != 0xF) {
3202     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3203       return MCDisassembler::Fail;
3204   }
3205 
3206   return S;
3207 }
3208 
3209 static DecodeStatus DecodeVLD4DupInstruction(MCInst &Inst, unsigned Insn,
3210                                     uint64_t Address, const void *Decoder) {
3211   DecodeStatus S = MCDisassembler::Success;
3212 
3213   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3214   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3215   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3216   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3217   unsigned size = fieldFromInstruction(Insn, 6, 2);
3218   unsigned inc = fieldFromInstruction(Insn, 5, 1) + 1;
3219   unsigned align = fieldFromInstruction(Insn, 4, 1);
3220 
3221   if (size == 0x3) {
3222     if (align == 0)
3223       return MCDisassembler::Fail;
3224     align = 16;
3225   } else {
3226     if (size == 2) {
3227       align *= 8;
3228     } else {
3229       size = 1 << size;
3230       align *= 4*size;
3231     }
3232   }
3233 
3234   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3235     return MCDisassembler::Fail;
3236   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
3237     return MCDisassembler::Fail;
3238   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
3239     return MCDisassembler::Fail;
3240   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
3241     return MCDisassembler::Fail;
3242   if (Rm != 0xF) {
3243     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3244       return MCDisassembler::Fail;
3245   }
3246 
3247   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3248     return MCDisassembler::Fail;
3249   Inst.addOperand(MCOperand::createImm(align));
3250 
3251   if (Rm == 0xD)
3252     Inst.addOperand(MCOperand::createReg(0));
3253   else if (Rm != 0xF) {
3254     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3255       return MCDisassembler::Fail;
3256   }
3257 
3258   return S;
3259 }
3260 
3261 static DecodeStatus
3262 DecodeNEONModImmInstruction(MCInst &Inst, unsigned Insn,
3263                             uint64_t Address, const void *Decoder) {
3264   DecodeStatus S = MCDisassembler::Success;
3265 
3266   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3267   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3268   unsigned imm = fieldFromInstruction(Insn, 0, 4);
3269   imm |= fieldFromInstruction(Insn, 16, 3) << 4;
3270   imm |= fieldFromInstruction(Insn, 24, 1) << 7;
3271   imm |= fieldFromInstruction(Insn, 8, 4) << 8;
3272   imm |= fieldFromInstruction(Insn, 5, 1) << 12;
3273   unsigned Q = fieldFromInstruction(Insn, 6, 1);
3274 
3275   if (Q) {
3276     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3277     return MCDisassembler::Fail;
3278   } else {
3279     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3280     return MCDisassembler::Fail;
3281   }
3282 
3283   Inst.addOperand(MCOperand::createImm(imm));
3284 
3285   switch (Inst.getOpcode()) {
3286     case ARM::VORRiv4i16:
3287     case ARM::VORRiv2i32:
3288     case ARM::VBICiv4i16:
3289     case ARM::VBICiv2i32:
3290       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3291         return MCDisassembler::Fail;
3292       break;
3293     case ARM::VORRiv8i16:
3294     case ARM::VORRiv4i32:
3295     case ARM::VBICiv8i16:
3296     case ARM::VBICiv4i32:
3297       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3298         return MCDisassembler::Fail;
3299       break;
3300     default:
3301       break;
3302   }
3303 
3304   return S;
3305 }
3306 
3307 static DecodeStatus DecodeVSHLMaxInstruction(MCInst &Inst, unsigned Insn,
3308                                         uint64_t Address, const void *Decoder) {
3309   DecodeStatus S = MCDisassembler::Success;
3310 
3311   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3312   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3313   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3314   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3315   unsigned size = fieldFromInstruction(Insn, 18, 2);
3316 
3317   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
3318     return MCDisassembler::Fail;
3319   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3320     return MCDisassembler::Fail;
3321   Inst.addOperand(MCOperand::createImm(8 << size));
3322 
3323   return S;
3324 }
3325 
3326 static DecodeStatus DecodeShiftRight8Imm(MCInst &Inst, unsigned Val,
3327                                uint64_t Address, const void *Decoder) {
3328   Inst.addOperand(MCOperand::createImm(8 - Val));
3329   return MCDisassembler::Success;
3330 }
3331 
3332 static DecodeStatus DecodeShiftRight16Imm(MCInst &Inst, unsigned Val,
3333                                uint64_t Address, const void *Decoder) {
3334   Inst.addOperand(MCOperand::createImm(16 - Val));
3335   return MCDisassembler::Success;
3336 }
3337 
3338 static DecodeStatus DecodeShiftRight32Imm(MCInst &Inst, unsigned Val,
3339                                uint64_t Address, const void *Decoder) {
3340   Inst.addOperand(MCOperand::createImm(32 - Val));
3341   return MCDisassembler::Success;
3342 }
3343 
3344 static DecodeStatus DecodeShiftRight64Imm(MCInst &Inst, unsigned Val,
3345                                uint64_t Address, const void *Decoder) {
3346   Inst.addOperand(MCOperand::createImm(64 - Val));
3347   return MCDisassembler::Success;
3348 }
3349 
3350 static DecodeStatus DecodeTBLInstruction(MCInst &Inst, unsigned Insn,
3351                                uint64_t Address, const void *Decoder) {
3352   DecodeStatus S = MCDisassembler::Success;
3353 
3354   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
3355   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
3356   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3357   Rn |= fieldFromInstruction(Insn, 7, 1) << 4;
3358   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
3359   Rm |= fieldFromInstruction(Insn, 5, 1) << 4;
3360   unsigned op = fieldFromInstruction(Insn, 6, 1);
3361 
3362   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3363     return MCDisassembler::Fail;
3364   if (op) {
3365     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3366     return MCDisassembler::Fail; // Writeback
3367   }
3368 
3369   switch (Inst.getOpcode()) {
3370   case ARM::VTBL2:
3371   case ARM::VTBX2:
3372     if (!Check(S, DecodeDPairRegisterClass(Inst, Rn, Address, Decoder)))
3373       return MCDisassembler::Fail;
3374     break;
3375   default:
3376     if (!Check(S, DecodeDPRRegisterClass(Inst, Rn, Address, Decoder)))
3377       return MCDisassembler::Fail;
3378   }
3379 
3380   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
3381     return MCDisassembler::Fail;
3382 
3383   return S;
3384 }
3385 
3386 static DecodeStatus DecodeThumbAddSpecialReg(MCInst &Inst, uint16_t Insn,
3387                                      uint64_t Address, const void *Decoder) {
3388   DecodeStatus S = MCDisassembler::Success;
3389 
3390   unsigned dst = fieldFromInstruction(Insn, 8, 3);
3391   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3392 
3393   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
3394     return MCDisassembler::Fail;
3395 
3396   switch(Inst.getOpcode()) {
3397     default:
3398       return MCDisassembler::Fail;
3399     case ARM::tADR:
3400       break; // tADR does not explicitly represent the PC as an operand.
3401     case ARM::tADDrSPi:
3402       Inst.addOperand(MCOperand::createReg(ARM::SP));
3403       break;
3404   }
3405 
3406   Inst.addOperand(MCOperand::createImm(imm));
3407   return S;
3408 }
3409 
3410 static DecodeStatus DecodeThumbBROperand(MCInst &Inst, unsigned Val,
3411                                  uint64_t Address, const void *Decoder) {
3412   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<12>(Val<<1) + 4,
3413                                 true, 2, Inst, Decoder))
3414     Inst.addOperand(MCOperand::createImm(SignExtend32<12>(Val << 1)));
3415   return MCDisassembler::Success;
3416 }
3417 
3418 static DecodeStatus DecodeT2BROperand(MCInst &Inst, unsigned Val,
3419                                  uint64_t Address, const void *Decoder) {
3420   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<21>(Val) + 4,
3421                                 true, 4, Inst, Decoder))
3422     Inst.addOperand(MCOperand::createImm(SignExtend32<21>(Val)));
3423   return MCDisassembler::Success;
3424 }
3425 
3426 static DecodeStatus DecodeThumbCmpBROperand(MCInst &Inst, unsigned Val,
3427                                  uint64_t Address, const void *Decoder) {
3428   if (!tryAddingSymbolicOperand(Address, Address + (Val<<1) + 4,
3429                                 true, 2, Inst, Decoder))
3430     Inst.addOperand(MCOperand::createImm(Val << 1));
3431   return MCDisassembler::Success;
3432 }
3433 
3434 static DecodeStatus DecodeThumbAddrModeRR(MCInst &Inst, unsigned Val,
3435                                  uint64_t Address, const void *Decoder) {
3436   DecodeStatus S = MCDisassembler::Success;
3437 
3438   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3439   unsigned Rm = fieldFromInstruction(Val, 3, 3);
3440 
3441   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3442     return MCDisassembler::Fail;
3443   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
3444     return MCDisassembler::Fail;
3445 
3446   return S;
3447 }
3448 
3449 static DecodeStatus DecodeThumbAddrModeIS(MCInst &Inst, unsigned Val,
3450                                   uint64_t Address, const void *Decoder) {
3451   DecodeStatus S = MCDisassembler::Success;
3452 
3453   unsigned Rn = fieldFromInstruction(Val, 0, 3);
3454   unsigned imm = fieldFromInstruction(Val, 3, 5);
3455 
3456   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
3457     return MCDisassembler::Fail;
3458   Inst.addOperand(MCOperand::createImm(imm));
3459 
3460   return S;
3461 }
3462 
3463 static DecodeStatus DecodeThumbAddrModePC(MCInst &Inst, unsigned Val,
3464                                   uint64_t Address, const void *Decoder) {
3465   unsigned imm = Val << 2;
3466 
3467   Inst.addOperand(MCOperand::createImm(imm));
3468   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
3469 
3470   return MCDisassembler::Success;
3471 }
3472 
3473 static DecodeStatus DecodeThumbAddrModeSP(MCInst &Inst, unsigned Val,
3474                                   uint64_t Address, const void *Decoder) {
3475   Inst.addOperand(MCOperand::createReg(ARM::SP));
3476   Inst.addOperand(MCOperand::createImm(Val));
3477 
3478   return MCDisassembler::Success;
3479 }
3480 
3481 static DecodeStatus DecodeT2AddrModeSOReg(MCInst &Inst, unsigned Val,
3482                                   uint64_t Address, const void *Decoder) {
3483   DecodeStatus S = MCDisassembler::Success;
3484 
3485   unsigned Rn = fieldFromInstruction(Val, 6, 4);
3486   unsigned Rm = fieldFromInstruction(Val, 2, 4);
3487   unsigned imm = fieldFromInstruction(Val, 0, 2);
3488 
3489   // Thumb stores cannot use PC as dest register.
3490   switch (Inst.getOpcode()) {
3491   case ARM::t2STRHs:
3492   case ARM::t2STRBs:
3493   case ARM::t2STRs:
3494     if (Rn == 15)
3495       return MCDisassembler::Fail;
3496     break;
3497   default:
3498     break;
3499   }
3500 
3501   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3502     return MCDisassembler::Fail;
3503   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3504     return MCDisassembler::Fail;
3505   Inst.addOperand(MCOperand::createImm(imm));
3506 
3507   return S;
3508 }
3509 
3510 static DecodeStatus DecodeT2LoadShift(MCInst &Inst, unsigned Insn,
3511                               uint64_t Address, const void *Decoder) {
3512   DecodeStatus S = MCDisassembler::Success;
3513 
3514   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3515   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3516 
3517   const FeatureBitset &featureBits =
3518     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3519 
3520   bool hasMP = featureBits[ARM::FeatureMP];
3521   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3522 
3523   if (Rn == 15) {
3524     switch (Inst.getOpcode()) {
3525     case ARM::t2LDRBs:
3526       Inst.setOpcode(ARM::t2LDRBpci);
3527       break;
3528     case ARM::t2LDRHs:
3529       Inst.setOpcode(ARM::t2LDRHpci);
3530       break;
3531     case ARM::t2LDRSHs:
3532       Inst.setOpcode(ARM::t2LDRSHpci);
3533       break;
3534     case ARM::t2LDRSBs:
3535       Inst.setOpcode(ARM::t2LDRSBpci);
3536       break;
3537     case ARM::t2LDRs:
3538       Inst.setOpcode(ARM::t2LDRpci);
3539       break;
3540     case ARM::t2PLDs:
3541       Inst.setOpcode(ARM::t2PLDpci);
3542       break;
3543     case ARM::t2PLIs:
3544       Inst.setOpcode(ARM::t2PLIpci);
3545       break;
3546     default:
3547       return MCDisassembler::Fail;
3548     }
3549 
3550     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3551   }
3552 
3553   if (Rt == 15) {
3554     switch (Inst.getOpcode()) {
3555     case ARM::t2LDRSHs:
3556       return MCDisassembler::Fail;
3557     case ARM::t2LDRHs:
3558       Inst.setOpcode(ARM::t2PLDWs);
3559       break;
3560     case ARM::t2LDRSBs:
3561       Inst.setOpcode(ARM::t2PLIs);
3562       break;
3563     default:
3564       break;
3565     }
3566   }
3567 
3568   switch (Inst.getOpcode()) {
3569     case ARM::t2PLDs:
3570       break;
3571     case ARM::t2PLIs:
3572       if (!hasV7Ops)
3573         return MCDisassembler::Fail;
3574       break;
3575     case ARM::t2PLDWs:
3576       if (!hasV7Ops || !hasMP)
3577         return MCDisassembler::Fail;
3578       break;
3579     default:
3580       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3581         return MCDisassembler::Fail;
3582   }
3583 
3584   unsigned addrmode = fieldFromInstruction(Insn, 4, 2);
3585   addrmode |= fieldFromInstruction(Insn, 0, 4) << 2;
3586   addrmode |= fieldFromInstruction(Insn, 16, 4) << 6;
3587   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
3588     return MCDisassembler::Fail;
3589 
3590   return S;
3591 }
3592 
3593 static DecodeStatus DecodeT2LoadImm8(MCInst &Inst, unsigned Insn,
3594                                 uint64_t Address, const void* Decoder) {
3595   DecodeStatus S = MCDisassembler::Success;
3596 
3597   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3598   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3599   unsigned U = fieldFromInstruction(Insn, 9, 1);
3600   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3601   imm |= (U << 8);
3602   imm |= (Rn << 9);
3603   unsigned add = fieldFromInstruction(Insn, 9, 1);
3604 
3605   const FeatureBitset &featureBits =
3606     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3607 
3608   bool hasMP = featureBits[ARM::FeatureMP];
3609   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3610 
3611   if (Rn == 15) {
3612     switch (Inst.getOpcode()) {
3613     case ARM::t2LDRi8:
3614       Inst.setOpcode(ARM::t2LDRpci);
3615       break;
3616     case ARM::t2LDRBi8:
3617       Inst.setOpcode(ARM::t2LDRBpci);
3618       break;
3619     case ARM::t2LDRSBi8:
3620       Inst.setOpcode(ARM::t2LDRSBpci);
3621       break;
3622     case ARM::t2LDRHi8:
3623       Inst.setOpcode(ARM::t2LDRHpci);
3624       break;
3625     case ARM::t2LDRSHi8:
3626       Inst.setOpcode(ARM::t2LDRSHpci);
3627       break;
3628     case ARM::t2PLDi8:
3629       Inst.setOpcode(ARM::t2PLDpci);
3630       break;
3631     case ARM::t2PLIi8:
3632       Inst.setOpcode(ARM::t2PLIpci);
3633       break;
3634     default:
3635       return MCDisassembler::Fail;
3636     }
3637     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3638   }
3639 
3640   if (Rt == 15) {
3641     switch (Inst.getOpcode()) {
3642     case ARM::t2LDRSHi8:
3643       return MCDisassembler::Fail;
3644     case ARM::t2LDRHi8:
3645       if (!add)
3646         Inst.setOpcode(ARM::t2PLDWi8);
3647       break;
3648     case ARM::t2LDRSBi8:
3649       Inst.setOpcode(ARM::t2PLIi8);
3650       break;
3651     default:
3652       break;
3653     }
3654   }
3655 
3656   switch (Inst.getOpcode()) {
3657   case ARM::t2PLDi8:
3658     break;
3659   case ARM::t2PLIi8:
3660     if (!hasV7Ops)
3661       return MCDisassembler::Fail;
3662     break;
3663   case ARM::t2PLDWi8:
3664       if (!hasV7Ops || !hasMP)
3665         return MCDisassembler::Fail;
3666       break;
3667   default:
3668     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3669       return MCDisassembler::Fail;
3670   }
3671 
3672   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3673     return MCDisassembler::Fail;
3674   return S;
3675 }
3676 
3677 static DecodeStatus DecodeT2LoadImm12(MCInst &Inst, unsigned Insn,
3678                                 uint64_t Address, const void* Decoder) {
3679   DecodeStatus S = MCDisassembler::Success;
3680 
3681   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3682   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3683   unsigned imm = fieldFromInstruction(Insn, 0, 12);
3684   imm |= (Rn << 13);
3685 
3686   const FeatureBitset &featureBits =
3687     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3688 
3689   bool hasMP = featureBits[ARM::FeatureMP];
3690   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3691 
3692   if (Rn == 15) {
3693     switch (Inst.getOpcode()) {
3694     case ARM::t2LDRi12:
3695       Inst.setOpcode(ARM::t2LDRpci);
3696       break;
3697     case ARM::t2LDRHi12:
3698       Inst.setOpcode(ARM::t2LDRHpci);
3699       break;
3700     case ARM::t2LDRSHi12:
3701       Inst.setOpcode(ARM::t2LDRSHpci);
3702       break;
3703     case ARM::t2LDRBi12:
3704       Inst.setOpcode(ARM::t2LDRBpci);
3705       break;
3706     case ARM::t2LDRSBi12:
3707       Inst.setOpcode(ARM::t2LDRSBpci);
3708       break;
3709     case ARM::t2PLDi12:
3710       Inst.setOpcode(ARM::t2PLDpci);
3711       break;
3712     case ARM::t2PLIi12:
3713       Inst.setOpcode(ARM::t2PLIpci);
3714       break;
3715     default:
3716       return MCDisassembler::Fail;
3717     }
3718     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3719   }
3720 
3721   if (Rt == 15) {
3722     switch (Inst.getOpcode()) {
3723     case ARM::t2LDRSHi12:
3724       return MCDisassembler::Fail;
3725     case ARM::t2LDRHi12:
3726       Inst.setOpcode(ARM::t2PLDWi12);
3727       break;
3728     case ARM::t2LDRSBi12:
3729       Inst.setOpcode(ARM::t2PLIi12);
3730       break;
3731     default:
3732       break;
3733     }
3734   }
3735 
3736   switch (Inst.getOpcode()) {
3737   case ARM::t2PLDi12:
3738     break;
3739   case ARM::t2PLIi12:
3740     if (!hasV7Ops)
3741       return MCDisassembler::Fail;
3742     break;
3743   case ARM::t2PLDWi12:
3744       if (!hasV7Ops || !hasMP)
3745         return MCDisassembler::Fail;
3746       break;
3747   default:
3748     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3749       return MCDisassembler::Fail;
3750   }
3751 
3752   if (!Check(S, DecodeT2AddrModeImm12(Inst, imm, Address, Decoder)))
3753     return MCDisassembler::Fail;
3754   return S;
3755 }
3756 
3757 static DecodeStatus DecodeT2LoadT(MCInst &Inst, unsigned Insn,
3758                                 uint64_t Address, const void* Decoder) {
3759   DecodeStatus S = MCDisassembler::Success;
3760 
3761   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3762   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3763   unsigned imm = fieldFromInstruction(Insn, 0, 8);
3764   imm |= (Rn << 9);
3765 
3766   if (Rn == 15) {
3767     switch (Inst.getOpcode()) {
3768     case ARM::t2LDRT:
3769       Inst.setOpcode(ARM::t2LDRpci);
3770       break;
3771     case ARM::t2LDRBT:
3772       Inst.setOpcode(ARM::t2LDRBpci);
3773       break;
3774     case ARM::t2LDRHT:
3775       Inst.setOpcode(ARM::t2LDRHpci);
3776       break;
3777     case ARM::t2LDRSBT:
3778       Inst.setOpcode(ARM::t2LDRSBpci);
3779       break;
3780     case ARM::t2LDRSHT:
3781       Inst.setOpcode(ARM::t2LDRSHpci);
3782       break;
3783     default:
3784       return MCDisassembler::Fail;
3785     }
3786     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
3787   }
3788 
3789   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
3790     return MCDisassembler::Fail;
3791   if (!Check(S, DecodeT2AddrModeImm8(Inst, imm, Address, Decoder)))
3792     return MCDisassembler::Fail;
3793   return S;
3794 }
3795 
3796 static DecodeStatus DecodeT2LoadLabel(MCInst &Inst, unsigned Insn,
3797                                 uint64_t Address, const void* Decoder) {
3798   DecodeStatus S = MCDisassembler::Success;
3799 
3800   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3801   unsigned U = fieldFromInstruction(Insn, 23, 1);
3802   int imm = fieldFromInstruction(Insn, 0, 12);
3803 
3804   const FeatureBitset &featureBits =
3805     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
3806 
3807   bool hasV7Ops = featureBits[ARM::HasV7Ops];
3808 
3809   if (Rt == 15) {
3810     switch (Inst.getOpcode()) {
3811       case ARM::t2LDRBpci:
3812       case ARM::t2LDRHpci:
3813         Inst.setOpcode(ARM::t2PLDpci);
3814         break;
3815       case ARM::t2LDRSBpci:
3816         Inst.setOpcode(ARM::t2PLIpci);
3817         break;
3818       case ARM::t2LDRSHpci:
3819         return MCDisassembler::Fail;
3820       default:
3821         break;
3822     }
3823   }
3824 
3825   switch(Inst.getOpcode()) {
3826   case ARM::t2PLDpci:
3827     break;
3828   case ARM::t2PLIpci:
3829     if (!hasV7Ops)
3830       return MCDisassembler::Fail;
3831     break;
3832   default:
3833     if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3834       return MCDisassembler::Fail;
3835   }
3836 
3837   if (!U) {
3838     // Special case for #-0.
3839     if (imm == 0)
3840       imm = INT32_MIN;
3841     else
3842       imm = -imm;
3843   }
3844   Inst.addOperand(MCOperand::createImm(imm));
3845 
3846   return S;
3847 }
3848 
3849 static DecodeStatus DecodeT2Imm8S4(MCInst &Inst, unsigned Val,
3850                            uint64_t Address, const void *Decoder) {
3851   if (Val == 0)
3852     Inst.addOperand(MCOperand::createImm(INT32_MIN));
3853   else {
3854     int imm = Val & 0xFF;
3855 
3856     if (!(Val & 0x100)) imm *= -1;
3857     Inst.addOperand(MCOperand::createImm(imm * 4));
3858   }
3859 
3860   return MCDisassembler::Success;
3861 }
3862 
3863 static DecodeStatus DecodeT2Imm7S4(MCInst &Inst, unsigned Val, uint64_t Address,
3864                                    const void *Decoder) {
3865   if (Val == 0)
3866     Inst.addOperand(MCOperand::createImm(INT32_MIN));
3867   else {
3868     int imm = Val & 0x7F;
3869 
3870     if (!(Val & 0x80))
3871       imm *= -1;
3872     Inst.addOperand(MCOperand::createImm(imm * 4));
3873   }
3874 
3875   return MCDisassembler::Success;
3876 }
3877 
3878 static DecodeStatus DecodeT2AddrModeImm8s4(MCInst &Inst, unsigned Val,
3879                                    uint64_t Address, const void *Decoder) {
3880   DecodeStatus S = MCDisassembler::Success;
3881 
3882   unsigned Rn = fieldFromInstruction(Val, 9, 4);
3883   unsigned imm = fieldFromInstruction(Val, 0, 9);
3884 
3885   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3886     return MCDisassembler::Fail;
3887   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
3888     return MCDisassembler::Fail;
3889 
3890   return S;
3891 }
3892 
3893 static DecodeStatus DecodeT2AddrModeImm7s4(MCInst &Inst, unsigned Val,
3894                                            uint64_t Address,
3895                                            const void *Decoder) {
3896   DecodeStatus S = MCDisassembler::Success;
3897 
3898   unsigned Rn = fieldFromInstruction(Val, 8, 4);
3899   unsigned imm = fieldFromInstruction(Val, 0, 8);
3900 
3901   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
3902     return MCDisassembler::Fail;
3903   if (!Check(S, DecodeT2Imm7S4(Inst, imm, Address, Decoder)))
3904     return MCDisassembler::Fail;
3905 
3906   return S;
3907 }
3908 
3909 static DecodeStatus DecodeT2AddrModeImm0_1020s4(MCInst &Inst,unsigned Val,
3910                                    uint64_t Address, const void *Decoder) {
3911   DecodeStatus S = MCDisassembler::Success;
3912 
3913   unsigned Rn = fieldFromInstruction(Val, 8, 4);
3914   unsigned imm = fieldFromInstruction(Val, 0, 8);
3915 
3916   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
3917     return MCDisassembler::Fail;
3918 
3919   Inst.addOperand(MCOperand::createImm(imm));
3920 
3921   return S;
3922 }
3923 
3924 static DecodeStatus DecodeT2Imm8(MCInst &Inst, unsigned Val,
3925                          uint64_t Address, const void *Decoder) {
3926   int imm = Val & 0xFF;
3927   if (Val == 0)
3928     imm = INT32_MIN;
3929   else if (!(Val & 0x100))
3930     imm *= -1;
3931   Inst.addOperand(MCOperand::createImm(imm));
3932 
3933   return MCDisassembler::Success;
3934 }
3935 
3936 static DecodeStatus DecodeT2AddrModeImm8(MCInst &Inst, unsigned Val,
3937                                  uint64_t Address, const void *Decoder) {
3938   DecodeStatus S = MCDisassembler::Success;
3939 
3940   unsigned Rn = fieldFromInstruction(Val, 9, 4);
3941   unsigned imm = fieldFromInstruction(Val, 0, 9);
3942 
3943   // Thumb stores cannot use PC as dest register.
3944   switch (Inst.getOpcode()) {
3945   case ARM::t2STRT:
3946   case ARM::t2STRBT:
3947   case ARM::t2STRHT:
3948   case ARM::t2STRi8:
3949   case ARM::t2STRHi8:
3950   case ARM::t2STRBi8:
3951     if (Rn == 15)
3952       return MCDisassembler::Fail;
3953     break;
3954   default:
3955     break;
3956   }
3957 
3958   // Some instructions always use an additive offset.
3959   switch (Inst.getOpcode()) {
3960     case ARM::t2LDRT:
3961     case ARM::t2LDRBT:
3962     case ARM::t2LDRHT:
3963     case ARM::t2LDRSBT:
3964     case ARM::t2LDRSHT:
3965     case ARM::t2STRT:
3966     case ARM::t2STRBT:
3967     case ARM::t2STRHT:
3968       imm |= 0x100;
3969       break;
3970     default:
3971       break;
3972   }
3973 
3974   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3975     return MCDisassembler::Fail;
3976   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
3977     return MCDisassembler::Fail;
3978 
3979   return S;
3980 }
3981 
3982 static DecodeStatus DecodeT2LdStPre(MCInst &Inst, unsigned Insn,
3983                                     uint64_t Address, const void *Decoder) {
3984   DecodeStatus S = MCDisassembler::Success;
3985 
3986   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
3987   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
3988   unsigned addr = fieldFromInstruction(Insn, 0, 8);
3989   addr |= fieldFromInstruction(Insn, 9, 1) << 8;
3990   addr |= Rn << 9;
3991   unsigned load = fieldFromInstruction(Insn, 20, 1);
3992 
3993   if (Rn == 15) {
3994     switch (Inst.getOpcode()) {
3995     case ARM::t2LDR_PRE:
3996     case ARM::t2LDR_POST:
3997       Inst.setOpcode(ARM::t2LDRpci);
3998       break;
3999     case ARM::t2LDRB_PRE:
4000     case ARM::t2LDRB_POST:
4001       Inst.setOpcode(ARM::t2LDRBpci);
4002       break;
4003     case ARM::t2LDRH_PRE:
4004     case ARM::t2LDRH_POST:
4005       Inst.setOpcode(ARM::t2LDRHpci);
4006       break;
4007     case ARM::t2LDRSB_PRE:
4008     case ARM::t2LDRSB_POST:
4009       if (Rt == 15)
4010         Inst.setOpcode(ARM::t2PLIpci);
4011       else
4012         Inst.setOpcode(ARM::t2LDRSBpci);
4013       break;
4014     case ARM::t2LDRSH_PRE:
4015     case ARM::t2LDRSH_POST:
4016       Inst.setOpcode(ARM::t2LDRSHpci);
4017       break;
4018     default:
4019       return MCDisassembler::Fail;
4020     }
4021     return DecodeT2LoadLabel(Inst, Insn, Address, Decoder);
4022   }
4023 
4024   if (!load) {
4025     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4026       return MCDisassembler::Fail;
4027   }
4028 
4029   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4030     return MCDisassembler::Fail;
4031 
4032   if (load) {
4033     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4034       return MCDisassembler::Fail;
4035   }
4036 
4037   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
4038     return MCDisassembler::Fail;
4039 
4040   return S;
4041 }
4042 
4043 static DecodeStatus DecodeT2AddrModeImm12(MCInst &Inst, unsigned Val,
4044                                   uint64_t Address, const void *Decoder) {
4045   DecodeStatus S = MCDisassembler::Success;
4046 
4047   unsigned Rn = fieldFromInstruction(Val, 13, 4);
4048   unsigned imm = fieldFromInstruction(Val, 0, 12);
4049 
4050   // Thumb stores cannot use PC as dest register.
4051   switch (Inst.getOpcode()) {
4052   case ARM::t2STRi12:
4053   case ARM::t2STRBi12:
4054   case ARM::t2STRHi12:
4055     if (Rn == 15)
4056       return MCDisassembler::Fail;
4057     break;
4058   default:
4059     break;
4060   }
4061 
4062   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4063     return MCDisassembler::Fail;
4064   Inst.addOperand(MCOperand::createImm(imm));
4065 
4066   return S;
4067 }
4068 
4069 static DecodeStatus DecodeThumbAddSPImm(MCInst &Inst, uint16_t Insn,
4070                                 uint64_t Address, const void *Decoder) {
4071   unsigned imm = fieldFromInstruction(Insn, 0, 7);
4072 
4073   Inst.addOperand(MCOperand::createReg(ARM::SP));
4074   Inst.addOperand(MCOperand::createReg(ARM::SP));
4075   Inst.addOperand(MCOperand::createImm(imm));
4076 
4077   return MCDisassembler::Success;
4078 }
4079 
4080 static DecodeStatus DecodeThumbAddSPReg(MCInst &Inst, uint16_t Insn,
4081                                 uint64_t Address, const void *Decoder) {
4082   DecodeStatus S = MCDisassembler::Success;
4083 
4084   if (Inst.getOpcode() == ARM::tADDrSP) {
4085     unsigned Rdm = fieldFromInstruction(Insn, 0, 3);
4086     Rdm |= fieldFromInstruction(Insn, 7, 1) << 3;
4087 
4088     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4089     return MCDisassembler::Fail;
4090     Inst.addOperand(MCOperand::createReg(ARM::SP));
4091     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
4092     return MCDisassembler::Fail;
4093   } else if (Inst.getOpcode() == ARM::tADDspr) {
4094     unsigned Rm = fieldFromInstruction(Insn, 3, 4);
4095 
4096     Inst.addOperand(MCOperand::createReg(ARM::SP));
4097     Inst.addOperand(MCOperand::createReg(ARM::SP));
4098     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4099     return MCDisassembler::Fail;
4100   }
4101 
4102   return S;
4103 }
4104 
4105 static DecodeStatus DecodeThumbCPS(MCInst &Inst, uint16_t Insn,
4106                            uint64_t Address, const void *Decoder) {
4107   unsigned imod = fieldFromInstruction(Insn, 4, 1) | 0x2;
4108   unsigned flags = fieldFromInstruction(Insn, 0, 3);
4109 
4110   Inst.addOperand(MCOperand::createImm(imod));
4111   Inst.addOperand(MCOperand::createImm(flags));
4112 
4113   return MCDisassembler::Success;
4114 }
4115 
4116 static DecodeStatus DecodePostIdxReg(MCInst &Inst, unsigned Insn,
4117                              uint64_t Address, const void *Decoder) {
4118   DecodeStatus S = MCDisassembler::Success;
4119   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4120   unsigned add = fieldFromInstruction(Insn, 4, 1);
4121 
4122   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
4123     return MCDisassembler::Fail;
4124   Inst.addOperand(MCOperand::createImm(add));
4125 
4126   return S;
4127 }
4128 
4129 static DecodeStatus DecodeThumbBLXOffset(MCInst &Inst, unsigned Val,
4130                                  uint64_t Address, const void *Decoder) {
4131   // Val is passed in as S:J1:J2:imm10H:imm10L:'0'
4132   // Note only one trailing zero not two.  Also the J1 and J2 values are from
4133   // the encoded instruction.  So here change to I1 and I2 values via:
4134   // I1 = NOT(J1 EOR S);
4135   // I2 = NOT(J2 EOR S);
4136   // and build the imm32 with two trailing zeros as documented:
4137   // imm32 = SignExtend(S:I1:I2:imm10H:imm10L:'00', 32);
4138   unsigned S = (Val >> 23) & 1;
4139   unsigned J1 = (Val >> 22) & 1;
4140   unsigned J2 = (Val >> 21) & 1;
4141   unsigned I1 = !(J1 ^ S);
4142   unsigned I2 = !(J2 ^ S);
4143   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4144   int imm32 = SignExtend32<25>(tmp << 1);
4145 
4146   if (!tryAddingSymbolicOperand(Address,
4147                                 (Address & ~2u) + imm32 + 4,
4148                                 true, 4, Inst, Decoder))
4149     Inst.addOperand(MCOperand::createImm(imm32));
4150   return MCDisassembler::Success;
4151 }
4152 
4153 static DecodeStatus DecodeCoprocessor(MCInst &Inst, unsigned Val,
4154                               uint64_t Address, const void *Decoder) {
4155   if (Val == 0xA || Val == 0xB)
4156     return MCDisassembler::Fail;
4157 
4158   const FeatureBitset &featureBits =
4159     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4160 
4161   if (featureBits[ARM::HasV8Ops] && !(Val == 14 || Val == 15))
4162     return MCDisassembler::Fail;
4163 
4164   // For Armv8.1-M Mainline coprocessors matching 100x,101x or 111x should
4165   // decode as VFP/MVE instructions.
4166   if (featureBits[ARM::HasV8_1MMainlineOps] &&
4167       ((Val & 0xE) == 0x8 || (Val & 0xE) == 0xA ||
4168        (Val & 0xE) == 0xE))
4169     return MCDisassembler::Fail;
4170 
4171   Inst.addOperand(MCOperand::createImm(Val));
4172   return MCDisassembler::Success;
4173 }
4174 
4175 static DecodeStatus
4176 DecodeThumbTableBranch(MCInst &Inst, unsigned Insn,
4177                        uint64_t Address, const void *Decoder) {
4178   DecodeStatus S = MCDisassembler::Success;
4179 
4180   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4181   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4182 
4183   if (Rn == ARM::SP) S = MCDisassembler::SoftFail;
4184   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4185     return MCDisassembler::Fail;
4186   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
4187     return MCDisassembler::Fail;
4188   return S;
4189 }
4190 
4191 static DecodeStatus
4192 DecodeThumb2BCCInstruction(MCInst &Inst, unsigned Insn,
4193                            uint64_t Address, const void *Decoder) {
4194   DecodeStatus S = MCDisassembler::Success;
4195 
4196   unsigned pred = fieldFromInstruction(Insn, 22, 4);
4197   if (pred == 0xE || pred == 0xF) {
4198     unsigned opc = fieldFromInstruction(Insn, 4, 28);
4199     switch (opc) {
4200       default:
4201         return MCDisassembler::Fail;
4202       case 0xf3bf8f4:
4203         Inst.setOpcode(ARM::t2DSB);
4204         break;
4205       case 0xf3bf8f5:
4206         Inst.setOpcode(ARM::t2DMB);
4207         break;
4208       case 0xf3bf8f6:
4209         Inst.setOpcode(ARM::t2ISB);
4210         break;
4211     }
4212 
4213     unsigned imm = fieldFromInstruction(Insn, 0, 4);
4214     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
4215   }
4216 
4217   unsigned brtarget = fieldFromInstruction(Insn, 0, 11) << 1;
4218   brtarget |= fieldFromInstruction(Insn, 11, 1) << 19;
4219   brtarget |= fieldFromInstruction(Insn, 13, 1) << 18;
4220   brtarget |= fieldFromInstruction(Insn, 16, 6) << 12;
4221   brtarget |= fieldFromInstruction(Insn, 26, 1) << 20;
4222 
4223   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
4224     return MCDisassembler::Fail;
4225   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4226     return MCDisassembler::Fail;
4227 
4228   return S;
4229 }
4230 
4231 // Decode a shifted immediate operand.  These basically consist
4232 // of an 8-bit value, and a 4-bit directive that specifies either
4233 // a splat operation or a rotation.
4234 static DecodeStatus DecodeT2SOImm(MCInst &Inst, unsigned Val,
4235                           uint64_t Address, const void *Decoder) {
4236   unsigned ctrl = fieldFromInstruction(Val, 10, 2);
4237   if (ctrl == 0) {
4238     unsigned byte = fieldFromInstruction(Val, 8, 2);
4239     unsigned imm = fieldFromInstruction(Val, 0, 8);
4240     switch (byte) {
4241       case 0:
4242         Inst.addOperand(MCOperand::createImm(imm));
4243         break;
4244       case 1:
4245         Inst.addOperand(MCOperand::createImm((imm << 16) | imm));
4246         break;
4247       case 2:
4248         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 8)));
4249         break;
4250       case 3:
4251         Inst.addOperand(MCOperand::createImm((imm << 24) | (imm << 16) |
4252                                              (imm << 8)  |  imm));
4253         break;
4254     }
4255   } else {
4256     unsigned unrot = fieldFromInstruction(Val, 0, 7) | 0x80;
4257     unsigned rot = fieldFromInstruction(Val, 7, 5);
4258     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
4259     Inst.addOperand(MCOperand::createImm(imm));
4260   }
4261 
4262   return MCDisassembler::Success;
4263 }
4264 
4265 static DecodeStatus
4266 DecodeThumbBCCTargetOperand(MCInst &Inst, unsigned Val,
4267                             uint64_t Address, const void *Decoder) {
4268   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<9>(Val<<1) + 4,
4269                                 true, 2, Inst, Decoder))
4270     Inst.addOperand(MCOperand::createImm(SignExtend32<9>(Val << 1)));
4271   return MCDisassembler::Success;
4272 }
4273 
4274 static DecodeStatus DecodeThumbBLTargetOperand(MCInst &Inst, unsigned Val,
4275                                                uint64_t Address,
4276                                                const void *Decoder) {
4277   // Val is passed in as S:J1:J2:imm10:imm11
4278   // Note no trailing zero after imm11.  Also the J1 and J2 values are from
4279   // the encoded instruction.  So here change to I1 and I2 values via:
4280   // I1 = NOT(J1 EOR S);
4281   // I2 = NOT(J2 EOR S);
4282   // and build the imm32 with one trailing zero as documented:
4283   // imm32 = SignExtend(S:I1:I2:imm10:imm11:'0', 32);
4284   unsigned S = (Val >> 23) & 1;
4285   unsigned J1 = (Val >> 22) & 1;
4286   unsigned J2 = (Val >> 21) & 1;
4287   unsigned I1 = !(J1 ^ S);
4288   unsigned I2 = !(J2 ^ S);
4289   unsigned tmp = (Val & ~0x600000) | (I1 << 22) | (I2 << 21);
4290   int imm32 = SignExtend32<25>(tmp << 1);
4291 
4292   if (!tryAddingSymbolicOperand(Address, Address + imm32 + 4,
4293                                 true, 4, Inst, Decoder))
4294     Inst.addOperand(MCOperand::createImm(imm32));
4295   return MCDisassembler::Success;
4296 }
4297 
4298 static DecodeStatus DecodeMemBarrierOption(MCInst &Inst, unsigned Val,
4299                                    uint64_t Address, const void *Decoder) {
4300   if (Val & ~0xf)
4301     return MCDisassembler::Fail;
4302 
4303   Inst.addOperand(MCOperand::createImm(Val));
4304   return MCDisassembler::Success;
4305 }
4306 
4307 static DecodeStatus DecodeInstSyncBarrierOption(MCInst &Inst, unsigned Val,
4308                                         uint64_t Address, const void *Decoder) {
4309   if (Val & ~0xf)
4310     return MCDisassembler::Fail;
4311 
4312   Inst.addOperand(MCOperand::createImm(Val));
4313   return MCDisassembler::Success;
4314 }
4315 
4316 static DecodeStatus DecodeMSRMask(MCInst &Inst, unsigned Val,
4317                           uint64_t Address, const void *Decoder) {
4318   DecodeStatus S = MCDisassembler::Success;
4319   const FeatureBitset &FeatureBits =
4320     ((const MCDisassembler*)Decoder)->getSubtargetInfo().getFeatureBits();
4321 
4322   if (FeatureBits[ARM::FeatureMClass]) {
4323     unsigned ValLow = Val & 0xff;
4324 
4325     // Validate the SYSm value first.
4326     switch (ValLow) {
4327     case  0: // apsr
4328     case  1: // iapsr
4329     case  2: // eapsr
4330     case  3: // xpsr
4331     case  5: // ipsr
4332     case  6: // epsr
4333     case  7: // iepsr
4334     case  8: // msp
4335     case  9: // psp
4336     case 16: // primask
4337     case 20: // control
4338       break;
4339     case 17: // basepri
4340     case 18: // basepri_max
4341     case 19: // faultmask
4342       if (!(FeatureBits[ARM::HasV7Ops]))
4343         // Values basepri, basepri_max and faultmask are only valid for v7m.
4344         return MCDisassembler::Fail;
4345       break;
4346     case 0x8a: // msplim_ns
4347     case 0x8b: // psplim_ns
4348     case 0x91: // basepri_ns
4349     case 0x93: // faultmask_ns
4350       if (!(FeatureBits[ARM::HasV8MMainlineOps]))
4351         return MCDisassembler::Fail;
4352       LLVM_FALLTHROUGH;
4353     case 10:   // msplim
4354     case 11:   // psplim
4355     case 0x88: // msp_ns
4356     case 0x89: // psp_ns
4357     case 0x90: // primask_ns
4358     case 0x94: // control_ns
4359     case 0x98: // sp_ns
4360       if (!(FeatureBits[ARM::Feature8MSecExt]))
4361         return MCDisassembler::Fail;
4362       break;
4363     default:
4364       // Architecturally defined as unpredictable
4365       S = MCDisassembler::SoftFail;
4366       break;
4367     }
4368 
4369     if (Inst.getOpcode() == ARM::t2MSR_M) {
4370       unsigned Mask = fieldFromInstruction(Val, 10, 2);
4371       if (!(FeatureBits[ARM::HasV7Ops])) {
4372         // The ARMv6-M MSR bits {11-10} can be only 0b10, other values are
4373         // unpredictable.
4374         if (Mask != 2)
4375           S = MCDisassembler::SoftFail;
4376       }
4377       else {
4378         // The ARMv7-M architecture stores an additional 2-bit mask value in
4379         // MSR bits {11-10}. The mask is used only with apsr, iapsr, eapsr and
4380         // xpsr, it has to be 0b10 in other cases. Bit mask{1} indicates if
4381         // the NZCVQ bits should be moved by the instruction. Bit mask{0}
4382         // indicates the move for the GE{3:0} bits, the mask{0} bit can be set
4383         // only if the processor includes the DSP extension.
4384         if (Mask == 0 || (Mask != 2 && ValLow > 3) ||
4385             (!(FeatureBits[ARM::FeatureDSP]) && (Mask & 1)))
4386           S = MCDisassembler::SoftFail;
4387       }
4388     }
4389   } else {
4390     // A/R class
4391     if (Val == 0)
4392       return MCDisassembler::Fail;
4393   }
4394   Inst.addOperand(MCOperand::createImm(Val));
4395   return S;
4396 }
4397 
4398 static DecodeStatus DecodeBankedReg(MCInst &Inst, unsigned Val,
4399                                     uint64_t Address, const void *Decoder) {
4400   unsigned R = fieldFromInstruction(Val, 5, 1);
4401   unsigned SysM = fieldFromInstruction(Val, 0, 5);
4402 
4403   // The table of encodings for these banked registers comes from B9.2.3 of the
4404   // ARM ARM. There are patterns, but nothing regular enough to make this logic
4405   // neater. So by fiat, these values are UNPREDICTABLE:
4406   if (!ARMBankedReg::lookupBankedRegByEncoding((R << 5) | SysM))
4407     return MCDisassembler::Fail;
4408 
4409   Inst.addOperand(MCOperand::createImm(Val));
4410   return MCDisassembler::Success;
4411 }
4412 
4413 static DecodeStatus DecodeDoubleRegLoad(MCInst &Inst, unsigned Insn,
4414                                         uint64_t Address, const void *Decoder) {
4415   DecodeStatus S = MCDisassembler::Success;
4416 
4417   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4418   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4419   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4420 
4421   if (Rn == 0xF)
4422     S = MCDisassembler::SoftFail;
4423 
4424   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4425     return MCDisassembler::Fail;
4426   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4427     return MCDisassembler::Fail;
4428   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4429     return MCDisassembler::Fail;
4430 
4431   return S;
4432 }
4433 
4434 static DecodeStatus DecodeDoubleRegStore(MCInst &Inst, unsigned Insn,
4435                                          uint64_t Address,
4436                                          const void *Decoder) {
4437   DecodeStatus S = MCDisassembler::Success;
4438 
4439   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4440   unsigned Rt = fieldFromInstruction(Insn, 0, 4);
4441   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4442   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4443 
4444   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
4445     return MCDisassembler::Fail;
4446 
4447   if (Rn == 0xF || Rd == Rn || Rd == Rt || Rd == Rt+1)
4448     S = MCDisassembler::SoftFail;
4449 
4450   if (!Check(S, DecodeGPRPairRegisterClass(Inst, Rt, Address, Decoder)))
4451     return MCDisassembler::Fail;
4452   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4453     return MCDisassembler::Fail;
4454   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4455     return MCDisassembler::Fail;
4456 
4457   return S;
4458 }
4459 
4460 static DecodeStatus DecodeLDRPreImm(MCInst &Inst, unsigned Insn,
4461                             uint64_t Address, const void *Decoder) {
4462   DecodeStatus S = MCDisassembler::Success;
4463 
4464   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4465   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4466   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4467   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4468   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4469   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4470 
4471   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4472 
4473   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4474     return MCDisassembler::Fail;
4475   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4476     return MCDisassembler::Fail;
4477   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4478     return MCDisassembler::Fail;
4479   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4480     return MCDisassembler::Fail;
4481 
4482   return S;
4483 }
4484 
4485 static DecodeStatus DecodeLDRPreReg(MCInst &Inst, unsigned Insn,
4486                             uint64_t Address, const void *Decoder) {
4487   DecodeStatus S = MCDisassembler::Success;
4488 
4489   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4490   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4491   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4492   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4493   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4494   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4495   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4496 
4497   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4498   if (Rm == 0xF) S = MCDisassembler::SoftFail;
4499 
4500   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4501     return MCDisassembler::Fail;
4502   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4503     return MCDisassembler::Fail;
4504   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4505     return MCDisassembler::Fail;
4506   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4507     return MCDisassembler::Fail;
4508 
4509   return S;
4510 }
4511 
4512 static DecodeStatus DecodeSTRPreImm(MCInst &Inst, unsigned Insn,
4513                             uint64_t Address, const void *Decoder) {
4514   DecodeStatus S = MCDisassembler::Success;
4515 
4516   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4517   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4518   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4519   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4520   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4521   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4522 
4523   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4524 
4525   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4526     return MCDisassembler::Fail;
4527   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4528     return MCDisassembler::Fail;
4529   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
4530     return MCDisassembler::Fail;
4531   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4532     return MCDisassembler::Fail;
4533 
4534   return S;
4535 }
4536 
4537 static DecodeStatus DecodeSTRPreReg(MCInst &Inst, unsigned Insn,
4538                             uint64_t Address, const void *Decoder) {
4539   DecodeStatus S = MCDisassembler::Success;
4540 
4541   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4542   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
4543   unsigned imm = fieldFromInstruction(Insn, 0, 12);
4544   imm |= fieldFromInstruction(Insn, 16, 4) << 13;
4545   imm |= fieldFromInstruction(Insn, 23, 1) << 12;
4546   unsigned pred = fieldFromInstruction(Insn, 28, 4);
4547 
4548   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
4549 
4550   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4551     return MCDisassembler::Fail;
4552   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
4553     return MCDisassembler::Fail;
4554   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
4555     return MCDisassembler::Fail;
4556   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
4557     return MCDisassembler::Fail;
4558 
4559   return S;
4560 }
4561 
4562 static DecodeStatus DecodeVLD1LN(MCInst &Inst, unsigned Insn,
4563                          uint64_t Address, const void *Decoder) {
4564   DecodeStatus S = MCDisassembler::Success;
4565 
4566   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4567   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4568   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4569   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4570   unsigned size = fieldFromInstruction(Insn, 10, 2);
4571 
4572   unsigned align = 0;
4573   unsigned index = 0;
4574   switch (size) {
4575     default:
4576       return MCDisassembler::Fail;
4577     case 0:
4578       if (fieldFromInstruction(Insn, 4, 1))
4579         return MCDisassembler::Fail; // UNDEFINED
4580       index = fieldFromInstruction(Insn, 5, 3);
4581       break;
4582     case 1:
4583       if (fieldFromInstruction(Insn, 5, 1))
4584         return MCDisassembler::Fail; // UNDEFINED
4585       index = fieldFromInstruction(Insn, 6, 2);
4586       if (fieldFromInstruction(Insn, 4, 1))
4587         align = 2;
4588       break;
4589     case 2:
4590       if (fieldFromInstruction(Insn, 6, 1))
4591         return MCDisassembler::Fail; // UNDEFINED
4592       index = fieldFromInstruction(Insn, 7, 1);
4593 
4594       switch (fieldFromInstruction(Insn, 4, 2)) {
4595         case 0 :
4596           align = 0; break;
4597         case 3:
4598           align = 4; break;
4599         default:
4600           return MCDisassembler::Fail;
4601       }
4602       break;
4603   }
4604 
4605   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4606     return MCDisassembler::Fail;
4607   if (Rm != 0xF) { // Writeback
4608     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4609       return MCDisassembler::Fail;
4610   }
4611   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4612     return MCDisassembler::Fail;
4613   Inst.addOperand(MCOperand::createImm(align));
4614   if (Rm != 0xF) {
4615     if (Rm != 0xD) {
4616       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4617         return MCDisassembler::Fail;
4618     } else
4619       Inst.addOperand(MCOperand::createReg(0));
4620   }
4621 
4622   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4623     return MCDisassembler::Fail;
4624   Inst.addOperand(MCOperand::createImm(index));
4625 
4626   return S;
4627 }
4628 
4629 static DecodeStatus DecodeVST1LN(MCInst &Inst, unsigned Insn,
4630                          uint64_t Address, const void *Decoder) {
4631   DecodeStatus S = MCDisassembler::Success;
4632 
4633   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4634   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4635   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4636   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4637   unsigned size = fieldFromInstruction(Insn, 10, 2);
4638 
4639   unsigned align = 0;
4640   unsigned index = 0;
4641   switch (size) {
4642     default:
4643       return MCDisassembler::Fail;
4644     case 0:
4645       if (fieldFromInstruction(Insn, 4, 1))
4646         return MCDisassembler::Fail; // UNDEFINED
4647       index = fieldFromInstruction(Insn, 5, 3);
4648       break;
4649     case 1:
4650       if (fieldFromInstruction(Insn, 5, 1))
4651         return MCDisassembler::Fail; // UNDEFINED
4652       index = fieldFromInstruction(Insn, 6, 2);
4653       if (fieldFromInstruction(Insn, 4, 1))
4654         align = 2;
4655       break;
4656     case 2:
4657       if (fieldFromInstruction(Insn, 6, 1))
4658         return MCDisassembler::Fail; // UNDEFINED
4659       index = fieldFromInstruction(Insn, 7, 1);
4660 
4661       switch (fieldFromInstruction(Insn, 4, 2)) {
4662         case 0:
4663           align = 0; break;
4664         case 3:
4665           align = 4; break;
4666         default:
4667           return MCDisassembler::Fail;
4668       }
4669       break;
4670   }
4671 
4672   if (Rm != 0xF) { // Writeback
4673     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4674     return MCDisassembler::Fail;
4675   }
4676   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4677     return MCDisassembler::Fail;
4678   Inst.addOperand(MCOperand::createImm(align));
4679   if (Rm != 0xF) {
4680     if (Rm != 0xD) {
4681       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4682     return MCDisassembler::Fail;
4683     } else
4684       Inst.addOperand(MCOperand::createReg(0));
4685   }
4686 
4687   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4688     return MCDisassembler::Fail;
4689   Inst.addOperand(MCOperand::createImm(index));
4690 
4691   return S;
4692 }
4693 
4694 static DecodeStatus DecodeVLD2LN(MCInst &Inst, unsigned Insn,
4695                          uint64_t Address, const void *Decoder) {
4696   DecodeStatus S = MCDisassembler::Success;
4697 
4698   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4699   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4700   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4701   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4702   unsigned size = fieldFromInstruction(Insn, 10, 2);
4703 
4704   unsigned align = 0;
4705   unsigned index = 0;
4706   unsigned inc = 1;
4707   switch (size) {
4708     default:
4709       return MCDisassembler::Fail;
4710     case 0:
4711       index = fieldFromInstruction(Insn, 5, 3);
4712       if (fieldFromInstruction(Insn, 4, 1))
4713         align = 2;
4714       break;
4715     case 1:
4716       index = fieldFromInstruction(Insn, 6, 2);
4717       if (fieldFromInstruction(Insn, 4, 1))
4718         align = 4;
4719       if (fieldFromInstruction(Insn, 5, 1))
4720         inc = 2;
4721       break;
4722     case 2:
4723       if (fieldFromInstruction(Insn, 5, 1))
4724         return MCDisassembler::Fail; // UNDEFINED
4725       index = fieldFromInstruction(Insn, 7, 1);
4726       if (fieldFromInstruction(Insn, 4, 1) != 0)
4727         align = 8;
4728       if (fieldFromInstruction(Insn, 6, 1))
4729         inc = 2;
4730       break;
4731   }
4732 
4733   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4734     return MCDisassembler::Fail;
4735   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4736     return MCDisassembler::Fail;
4737   if (Rm != 0xF) { // Writeback
4738     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4739       return MCDisassembler::Fail;
4740   }
4741   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4742     return MCDisassembler::Fail;
4743   Inst.addOperand(MCOperand::createImm(align));
4744   if (Rm != 0xF) {
4745     if (Rm != 0xD) {
4746       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4747         return MCDisassembler::Fail;
4748     } else
4749       Inst.addOperand(MCOperand::createReg(0));
4750   }
4751 
4752   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4753     return MCDisassembler::Fail;
4754   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4755     return MCDisassembler::Fail;
4756   Inst.addOperand(MCOperand::createImm(index));
4757 
4758   return S;
4759 }
4760 
4761 static DecodeStatus DecodeVST2LN(MCInst &Inst, unsigned Insn,
4762                          uint64_t Address, const void *Decoder) {
4763   DecodeStatus S = MCDisassembler::Success;
4764 
4765   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4766   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4767   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4768   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4769   unsigned size = fieldFromInstruction(Insn, 10, 2);
4770 
4771   unsigned align = 0;
4772   unsigned index = 0;
4773   unsigned inc = 1;
4774   switch (size) {
4775     default:
4776       return MCDisassembler::Fail;
4777     case 0:
4778       index = fieldFromInstruction(Insn, 5, 3);
4779       if (fieldFromInstruction(Insn, 4, 1))
4780         align = 2;
4781       break;
4782     case 1:
4783       index = fieldFromInstruction(Insn, 6, 2);
4784       if (fieldFromInstruction(Insn, 4, 1))
4785         align = 4;
4786       if (fieldFromInstruction(Insn, 5, 1))
4787         inc = 2;
4788       break;
4789     case 2:
4790       if (fieldFromInstruction(Insn, 5, 1))
4791         return MCDisassembler::Fail; // UNDEFINED
4792       index = fieldFromInstruction(Insn, 7, 1);
4793       if (fieldFromInstruction(Insn, 4, 1) != 0)
4794         align = 8;
4795       if (fieldFromInstruction(Insn, 6, 1))
4796         inc = 2;
4797       break;
4798   }
4799 
4800   if (Rm != 0xF) { // Writeback
4801     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4802       return MCDisassembler::Fail;
4803   }
4804   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4805     return MCDisassembler::Fail;
4806   Inst.addOperand(MCOperand::createImm(align));
4807   if (Rm != 0xF) {
4808     if (Rm != 0xD) {
4809       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4810         return MCDisassembler::Fail;
4811     } else
4812       Inst.addOperand(MCOperand::createReg(0));
4813   }
4814 
4815   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4816     return MCDisassembler::Fail;
4817   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4818     return MCDisassembler::Fail;
4819   Inst.addOperand(MCOperand::createImm(index));
4820 
4821   return S;
4822 }
4823 
4824 static DecodeStatus DecodeVLD3LN(MCInst &Inst, unsigned Insn,
4825                          uint64_t Address, const void *Decoder) {
4826   DecodeStatus S = MCDisassembler::Success;
4827 
4828   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4829   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4830   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4831   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4832   unsigned size = fieldFromInstruction(Insn, 10, 2);
4833 
4834   unsigned align = 0;
4835   unsigned index = 0;
4836   unsigned inc = 1;
4837   switch (size) {
4838     default:
4839       return MCDisassembler::Fail;
4840     case 0:
4841       if (fieldFromInstruction(Insn, 4, 1))
4842         return MCDisassembler::Fail; // UNDEFINED
4843       index = fieldFromInstruction(Insn, 5, 3);
4844       break;
4845     case 1:
4846       if (fieldFromInstruction(Insn, 4, 1))
4847         return MCDisassembler::Fail; // UNDEFINED
4848       index = fieldFromInstruction(Insn, 6, 2);
4849       if (fieldFromInstruction(Insn, 5, 1))
4850         inc = 2;
4851       break;
4852     case 2:
4853       if (fieldFromInstruction(Insn, 4, 2))
4854         return MCDisassembler::Fail; // UNDEFINED
4855       index = fieldFromInstruction(Insn, 7, 1);
4856       if (fieldFromInstruction(Insn, 6, 1))
4857         inc = 2;
4858       break;
4859   }
4860 
4861   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4862     return MCDisassembler::Fail;
4863   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4864     return MCDisassembler::Fail;
4865   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4866     return MCDisassembler::Fail;
4867 
4868   if (Rm != 0xF) { // Writeback
4869     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4870     return MCDisassembler::Fail;
4871   }
4872   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4873     return MCDisassembler::Fail;
4874   Inst.addOperand(MCOperand::createImm(align));
4875   if (Rm != 0xF) {
4876     if (Rm != 0xD) {
4877       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4878     return MCDisassembler::Fail;
4879     } else
4880       Inst.addOperand(MCOperand::createReg(0));
4881   }
4882 
4883   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4884     return MCDisassembler::Fail;
4885   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4886     return MCDisassembler::Fail;
4887   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4888     return MCDisassembler::Fail;
4889   Inst.addOperand(MCOperand::createImm(index));
4890 
4891   return S;
4892 }
4893 
4894 static DecodeStatus DecodeVST3LN(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 Rm = fieldFromInstruction(Insn, 0, 4);
4900   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4901   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4902   unsigned size = fieldFromInstruction(Insn, 10, 2);
4903 
4904   unsigned align = 0;
4905   unsigned index = 0;
4906   unsigned inc = 1;
4907   switch (size) {
4908     default:
4909       return MCDisassembler::Fail;
4910     case 0:
4911       if (fieldFromInstruction(Insn, 4, 1))
4912         return MCDisassembler::Fail; // UNDEFINED
4913       index = fieldFromInstruction(Insn, 5, 3);
4914       break;
4915     case 1:
4916       if (fieldFromInstruction(Insn, 4, 1))
4917         return MCDisassembler::Fail; // UNDEFINED
4918       index = fieldFromInstruction(Insn, 6, 2);
4919       if (fieldFromInstruction(Insn, 5, 1))
4920         inc = 2;
4921       break;
4922     case 2:
4923       if (fieldFromInstruction(Insn, 4, 2))
4924         return MCDisassembler::Fail; // UNDEFINED
4925       index = fieldFromInstruction(Insn, 7, 1);
4926       if (fieldFromInstruction(Insn, 6, 1))
4927         inc = 2;
4928       break;
4929   }
4930 
4931   if (Rm != 0xF) { // Writeback
4932     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4933     return MCDisassembler::Fail;
4934   }
4935   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
4936     return MCDisassembler::Fail;
4937   Inst.addOperand(MCOperand::createImm(align));
4938   if (Rm != 0xF) {
4939     if (Rm != 0xD) {
4940       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
4941     return MCDisassembler::Fail;
4942     } else
4943       Inst.addOperand(MCOperand::createReg(0));
4944   }
4945 
4946   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
4947     return MCDisassembler::Fail;
4948   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
4949     return MCDisassembler::Fail;
4950   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
4951     return MCDisassembler::Fail;
4952   Inst.addOperand(MCOperand::createImm(index));
4953 
4954   return S;
4955 }
4956 
4957 static DecodeStatus DecodeVLD4LN(MCInst &Inst, unsigned Insn,
4958                          uint64_t Address, const void *Decoder) {
4959   DecodeStatus S = MCDisassembler::Success;
4960 
4961   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
4962   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
4963   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
4964   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
4965   unsigned size = fieldFromInstruction(Insn, 10, 2);
4966 
4967   unsigned align = 0;
4968   unsigned index = 0;
4969   unsigned inc = 1;
4970   switch (size) {
4971     default:
4972       return MCDisassembler::Fail;
4973     case 0:
4974       if (fieldFromInstruction(Insn, 4, 1))
4975         align = 4;
4976       index = fieldFromInstruction(Insn, 5, 3);
4977       break;
4978     case 1:
4979       if (fieldFromInstruction(Insn, 4, 1))
4980         align = 8;
4981       index = fieldFromInstruction(Insn, 6, 2);
4982       if (fieldFromInstruction(Insn, 5, 1))
4983         inc = 2;
4984       break;
4985     case 2:
4986       switch (fieldFromInstruction(Insn, 4, 2)) {
4987         case 0:
4988           align = 0; break;
4989         case 3:
4990           return MCDisassembler::Fail;
4991         default:
4992           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
4993       }
4994 
4995       index = fieldFromInstruction(Insn, 7, 1);
4996       if (fieldFromInstruction(Insn, 6, 1))
4997         inc = 2;
4998       break;
4999   }
5000 
5001   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5002     return MCDisassembler::Fail;
5003   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5004     return MCDisassembler::Fail;
5005   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5006     return MCDisassembler::Fail;
5007   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5008     return MCDisassembler::Fail;
5009 
5010   if (Rm != 0xF) { // Writeback
5011     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5012       return MCDisassembler::Fail;
5013   }
5014   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5015     return MCDisassembler::Fail;
5016   Inst.addOperand(MCOperand::createImm(align));
5017   if (Rm != 0xF) {
5018     if (Rm != 0xD) {
5019       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5020         return MCDisassembler::Fail;
5021     } else
5022       Inst.addOperand(MCOperand::createReg(0));
5023   }
5024 
5025   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5026     return MCDisassembler::Fail;
5027   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5028     return MCDisassembler::Fail;
5029   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5030     return MCDisassembler::Fail;
5031   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5032     return MCDisassembler::Fail;
5033   Inst.addOperand(MCOperand::createImm(index));
5034 
5035   return S;
5036 }
5037 
5038 static DecodeStatus DecodeVST4LN(MCInst &Inst, unsigned Insn,
5039                          uint64_t Address, const void *Decoder) {
5040   DecodeStatus S = MCDisassembler::Success;
5041 
5042   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5043   unsigned Rm = fieldFromInstruction(Insn, 0, 4);
5044   unsigned Rd = fieldFromInstruction(Insn, 12, 4);
5045   Rd |= fieldFromInstruction(Insn, 22, 1) << 4;
5046   unsigned size = fieldFromInstruction(Insn, 10, 2);
5047 
5048   unsigned align = 0;
5049   unsigned index = 0;
5050   unsigned inc = 1;
5051   switch (size) {
5052     default:
5053       return MCDisassembler::Fail;
5054     case 0:
5055       if (fieldFromInstruction(Insn, 4, 1))
5056         align = 4;
5057       index = fieldFromInstruction(Insn, 5, 3);
5058       break;
5059     case 1:
5060       if (fieldFromInstruction(Insn, 4, 1))
5061         align = 8;
5062       index = fieldFromInstruction(Insn, 6, 2);
5063       if (fieldFromInstruction(Insn, 5, 1))
5064         inc = 2;
5065       break;
5066     case 2:
5067       switch (fieldFromInstruction(Insn, 4, 2)) {
5068         case 0:
5069           align = 0; break;
5070         case 3:
5071           return MCDisassembler::Fail;
5072         default:
5073           align = 4 << fieldFromInstruction(Insn, 4, 2); break;
5074       }
5075 
5076       index = fieldFromInstruction(Insn, 7, 1);
5077       if (fieldFromInstruction(Insn, 6, 1))
5078         inc = 2;
5079       break;
5080   }
5081 
5082   if (Rm != 0xF) { // Writeback
5083     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5084     return MCDisassembler::Fail;
5085   }
5086   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
5087     return MCDisassembler::Fail;
5088   Inst.addOperand(MCOperand::createImm(align));
5089   if (Rm != 0xF) {
5090     if (Rm != 0xD) {
5091       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
5092     return MCDisassembler::Fail;
5093     } else
5094       Inst.addOperand(MCOperand::createReg(0));
5095   }
5096 
5097   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
5098     return MCDisassembler::Fail;
5099   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
5100     return MCDisassembler::Fail;
5101   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
5102     return MCDisassembler::Fail;
5103   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
5104     return MCDisassembler::Fail;
5105   Inst.addOperand(MCOperand::createImm(index));
5106 
5107   return S;
5108 }
5109 
5110 static DecodeStatus DecodeVMOVSRR(MCInst &Inst, unsigned Insn,
5111                                   uint64_t Address, const void *Decoder) {
5112   DecodeStatus S = MCDisassembler::Success;
5113   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5114   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5115   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5116   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5117   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5118 
5119   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5120     S = MCDisassembler::SoftFail;
5121 
5122   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5123     return MCDisassembler::Fail;
5124   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5125     return MCDisassembler::Fail;
5126   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5127     return MCDisassembler::Fail;
5128   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5129     return MCDisassembler::Fail;
5130   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5131     return MCDisassembler::Fail;
5132 
5133   return S;
5134 }
5135 
5136 static DecodeStatus DecodeVMOVRRS(MCInst &Inst, unsigned Insn,
5137                                   uint64_t Address, const void *Decoder) {
5138   DecodeStatus S = MCDisassembler::Success;
5139   unsigned Rt  = fieldFromInstruction(Insn, 12, 4);
5140   unsigned Rt2 = fieldFromInstruction(Insn, 16, 4);
5141   unsigned Rm  = fieldFromInstruction(Insn,  5, 1);
5142   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5143   Rm |= fieldFromInstruction(Insn, 0, 4) << 1;
5144 
5145   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
5146     S = MCDisassembler::SoftFail;
5147 
5148   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
5149     return MCDisassembler::Fail;
5150   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
5151     return MCDisassembler::Fail;
5152   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
5153     return MCDisassembler::Fail;
5154   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
5155     return MCDisassembler::Fail;
5156   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5157     return MCDisassembler::Fail;
5158 
5159   return S;
5160 }
5161 
5162 static DecodeStatus DecodeIT(MCInst &Inst, unsigned Insn,
5163                              uint64_t Address, const void *Decoder) {
5164   DecodeStatus S = MCDisassembler::Success;
5165   unsigned pred = fieldFromInstruction(Insn, 4, 4);
5166   unsigned mask = fieldFromInstruction(Insn, 0, 4);
5167 
5168   if (pred == 0xF) {
5169     pred = 0xE;
5170     S = MCDisassembler::SoftFail;
5171   }
5172 
5173   if (mask == 0x0)
5174     return MCDisassembler::Fail;
5175 
5176   // IT masks are encoded as a sequence of replacement low-order bits
5177   // for the condition code. So if the low bit of the starting
5178   // condition code is 1, then we have to flip all the bits above the
5179   // terminating bit (which is the lowest 1 bit).
5180   if (pred & 1) {
5181     unsigned LowBit = mask & -mask;
5182     unsigned BitsAboveLowBit = 0xF & (-LowBit << 1);
5183     mask ^= BitsAboveLowBit;
5184   }
5185 
5186   Inst.addOperand(MCOperand::createImm(pred));
5187   Inst.addOperand(MCOperand::createImm(mask));
5188   return S;
5189 }
5190 
5191 static DecodeStatus
5192 DecodeT2LDRDPreInstruction(MCInst &Inst, unsigned Insn,
5193                            uint64_t Address, const void *Decoder) {
5194   DecodeStatus S = MCDisassembler::Success;
5195 
5196   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5197   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5198   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5199   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5200   unsigned W = fieldFromInstruction(Insn, 21, 1);
5201   unsigned U = fieldFromInstruction(Insn, 23, 1);
5202   unsigned P = fieldFromInstruction(Insn, 24, 1);
5203   bool writeback = (W == 1) | (P == 0);
5204 
5205   addr |= (U << 8) | (Rn << 9);
5206 
5207   if (writeback && (Rn == Rt || Rn == Rt2))
5208     Check(S, MCDisassembler::SoftFail);
5209   if (Rt == Rt2)
5210     Check(S, MCDisassembler::SoftFail);
5211 
5212   // Rt
5213   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5214     return MCDisassembler::Fail;
5215   // Rt2
5216   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5217     return MCDisassembler::Fail;
5218   // Writeback operand
5219   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5220     return MCDisassembler::Fail;
5221   // addr
5222   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5223     return MCDisassembler::Fail;
5224 
5225   return S;
5226 }
5227 
5228 static DecodeStatus
5229 DecodeT2STRDPreInstruction(MCInst &Inst, unsigned Insn,
5230                            uint64_t Address, const void *Decoder) {
5231   DecodeStatus S = MCDisassembler::Success;
5232 
5233   unsigned Rt = fieldFromInstruction(Insn, 12, 4);
5234   unsigned Rt2 = fieldFromInstruction(Insn, 8, 4);
5235   unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5236   unsigned addr = fieldFromInstruction(Insn, 0, 8);
5237   unsigned W = fieldFromInstruction(Insn, 21, 1);
5238   unsigned U = fieldFromInstruction(Insn, 23, 1);
5239   unsigned P = fieldFromInstruction(Insn, 24, 1);
5240   bool writeback = (W == 1) | (P == 0);
5241 
5242   addr |= (U << 8) | (Rn << 9);
5243 
5244   if (writeback && (Rn == Rt || Rn == Rt2))
5245     Check(S, MCDisassembler::SoftFail);
5246 
5247   // Writeback operand
5248   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
5249     return MCDisassembler::Fail;
5250   // Rt
5251   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
5252     return MCDisassembler::Fail;
5253   // Rt2
5254   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
5255     return MCDisassembler::Fail;
5256   // addr
5257   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
5258     return MCDisassembler::Fail;
5259 
5260   return S;
5261 }
5262 
5263 static DecodeStatus DecodeT2Adr(MCInst &Inst, uint32_t Insn,
5264                                 uint64_t Address, const void *Decoder) {
5265   unsigned sign1 = fieldFromInstruction(Insn, 21, 1);
5266   unsigned sign2 = fieldFromInstruction(Insn, 23, 1);
5267   if (sign1 != sign2) return MCDisassembler::Fail;
5268 
5269   unsigned Val = fieldFromInstruction(Insn, 0, 8);
5270   Val |= fieldFromInstruction(Insn, 12, 3) << 8;
5271   Val |= fieldFromInstruction(Insn, 26, 1) << 11;
5272   Val |= sign1 << 12;
5273   Inst.addOperand(MCOperand::createImm(SignExtend32<13>(Val)));
5274 
5275   return MCDisassembler::Success;
5276 }
5277 
5278 static DecodeStatus DecodeT2ShifterImmOperand(MCInst &Inst, uint32_t Val,
5279                                               uint64_t Address,
5280                                               const void *Decoder) {
5281   DecodeStatus S = MCDisassembler::Success;
5282 
5283   // Shift of "asr #32" is not allowed in Thumb2 mode.
5284   if (Val == 0x20) S = MCDisassembler::Fail;
5285   Inst.addOperand(MCOperand::createImm(Val));
5286   return S;
5287 }
5288 
5289 static DecodeStatus DecodeSwap(MCInst &Inst, unsigned Insn,
5290                                uint64_t Address, const void *Decoder) {
5291   unsigned Rt   = fieldFromInstruction(Insn, 12, 4);
5292   unsigned Rt2  = fieldFromInstruction(Insn, 0,  4);
5293   unsigned Rn   = fieldFromInstruction(Insn, 16, 4);
5294   unsigned pred = fieldFromInstruction(Insn, 28, 4);
5295 
5296   if (pred == 0xF)
5297     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
5298 
5299   DecodeStatus S = MCDisassembler::Success;
5300 
5301   if (Rt == Rn || Rn == Rt2)
5302     S = MCDisassembler::SoftFail;
5303 
5304   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5305     return MCDisassembler::Fail;
5306   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5307     return MCDisassembler::Fail;
5308   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5309     return MCDisassembler::Fail;
5310   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5311     return MCDisassembler::Fail;
5312 
5313   return S;
5314 }
5315 
5316 static DecodeStatus DecodeVCVTD(MCInst &Inst, unsigned Insn,
5317                                 uint64_t Address, const void *Decoder) {
5318   const FeatureBitset &featureBits =
5319       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5320   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5321 
5322   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5323   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5324   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5325   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5326   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5327   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5328   unsigned op = fieldFromInstruction(Insn, 5, 1);
5329 
5330   DecodeStatus S = MCDisassembler::Success;
5331 
5332   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5333   if (!(imm & 0x38)) {
5334     if (cmode == 0xF) {
5335       if (op == 1) return MCDisassembler::Fail;
5336       Inst.setOpcode(ARM::VMOVv2f32);
5337     }
5338     if (hasFullFP16) {
5339       if (cmode == 0xE) {
5340         if (op == 1) {
5341           Inst.setOpcode(ARM::VMOVv1i64);
5342         } else {
5343           Inst.setOpcode(ARM::VMOVv8i8);
5344         }
5345       }
5346       if (cmode == 0xD) {
5347         if (op == 1) {
5348           Inst.setOpcode(ARM::VMVNv2i32);
5349         } else {
5350           Inst.setOpcode(ARM::VMOVv2i32);
5351         }
5352       }
5353       if (cmode == 0xC) {
5354         if (op == 1) {
5355           Inst.setOpcode(ARM::VMVNv2i32);
5356         } else {
5357           Inst.setOpcode(ARM::VMOVv2i32);
5358         }
5359       }
5360     }
5361     return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
5362   }
5363 
5364   if (!(imm & 0x20)) return MCDisassembler::Fail;
5365 
5366   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
5367     return MCDisassembler::Fail;
5368   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5369     return MCDisassembler::Fail;
5370   Inst.addOperand(MCOperand::createImm(64 - imm));
5371 
5372   return S;
5373 }
5374 
5375 static DecodeStatus DecodeVCVTQ(MCInst &Inst, unsigned Insn,
5376                                 uint64_t Address, const void *Decoder) {
5377   const FeatureBitset &featureBits =
5378       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5379   bool hasFullFP16 = featureBits[ARM::FeatureFullFP16];
5380 
5381   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5382   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5383   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5384   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5385   unsigned imm = fieldFromInstruction(Insn, 16, 6);
5386   unsigned cmode = fieldFromInstruction(Insn, 8, 4);
5387   unsigned op = fieldFromInstruction(Insn, 5, 1);
5388 
5389   DecodeStatus S = MCDisassembler::Success;
5390 
5391   // If the top 3 bits of imm are clear, this is a VMOV (immediate)
5392   if (!(imm & 0x38)) {
5393     if (cmode == 0xF) {
5394       if (op == 1) return MCDisassembler::Fail;
5395       Inst.setOpcode(ARM::VMOVv4f32);
5396     }
5397     if (hasFullFP16) {
5398       if (cmode == 0xE) {
5399         if (op == 1) {
5400           Inst.setOpcode(ARM::VMOVv2i64);
5401         } else {
5402           Inst.setOpcode(ARM::VMOVv16i8);
5403         }
5404       }
5405       if (cmode == 0xD) {
5406         if (op == 1) {
5407           Inst.setOpcode(ARM::VMVNv4i32);
5408         } else {
5409           Inst.setOpcode(ARM::VMOVv4i32);
5410         }
5411       }
5412       if (cmode == 0xC) {
5413         if (op == 1) {
5414           Inst.setOpcode(ARM::VMVNv4i32);
5415         } else {
5416           Inst.setOpcode(ARM::VMOVv4i32);
5417         }
5418       }
5419     }
5420     return DecodeNEONModImmInstruction(Inst, Insn, Address, Decoder);
5421   }
5422 
5423   if (!(imm & 0x20)) return MCDisassembler::Fail;
5424 
5425   if (!Check(S, DecodeQPRRegisterClass(Inst, Vd, Address, Decoder)))
5426     return MCDisassembler::Fail;
5427   if (!Check(S, DecodeQPRRegisterClass(Inst, Vm, Address, Decoder)))
5428     return MCDisassembler::Fail;
5429   Inst.addOperand(MCOperand::createImm(64 - imm));
5430 
5431   return S;
5432 }
5433 
5434 static DecodeStatus DecodeNEONComplexLane64Instruction(MCInst &Inst,
5435                                                        unsigned Insn,
5436                                                        uint64_t Address,
5437                                                        const void *Decoder) {
5438   unsigned Vd = (fieldFromInstruction(Insn, 12, 4) << 0);
5439   Vd |= (fieldFromInstruction(Insn, 22, 1) << 4);
5440   unsigned Vn = (fieldFromInstruction(Insn, 16, 4) << 0);
5441   Vn |= (fieldFromInstruction(Insn, 7, 1) << 4);
5442   unsigned Vm = (fieldFromInstruction(Insn, 0, 4) << 0);
5443   Vm |= (fieldFromInstruction(Insn, 5, 1) << 4);
5444   unsigned q = (fieldFromInstruction(Insn, 6, 1) << 0);
5445   unsigned rotate = (fieldFromInstruction(Insn, 20, 2) << 0);
5446 
5447   DecodeStatus S = MCDisassembler::Success;
5448 
5449   auto DestRegDecoder = q ? DecodeQPRRegisterClass : DecodeDPRRegisterClass;
5450 
5451   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5452     return MCDisassembler::Fail;
5453   if (!Check(S, DestRegDecoder(Inst, Vd, Address, Decoder)))
5454     return MCDisassembler::Fail;
5455   if (!Check(S, DestRegDecoder(Inst, Vn, Address, Decoder)))
5456     return MCDisassembler::Fail;
5457   if (!Check(S, DecodeDPRRegisterClass(Inst, Vm, Address, Decoder)))
5458     return MCDisassembler::Fail;
5459   // The lane index does not have any bits in the encoding, because it can only
5460   // be 0.
5461   Inst.addOperand(MCOperand::createImm(0));
5462   Inst.addOperand(MCOperand::createImm(rotate));
5463 
5464   return S;
5465 }
5466 
5467 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
5468                                 uint64_t Address, const void *Decoder) {
5469   DecodeStatus S = MCDisassembler::Success;
5470 
5471   unsigned Rn = fieldFromInstruction(Val, 16, 4);
5472   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5473   unsigned Rm = fieldFromInstruction(Val, 0, 4);
5474   Rm |= (fieldFromInstruction(Val, 23, 1) << 4);
5475   unsigned Cond = fieldFromInstruction(Val, 28, 4);
5476 
5477   if (fieldFromInstruction(Val, 8, 4) != 0 || Rn == Rt)
5478     S = MCDisassembler::SoftFail;
5479 
5480   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5481     return MCDisassembler::Fail;
5482   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5483     return MCDisassembler::Fail;
5484   if (!Check(S, DecodeAddrMode7Operand(Inst, Rn, Address, Decoder)))
5485     return MCDisassembler::Fail;
5486   if (!Check(S, DecodePostIdxReg(Inst, Rm, Address, Decoder)))
5487     return MCDisassembler::Fail;
5488   if (!Check(S, DecodePredicateOperand(Inst, Cond, Address, Decoder)))
5489     return MCDisassembler::Fail;
5490 
5491   return S;
5492 }
5493 
5494 static DecodeStatus DecoderForMRRC2AndMCRR2(MCInst &Inst, unsigned Val,
5495                                             uint64_t Address, const void *Decoder) {
5496   DecodeStatus S = MCDisassembler::Success;
5497 
5498   unsigned CRm = fieldFromInstruction(Val, 0, 4);
5499   unsigned opc1 = fieldFromInstruction(Val, 4, 4);
5500   unsigned cop = fieldFromInstruction(Val, 8, 4);
5501   unsigned Rt = fieldFromInstruction(Val, 12, 4);
5502   unsigned Rt2 = fieldFromInstruction(Val, 16, 4);
5503 
5504   if ((cop & ~0x1) == 0xa)
5505     return MCDisassembler::Fail;
5506 
5507   if (Rt == Rt2)
5508     S = MCDisassembler::SoftFail;
5509 
5510   // We have to check if the instruction is MRRC2
5511   // or MCRR2 when constructing the operands for
5512   // Inst. Reason is because MRRC2 stores to two
5513   // registers so it's tablegen desc has has two
5514   // outputs whereas MCRR doesn't store to any
5515   // registers so all of it's operands are listed
5516   // as inputs, therefore the operand order for
5517   // MRRC2 needs to be [Rt, Rt2, cop, opc1, CRm]
5518   // and MCRR2 operand order is [cop, opc1, Rt, Rt2, CRm]
5519 
5520   if (Inst.getOpcode() == ARM::MRRC2) {
5521     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5522       return MCDisassembler::Fail;
5523     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5524       return MCDisassembler::Fail;
5525   }
5526   Inst.addOperand(MCOperand::createImm(cop));
5527   Inst.addOperand(MCOperand::createImm(opc1));
5528   if (Inst.getOpcode() == ARM::MCRR2) {
5529     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
5530       return MCDisassembler::Fail;
5531     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
5532       return MCDisassembler::Fail;
5533   }
5534   Inst.addOperand(MCOperand::createImm(CRm));
5535 
5536   return S;
5537 }
5538 
5539 static DecodeStatus DecodeForVMRSandVMSR(MCInst &Inst, unsigned Val,
5540                                          uint64_t Address,
5541                                          const void *Decoder) {
5542   const FeatureBitset &featureBits =
5543       ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5544   DecodeStatus S = MCDisassembler::Success;
5545 
5546   // Add explicit operand for the destination sysreg, for cases where
5547   // we have to model it for code generation purposes.
5548   switch (Inst.getOpcode()) {
5549   case ARM::VMSR_FPSCR_NZCVQC:
5550     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5551     break;
5552   case ARM::VMSR_P0:
5553     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5554     break;
5555   }
5556 
5557   if (Inst.getOpcode() != ARM::FMSTAT) {
5558     unsigned Rt = fieldFromInstruction(Val, 12, 4);
5559 
5560     if (featureBits[ARM::ModeThumb] && !featureBits[ARM::HasV8Ops]) {
5561       if (Rt == 13 || Rt == 15)
5562         S = MCDisassembler::SoftFail;
5563       Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
5564     } else
5565       Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder));
5566   }
5567 
5568   // Add explicit operand for the source sysreg, similarly to above.
5569   switch (Inst.getOpcode()) {
5570   case ARM::VMRS_FPSCR_NZCVQC:
5571     Inst.addOperand(MCOperand::createReg(ARM::FPSCR_NZCV));
5572     break;
5573   case ARM::VMRS_P0:
5574     Inst.addOperand(MCOperand::createReg(ARM::VPR));
5575     break;
5576   }
5577 
5578   if (featureBits[ARM::ModeThumb]) {
5579     Inst.addOperand(MCOperand::createImm(ARMCC::AL));
5580     Inst.addOperand(MCOperand::createReg(0));
5581   } else {
5582     unsigned pred = fieldFromInstruction(Val, 28, 4);
5583     if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
5584       return MCDisassembler::Fail;
5585   }
5586 
5587   return S;
5588 }
5589 
5590 template <bool isSigned, bool isNeg, int size>
5591 static DecodeStatus DecodeBFLabelOperand(MCInst &Inst, unsigned Val,
5592                                          uint64_t Address,
5593                                          const void *Decoder) {
5594   DecodeStatus S = MCDisassembler::Success;
5595   if (Val == 0)
5596     S = MCDisassembler::SoftFail;
5597 
5598   uint64_t DecVal;
5599   if (isSigned)
5600     DecVal = SignExtend32<size + 1>(Val << 1);
5601   else
5602     DecVal = (Val << 1);
5603 
5604   if (!tryAddingSymbolicOperand(Address, Address + DecVal + 4, true, 4, Inst,
5605                                 Decoder))
5606     Inst.addOperand(MCOperand::createImm(isNeg ? -DecVal : DecVal));
5607   return S;
5608 }
5609 
5610 static DecodeStatus DecodeBFAfterTargetOperand(MCInst &Inst, unsigned Val,
5611                                                uint64_t Address,
5612                                                const void *Decoder) {
5613 
5614   uint64_t LocImm = Inst.getOperand(0).getImm();
5615   Val = LocImm + (2 << Val);
5616   if (!tryAddingSymbolicOperand(Address, Address + Val + 4, true, 4, Inst,
5617                                 Decoder))
5618     Inst.addOperand(MCOperand::createImm(Val));
5619   return MCDisassembler::Success;
5620 }
5621 
5622 static DecodeStatus DecodePredNoALOperand(MCInst &Inst, unsigned Val,
5623                                           uint64_t Address,
5624                                           const void *Decoder) {
5625   if (Val >= ARMCC::AL)  // also exclude the non-condition NV
5626     return MCDisassembler::Fail;
5627   Inst.addOperand(MCOperand::createImm(Val));
5628   return MCDisassembler::Success;
5629 }
5630 
5631 static DecodeStatus DecodeLOLoop(MCInst &Inst, unsigned Insn, uint64_t Address,
5632                                  const void *Decoder) {
5633   DecodeStatus S = MCDisassembler::Success;
5634 
5635   unsigned Imm = fieldFromInstruction(Insn, 11, 1) |
5636                  fieldFromInstruction(Insn, 1, 10) << 1;
5637   switch (Inst.getOpcode()) {
5638   case ARM::t2LEUpdate:
5639     Inst.addOperand(MCOperand::createReg(ARM::LR));
5640     Inst.addOperand(MCOperand::createReg(ARM::LR));
5641     LLVM_FALLTHROUGH;
5642   case ARM::t2LE:
5643     if (!Check(S, DecodeBFLabelOperand<false, true, 11>(Inst, Imm, Address,
5644                                                         Decoder)))
5645       return MCDisassembler::Fail;
5646     break;
5647   case ARM::t2WLS:
5648     Inst.addOperand(MCOperand::createReg(ARM::LR));
5649     if (!Check(S,
5650                DecoderGPRRegisterClass(Inst, fieldFromInstruction(Insn, 16, 4),
5651                                        Address, Decoder)) ||
5652         !Check(S, DecodeBFLabelOperand<false, false, 11>(Inst, Imm, Address,
5653                                                          Decoder)))
5654       return MCDisassembler::Fail;
5655     break;
5656   case ARM::t2DLS:
5657     unsigned Rn = fieldFromInstruction(Insn, 16, 4);
5658     if (Rn == 0xF) {
5659       return MCDisassembler::Fail;
5660     } else {
5661       Inst.addOperand(MCOperand::createReg(ARM::LR));
5662       if (!Check(S, DecoderGPRRegisterClass(Inst,
5663                                             fieldFromInstruction(Insn, 16, 4),
5664                                             Address, Decoder)))
5665         return MCDisassembler::Fail;
5666     }
5667     break;
5668   }
5669   return S;
5670 }
5671 
5672 static DecodeStatus DecodeLongShiftOperand(MCInst &Inst, unsigned Val,
5673                                            uint64_t Address,
5674                                            const void *Decoder) {
5675   DecodeStatus S = MCDisassembler::Success;
5676 
5677   if (Val == 0)
5678     Val = 32;
5679 
5680   Inst.addOperand(MCOperand::createImm(Val));
5681 
5682   return S;
5683 }
5684 
5685 static DecodeStatus DecodetGPROddRegisterClass(MCInst &Inst, unsigned RegNo,
5686                                    uint64_t Address, const void *Decoder) {
5687   if ((RegNo) + 1 > 11)
5688     return MCDisassembler::Fail;
5689 
5690   unsigned Register = GPRDecoderTable[(RegNo) + 1];
5691   Inst.addOperand(MCOperand::createReg(Register));
5692   return MCDisassembler::Success;
5693 }
5694 
5695 static DecodeStatus DecodetGPREvenRegisterClass(MCInst &Inst, unsigned RegNo,
5696                                    uint64_t Address, const void *Decoder) {
5697   if ((RegNo) > 14)
5698     return MCDisassembler::Fail;
5699 
5700   unsigned Register = GPRDecoderTable[(RegNo)];
5701   Inst.addOperand(MCOperand::createReg(Register));
5702   return MCDisassembler::Success;
5703 }
5704 
5705 static DecodeStatus DecodeVSCCLRM(MCInst &Inst, unsigned Insn, uint64_t Address,
5706                                   const void *Decoder) {
5707   DecodeStatus S = MCDisassembler::Success;
5708 
5709   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
5710   Inst.addOperand(MCOperand::createReg(0));
5711   if (Inst.getOpcode() == ARM::VSCCLRMD) {
5712     unsigned reglist = (fieldFromInstruction(Insn, 1, 7) << 1) |
5713                        (fieldFromInstruction(Insn, 12, 4) << 8) |
5714                        (fieldFromInstruction(Insn, 22, 1) << 12);
5715     if (!Check(S, DecodeDPRRegListOperand(Inst, reglist, Address, Decoder))) {
5716       return MCDisassembler::Fail;
5717     }
5718   } else {
5719     unsigned reglist = fieldFromInstruction(Insn, 0, 8) |
5720                        (fieldFromInstruction(Insn, 22, 1) << 8) |
5721                        (fieldFromInstruction(Insn, 12, 4) << 9);
5722     if (!Check(S, DecodeSPRRegListOperand(Inst, reglist, Address, Decoder))) {
5723       return MCDisassembler::Fail;
5724     }
5725   }
5726   Inst.addOperand(MCOperand::createReg(ARM::VPR));
5727 
5728   return S;
5729 }
5730 
5731 static unsigned FixedRegForVSTRVLDR_SYSREG(unsigned Opcode) {
5732   switch (Opcode) {
5733   case ARM::VSTR_P0_off:
5734   case ARM::VSTR_P0_pre:
5735   case ARM::VSTR_P0_post:
5736   case ARM::VLDR_P0_off:
5737   case ARM::VLDR_P0_pre:
5738   case ARM::VLDR_P0_post:
5739     return ARM::P0;
5740   default:
5741     return 0;
5742   }
5743 }
5744 
5745 template<bool Writeback>
5746 static DecodeStatus DecodeVSTRVLDR_SYSREG(MCInst &Inst, unsigned Val,
5747                                           uint64_t Address,
5748                                           const void *Decoder) {
5749   switch (Inst.getOpcode()) {
5750   case ARM::VSTR_FPSCR_pre:
5751   case ARM::VSTR_FPSCR_NZCVQC_pre:
5752   case ARM::VLDR_FPSCR_pre:
5753   case ARM::VLDR_FPSCR_NZCVQC_pre:
5754   case ARM::VSTR_FPSCR_off:
5755   case ARM::VSTR_FPSCR_NZCVQC_off:
5756   case ARM::VLDR_FPSCR_off:
5757   case ARM::VLDR_FPSCR_NZCVQC_off:
5758   case ARM::VSTR_FPSCR_post:
5759   case ARM::VSTR_FPSCR_NZCVQC_post:
5760   case ARM::VLDR_FPSCR_post:
5761   case ARM::VLDR_FPSCR_NZCVQC_post:
5762     const FeatureBitset &featureBits =
5763         ((const MCDisassembler *)Decoder)->getSubtargetInfo().getFeatureBits();
5764 
5765     if (!featureBits[ARM::HasMVEIntegerOps] && !featureBits[ARM::FeatureVFP2])
5766       return MCDisassembler::Fail;
5767   }
5768 
5769   DecodeStatus S = MCDisassembler::Success;
5770   if (unsigned Sysreg = FixedRegForVSTRVLDR_SYSREG(Inst.getOpcode()))
5771     Inst.addOperand(MCOperand::createReg(Sysreg));
5772   unsigned Rn = fieldFromInstruction(Val, 16, 4);
5773   unsigned addr = fieldFromInstruction(Val, 0, 7) |
5774                   (fieldFromInstruction(Val, 23, 1) << 7) | (Rn << 8);
5775 
5776   if (Writeback) {
5777     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
5778       return MCDisassembler::Fail;
5779   }
5780   if (!Check(S, DecodeT2AddrModeImm7s4(Inst, addr, Address, Decoder)))
5781     return MCDisassembler::Fail;
5782 
5783   Inst.addOperand(MCOperand::createImm(ARMCC::AL));
5784   Inst.addOperand(MCOperand::createReg(0));
5785 
5786   return S;
5787 }
5788 
5789 static DecodeStatus DecodeMVEOverlappingLongShift(
5790   MCInst &Inst, unsigned Insn, uint64_t Address, const void *Decoder) {
5791   DecodeStatus S = MCDisassembler::Success;
5792 
5793   unsigned RdaLo = fieldFromInstruction(Insn, 17, 3) << 1;
5794   unsigned RdaHi = fieldFromInstruction(Insn, 9, 3) << 1;
5795   unsigned Rm = fieldFromInstruction(Insn, 12, 4);
5796 
5797   if (RdaHi == 14) {
5798     // This value of RdaHi (really indicating pc, because RdaHi has to
5799     // be an odd-numbered register, so the low bit will be set by the
5800     // decode function below) indicates that we must decode as SQRSHR
5801     // or UQRSHL, which both have a single Rda register field with all
5802     // four bits.
5803     unsigned Rda = fieldFromInstruction(Insn, 16, 4);
5804 
5805     switch (Inst.getOpcode()) {
5806       case ARM::t2ASRLr:
5807       case ARM::t2SQRSHRL:
5808         Inst.setOpcode(ARM::t2SQRSHR);
5809         break;
5810       case ARM::t2LSLLr:
5811       case ARM::t2UQRSHLL:
5812         Inst.setOpcode(ARM::t2UQRSHL);
5813         break;
5814       default:
5815         llvm_unreachable("Unexpected starting opcode!");
5816     }
5817 
5818     // Rda as output parameter
5819     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
5820       return MCDisassembler::Fail;
5821 
5822     // Rda again as input parameter
5823     if (!Check(S, DecoderGPRRegisterClass(Inst, Rda, Address, Decoder)))
5824       return MCDisassembler::Fail;
5825 
5826     // Rm, the amount to shift by
5827     if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
5828       return MCDisassembler::Fail;
5829 
5830     return S;
5831   }
5832 
5833   // Otherwise, we decode as whichever opcode our caller has already
5834   // put into Inst. Those all look the same:
5835 
5836   // RdaLo,RdaHi as output parameters
5837   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
5838     return MCDisassembler::Fail;
5839   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
5840     return MCDisassembler::Fail;
5841 
5842   // RdaLo,RdaHi again as input parameters
5843   if (!Check(S, DecodetGPREvenRegisterClass(Inst, RdaLo, Address, Decoder)))
5844     return MCDisassembler::Fail;
5845   if (!Check(S, DecodetGPROddRegisterClass(Inst, RdaHi, Address, Decoder)))
5846     return MCDisassembler::Fail;
5847 
5848   // Rm, the amount to shift by
5849   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
5850     return MCDisassembler::Fail;
5851 
5852   return S;
5853 }
5854