xref: /llvm-project/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (revision 6a5c150e9cefdf2368ac4f6a45cc7d914887ed10)
1 //===- ARMDisassembler.cpp - Disassembler for ARM/Thumb ISA -----*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #define DEBUG_TYPE "arm-disassembler"
11 
12 #include "ARM.h"
13 #include "ARMRegisterInfo.h"
14 #include "ARMSubtarget.h"
15 #include "MCTargetDesc/ARMAddressingModes.h"
16 #include "MCTargetDesc/ARMMCExpr.h"
17 #include "MCTargetDesc/ARMBaseInfo.h"
18 #include "llvm/MC/EDInstInfo.h"
19 #include "llvm/MC/MCInst.h"
20 #include "llvm/MC/MCExpr.h"
21 #include "llvm/MC/MCContext.h"
22 #include "llvm/MC/MCDisassembler.h"
23 #include "llvm/Support/Debug.h"
24 #include "llvm/Support/MemoryObject.h"
25 #include "llvm/Support/ErrorHandling.h"
26 #include "llvm/Support/TargetRegistry.h"
27 #include "llvm/Support/raw_ostream.h"
28 
29 using namespace llvm;
30 
31 typedef MCDisassembler::DecodeStatus DecodeStatus;
32 
33 namespace {
34 /// ARMDisassembler - ARM disassembler for all ARM platforms.
35 class ARMDisassembler : public MCDisassembler {
36 public:
37   /// Constructor     - Initializes the disassembler.
38   ///
39   ARMDisassembler(const MCSubtargetInfo &STI) :
40     MCDisassembler(STI) {
41   }
42 
43   ~ARMDisassembler() {
44   }
45 
46   /// getInstruction - See MCDisassembler.
47   DecodeStatus getInstruction(MCInst &instr,
48                               uint64_t &size,
49                               const MemoryObject &region,
50                               uint64_t address,
51                               raw_ostream &vStream,
52                               raw_ostream &cStream) const;
53 
54   /// getEDInfo - See MCDisassembler.
55   EDInstInfo *getEDInfo() const;
56 private:
57 };
58 
59 /// ThumbDisassembler - Thumb disassembler for all Thumb platforms.
60 class ThumbDisassembler : public MCDisassembler {
61 public:
62   /// Constructor     - Initializes the disassembler.
63   ///
64   ThumbDisassembler(const MCSubtargetInfo &STI) :
65     MCDisassembler(STI) {
66   }
67 
68   ~ThumbDisassembler() {
69   }
70 
71   /// getInstruction - See MCDisassembler.
72   DecodeStatus getInstruction(MCInst &instr,
73                               uint64_t &size,
74                               const MemoryObject &region,
75                               uint64_t address,
76                               raw_ostream &vStream,
77                               raw_ostream &cStream) const;
78 
79   /// getEDInfo - See MCDisassembler.
80   EDInstInfo *getEDInfo() const;
81 private:
82   mutable std::vector<unsigned> ITBlock;
83   DecodeStatus AddThumbPredicate(MCInst&) const;
84   void UpdateThumbVFPPredicate(MCInst&) const;
85 };
86 }
87 
88 static bool Check(DecodeStatus &Out, DecodeStatus In) {
89   switch (In) {
90     case MCDisassembler::Success:
91       // Out stays the same.
92       return true;
93     case MCDisassembler::SoftFail:
94       Out = In;
95       return true;
96     case MCDisassembler::Fail:
97       Out = In;
98       return false;
99   }
100   return false;
101 }
102 
103 
104 // Forward declare these because the autogenerated code will reference them.
105 // Definitions are further down.
106 static DecodeStatus DecodeGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
107                                    uint64_t Address, const void *Decoder);
108 static DecodeStatus DecodeGPRnopcRegisterClass(llvm::MCInst &Inst,
109                                                unsigned RegNo, uint64_t Address,
110                                                const void *Decoder);
111 static DecodeStatus DecodetGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
112                                    uint64_t Address, const void *Decoder);
113 static DecodeStatus DecodetcGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
114                                    uint64_t Address, const void *Decoder);
115 static DecodeStatus DecoderGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
116                                    uint64_t Address, const void *Decoder);
117 static DecodeStatus DecodeSPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
118                                    uint64_t Address, const void *Decoder);
119 static DecodeStatus DecodeDPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
120                                    uint64_t Address, const void *Decoder);
121 static DecodeStatus DecodeDPR_8RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
122                                    uint64_t Address, const void *Decoder);
123 static DecodeStatus DecodeDPR_VFP2RegisterClass(llvm::MCInst &Inst,
124                                                 unsigned RegNo,
125                                                 uint64_t Address,
126                                                 const void *Decoder);
127 static DecodeStatus DecodeQPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
128                                    uint64_t Address, const void *Decoder);
129 
130 static DecodeStatus DecodePredicateOperand(llvm::MCInst &Inst, unsigned Val,
131                                uint64_t Address, const void *Decoder);
132 static DecodeStatus DecodeCCOutOperand(llvm::MCInst &Inst, unsigned Val,
133                                uint64_t Address, const void *Decoder);
134 static DecodeStatus DecodeSOImmOperand(llvm::MCInst &Inst, unsigned Val,
135                                uint64_t Address, const void *Decoder);
136 static DecodeStatus DecodeRegListOperand(llvm::MCInst &Inst, unsigned Val,
137                                uint64_t Address, const void *Decoder);
138 static DecodeStatus DecodeSPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
139                                uint64_t Address, const void *Decoder);
140 static DecodeStatus DecodeDPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
141                                uint64_t Address, const void *Decoder);
142 
143 static DecodeStatus DecodeBitfieldMaskOperand(llvm::MCInst &Inst, unsigned Insn,
144                                uint64_t Address, const void *Decoder);
145 static DecodeStatus DecodeCopMemInstruction(llvm::MCInst &Inst, unsigned Insn,
146                                uint64_t Address, const void *Decoder);
147 static DecodeStatus DecodeAddrMode2IdxInstruction(llvm::MCInst &Inst,
148                                                   unsigned Insn,
149                                                   uint64_t Address,
150                                                   const void *Decoder);
151 static DecodeStatus DecodeSORegMemOperand(llvm::MCInst &Inst, unsigned Insn,
152                                uint64_t Address, const void *Decoder);
153 static DecodeStatus DecodeAddrMode3Instruction(llvm::MCInst &Inst,unsigned Insn,
154                                uint64_t Address, const void *Decoder);
155 static DecodeStatus DecodeSORegImmOperand(llvm::MCInst &Inst, unsigned Insn,
156                                uint64_t Address, const void *Decoder);
157 static DecodeStatus DecodeSORegRegOperand(llvm::MCInst &Inst, unsigned Insn,
158                                uint64_t Address, const void *Decoder);
159 
160 static DecodeStatus DecodeMemMultipleWritebackInstruction(llvm::MCInst & Inst,
161                                                   unsigned Insn,
162                                                   uint64_t Adddress,
163                                                   const void *Decoder);
164 static DecodeStatus DecodeT2MOVTWInstruction(llvm::MCInst &Inst, unsigned Insn,
165                                uint64_t Address, const void *Decoder);
166 static DecodeStatus DecodeArmMOVTWInstruction(llvm::MCInst &Inst, unsigned Insn,
167                                uint64_t Address, const void *Decoder);
168 static DecodeStatus DecodeSMLAInstruction(llvm::MCInst &Inst, unsigned Insn,
169                                uint64_t Address, const void *Decoder);
170 static DecodeStatus DecodeCPSInstruction(llvm::MCInst &Inst, unsigned Insn,
171                                uint64_t Address, const void *Decoder);
172 static DecodeStatus DecodeT2CPSInstruction(llvm::MCInst &Inst, unsigned Insn,
173                                uint64_t Address, const void *Decoder);
174 static DecodeStatus DecodeAddrModeImm12Operand(llvm::MCInst &Inst, unsigned Val,
175                                uint64_t Address, const void *Decoder);
176 static DecodeStatus DecodeAddrMode5Operand(llvm::MCInst &Inst, unsigned Val,
177                                uint64_t Address, const void *Decoder);
178 static DecodeStatus DecodeAddrMode7Operand(llvm::MCInst &Inst, unsigned Val,
179                                uint64_t Address, const void *Decoder);
180 static DecodeStatus DecodeBranchImmInstruction(llvm::MCInst &Inst,unsigned Insn,
181                                uint64_t Address, const void *Decoder);
182 static DecodeStatus DecodeVCVTImmOperand(llvm::MCInst &Inst, unsigned Val,
183                                uint64_t Address, const void *Decoder);
184 static DecodeStatus DecodeAddrMode6Operand(llvm::MCInst &Inst, unsigned Val,
185                                uint64_t Address, const void *Decoder);
186 static DecodeStatus DecodeVLDInstruction(llvm::MCInst &Inst, unsigned Val,
187                                uint64_t Address, const void *Decoder);
188 static DecodeStatus DecodeVSTInstruction(llvm::MCInst &Inst, unsigned Val,
189                                uint64_t Address, const void *Decoder);
190 static DecodeStatus DecodeVLD1DupInstruction(llvm::MCInst &Inst, unsigned Val,
191                                uint64_t Address, const void *Decoder);
192 static DecodeStatus DecodeVLD2DupInstruction(llvm::MCInst &Inst, unsigned Val,
193                                uint64_t Address, const void *Decoder);
194 static DecodeStatus DecodeVLD3DupInstruction(llvm::MCInst &Inst, unsigned Val,
195                                uint64_t Address, const void *Decoder);
196 static DecodeStatus DecodeVLD4DupInstruction(llvm::MCInst &Inst, unsigned Val,
197                                uint64_t Address, const void *Decoder);
198 static DecodeStatus DecodeNEONModImmInstruction(llvm::MCInst &Inst,unsigned Val,
199                                uint64_t Address, const void *Decoder);
200 static DecodeStatus DecodeVSHLMaxInstruction(llvm::MCInst &Inst, unsigned Val,
201                                uint64_t Address, const void *Decoder);
202 static DecodeStatus DecodeShiftRight8Imm(llvm::MCInst &Inst, unsigned Val,
203                                uint64_t Address, const void *Decoder);
204 static DecodeStatus DecodeShiftRight16Imm(llvm::MCInst &Inst, unsigned Val,
205                                uint64_t Address, const void *Decoder);
206 static DecodeStatus DecodeShiftRight32Imm(llvm::MCInst &Inst, unsigned Val,
207                                uint64_t Address, const void *Decoder);
208 static DecodeStatus DecodeShiftRight64Imm(llvm::MCInst &Inst, unsigned Val,
209                                uint64_t Address, const void *Decoder);
210 static DecodeStatus DecodeTBLInstruction(llvm::MCInst &Inst, unsigned Insn,
211                                uint64_t Address, const void *Decoder);
212 static DecodeStatus DecodePostIdxReg(llvm::MCInst &Inst, unsigned Insn,
213                                uint64_t Address, const void *Decoder);
214 static DecodeStatus DecodeCoprocessor(llvm::MCInst &Inst, unsigned Insn,
215                                uint64_t Address, const void *Decoder);
216 static DecodeStatus DecodeMemBarrierOption(llvm::MCInst &Inst, unsigned Insn,
217                                uint64_t Address, const void *Decoder);
218 static DecodeStatus DecodeMSRMask(llvm::MCInst &Inst, unsigned Insn,
219                                uint64_t Address, const void *Decoder);
220 static DecodeStatus DecodeDoubleRegLoad(llvm::MCInst &Inst, unsigned Insn,
221                                uint64_t Address, const void *Decoder);
222 static DecodeStatus DecodeDoubleRegStore(llvm::MCInst &Inst, unsigned Insn,
223                                uint64_t Address, const void *Decoder);
224 static DecodeStatus DecodeLDRPreImm(llvm::MCInst &Inst, unsigned Insn,
225                                uint64_t Address, const void *Decoder);
226 static DecodeStatus DecodeLDRPreReg(llvm::MCInst &Inst, unsigned Insn,
227                                uint64_t Address, const void *Decoder);
228 static DecodeStatus DecodeSTRPreImm(llvm::MCInst &Inst, unsigned Insn,
229                                uint64_t Address, const void *Decoder);
230 static DecodeStatus DecodeSTRPreReg(llvm::MCInst &Inst, unsigned Insn,
231                                uint64_t Address, const void *Decoder);
232 static DecodeStatus DecodeVLD1LN(llvm::MCInst &Inst, unsigned Insn,
233                                uint64_t Address, const void *Decoder);
234 static DecodeStatus DecodeVLD2LN(llvm::MCInst &Inst, unsigned Insn,
235                                uint64_t Address, const void *Decoder);
236 static DecodeStatus DecodeVLD3LN(llvm::MCInst &Inst, unsigned Insn,
237                                uint64_t Address, const void *Decoder);
238 static DecodeStatus DecodeVLD4LN(llvm::MCInst &Inst, unsigned Insn,
239                                uint64_t Address, const void *Decoder);
240 static DecodeStatus DecodeVST1LN(llvm::MCInst &Inst, unsigned Insn,
241                                uint64_t Address, const void *Decoder);
242 static DecodeStatus DecodeVST2LN(llvm::MCInst &Inst, unsigned Insn,
243                                uint64_t Address, const void *Decoder);
244 static DecodeStatus DecodeVST3LN(llvm::MCInst &Inst, unsigned Insn,
245                                uint64_t Address, const void *Decoder);
246 static DecodeStatus DecodeVST4LN(llvm::MCInst &Inst, unsigned Insn,
247                                uint64_t Address, const void *Decoder);
248 static DecodeStatus DecodeVMOVSRR(llvm::MCInst &Inst, unsigned Insn,
249                                uint64_t Address, const void *Decoder);
250 static DecodeStatus DecodeVMOVRRS(llvm::MCInst &Inst, unsigned Insn,
251                                uint64_t Address, const void *Decoder);
252 
253 static DecodeStatus DecodeThumbAddSpecialReg(llvm::MCInst &Inst, uint16_t Insn,
254                                uint64_t Address, const void *Decoder);
255 static DecodeStatus DecodeThumbBROperand(llvm::MCInst &Inst, unsigned Val,
256                                uint64_t Address, const void *Decoder);
257 static DecodeStatus DecodeT2BROperand(llvm::MCInst &Inst, unsigned Val,
258                                uint64_t Address, const void *Decoder);
259 static DecodeStatus DecodeThumbCmpBROperand(llvm::MCInst &Inst, unsigned Val,
260                                uint64_t Address, const void *Decoder);
261 static DecodeStatus DecodeThumbAddrModeRR(llvm::MCInst &Inst, unsigned Val,
262                                uint64_t Address, const void *Decoder);
263 static DecodeStatus DecodeThumbAddrModeIS(llvm::MCInst &Inst, unsigned Val,
264                                uint64_t Address, const void *Decoder);
265 static DecodeStatus DecodeThumbAddrModePC(llvm::MCInst &Inst, unsigned Val,
266                                uint64_t Address, const void *Decoder);
267 static DecodeStatus DecodeThumbAddrModeSP(llvm::MCInst &Inst, unsigned Val,
268                                uint64_t Address, const void *Decoder);
269 static DecodeStatus DecodeT2AddrModeSOReg(llvm::MCInst &Inst, unsigned Val,
270                                uint64_t Address, const void *Decoder);
271 static DecodeStatus DecodeT2LoadShift(llvm::MCInst &Inst, unsigned Val,
272                                uint64_t Address, const void *Decoder);
273 static DecodeStatus DecodeT2Imm8S4(llvm::MCInst &Inst, unsigned Val,
274                                uint64_t Address, const void *Decoder);
275 static DecodeStatus DecodeT2AddrModeImm8s4(llvm::MCInst &Inst, unsigned Val,
276                                uint64_t Address, const void *Decoder);
277 static DecodeStatus DecodeT2AddrModeImm0_1020s4(llvm::MCInst &Inst,unsigned Val,
278                                uint64_t Address, const void *Decoder);
279 static DecodeStatus DecodeT2Imm8(llvm::MCInst &Inst, unsigned Val,
280                                uint64_t Address, const void *Decoder);
281 static DecodeStatus DecodeT2AddrModeImm8(llvm::MCInst &Inst, unsigned Val,
282                                uint64_t Address, const void *Decoder);
283 static DecodeStatus DecodeThumbAddSPImm(llvm::MCInst &Inst, uint16_t Val,
284                                uint64_t Address, const void *Decoder);
285 static DecodeStatus DecodeThumbAddSPReg(llvm::MCInst &Inst, uint16_t Insn,
286                                 uint64_t Address, const void *Decoder);
287 static DecodeStatus DecodeThumbCPS(llvm::MCInst &Inst, uint16_t Insn,
288                                 uint64_t Address, const void *Decoder);
289 static DecodeStatus DecodeThumbBLXOffset(llvm::MCInst &Inst, unsigned Insn,
290                                 uint64_t Address, const void *Decoder);
291 static DecodeStatus DecodeT2AddrModeImm12(llvm::MCInst &Inst, unsigned Val,
292                                 uint64_t Address, const void *Decoder);
293 static DecodeStatus DecodeThumbTableBranch(llvm::MCInst &Inst, unsigned Val,
294                                 uint64_t Address, const void *Decoder);
295 static DecodeStatus DecodeThumb2BCCInstruction(llvm::MCInst &Inst, unsigned Val,
296                                 uint64_t Address, const void *Decoder);
297 static DecodeStatus DecodeT2SOImm(llvm::MCInst &Inst, unsigned Val,
298                                 uint64_t Address, const void *Decoder);
299 static DecodeStatus DecodeThumbBCCTargetOperand(llvm::MCInst &Inst,unsigned Val,
300                                 uint64_t Address, const void *Decoder);
301 static DecodeStatus DecodeThumbBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
302                                 uint64_t Address, const void *Decoder);
303 static DecodeStatus DecodeIT(llvm::MCInst &Inst, unsigned Val,
304                                 uint64_t Address, const void *Decoder);
305 static DecodeStatus DecodeT2LDRDPreInstruction(llvm::MCInst &Inst,unsigned Insn,
306                                uint64_t Address, const void *Decoder);
307 static DecodeStatus DecodeT2STRDPreInstruction(llvm::MCInst &Inst,unsigned Insn,
308                                uint64_t Address, const void *Decoder);
309 static DecodeStatus DecodeT2Adr(llvm::MCInst &Inst, unsigned Val,
310                                 uint64_t Address, const void *Decoder);
311 static DecodeStatus DecodeT2LdStPre(llvm::MCInst &Inst, unsigned Val,
312                                 uint64_t Address, const void *Decoder);
313 static DecodeStatus DecodeT2ShifterImmOperand(llvm::MCInst &Inst, unsigned Val,
314                                 uint64_t Address, const void *Decoder);
315 
316 
317 
318 #include "ARMGenDisassemblerTables.inc"
319 #include "ARMGenInstrInfo.inc"
320 #include "ARMGenEDInfo.inc"
321 
322 static MCDisassembler *createARMDisassembler(const Target &T, const MCSubtargetInfo &STI) {
323   return new ARMDisassembler(STI);
324 }
325 
326 static MCDisassembler *createThumbDisassembler(const Target &T, const MCSubtargetInfo &STI) {
327   return new ThumbDisassembler(STI);
328 }
329 
330 EDInstInfo *ARMDisassembler::getEDInfo() const {
331   return instInfoARM;
332 }
333 
334 EDInstInfo *ThumbDisassembler::getEDInfo() const {
335   return instInfoARM;
336 }
337 
338 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
339                                              const MemoryObject &Region,
340                                              uint64_t Address,
341                                              raw_ostream &os,
342                                              raw_ostream &cs) const {
343   CommentStream = &cs;
344 
345   uint8_t bytes[4];
346 
347   assert(!(STI.getFeatureBits() & ARM::ModeThumb) &&
348          "Asked to disassemble an ARM instruction but Subtarget is in Thumb mode!");
349 
350   // We want to read exactly 4 bytes of data.
351   if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1) {
352     Size = 0;
353     return MCDisassembler::Fail;
354   }
355 
356   // Encoded as a small-endian 32-bit word in the stream.
357   uint32_t insn = (bytes[3] << 24) |
358                   (bytes[2] << 16) |
359                   (bytes[1] <<  8) |
360                   (bytes[0] <<  0);
361 
362   // Calling the auto-generated decoder function.
363   DecodeStatus result = decodeARMInstruction32(MI, insn, Address, this, STI);
364   if (result != MCDisassembler::Fail) {
365     Size = 4;
366     return result;
367   }
368 
369   // VFP and NEON instructions, similarly, are shared between ARM
370   // and Thumb modes.
371   MI.clear();
372   result = decodeVFPInstruction32(MI, insn, Address, this, STI);
373   if (result != MCDisassembler::Fail) {
374     Size = 4;
375     return result;
376   }
377 
378   MI.clear();
379   result = decodeNEONDataInstruction32(MI, insn, Address, this, STI);
380   if (result != MCDisassembler::Fail) {
381     Size = 4;
382     // Add a fake predicate operand, because we share these instruction
383     // definitions with Thumb2 where these instructions are predicable.
384     if (!DecodePredicateOperand(MI, 0xE, Address, this))
385       return MCDisassembler::Fail;
386     return result;
387   }
388 
389   MI.clear();
390   result = decodeNEONLoadStoreInstruction32(MI, insn, Address, this, STI);
391   if (result != MCDisassembler::Fail) {
392     Size = 4;
393     // Add a fake predicate operand, because we share these instruction
394     // definitions with Thumb2 where these instructions are predicable.
395     if (!DecodePredicateOperand(MI, 0xE, Address, this))
396       return MCDisassembler::Fail;
397     return result;
398   }
399 
400   MI.clear();
401   result = decodeNEONDupInstruction32(MI, insn, Address, this, STI);
402   if (result != MCDisassembler::Fail) {
403     Size = 4;
404     // Add a fake predicate operand, because we share these instruction
405     // definitions with Thumb2 where these instructions are predicable.
406     if (!DecodePredicateOperand(MI, 0xE, Address, this))
407       return MCDisassembler::Fail;
408     return result;
409   }
410 
411   MI.clear();
412 
413   Size = 0;
414   return MCDisassembler::Fail;
415 }
416 
417 namespace llvm {
418 extern MCInstrDesc ARMInsts[];
419 }
420 
421 /// tryAddingSymbolicOperand - trys to add a symbolic operand in place of the
422 /// immediate Value in the MCInst.  The immediate Value has had any PC
423 /// adjustment made by the caller.  If the instruction is a branch instruction
424 /// then isBranch is true, else false.  If the getOpInfo() function was set as
425 /// part of the setupForSymbolicDisassembly() call then that function is called
426 /// to get any symbolic information at the Address for this instruction.  If
427 /// that returns non-zero then the symbolic information it returns is used to
428 /// create an MCExpr and that is added as an operand to the MCInst.  If
429 /// getOpInfo() returns zero and isBranch is true then a symbol look up for
430 /// Value is done and if a symbol is found an MCExpr is created with that, else
431 /// an MCExpr with Value is created.  This function returns true if it adds an
432 /// operand to the MCInst and false otherwise.
433 static bool tryAddingSymbolicOperand(uint64_t Address, int32_t Value,
434                                      bool isBranch, uint64_t InstSize,
435                                      MCInst &MI, const void *Decoder) {
436   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
437   LLVMOpInfoCallback getOpInfo = Dis->getLLVMOpInfoCallback();
438   if (!getOpInfo)
439     return false;
440 
441   struct LLVMOpInfo1 SymbolicOp;
442   SymbolicOp.Value = Value;
443   void *DisInfo = Dis->getDisInfoBlock();
444   if (!getOpInfo(DisInfo, Address, 0 /* Offset */, InstSize, 1, &SymbolicOp)) {
445     if (isBranch) {
446       LLVMSymbolLookupCallback SymbolLookUp =
447                                             Dis->getLLVMSymbolLookupCallback();
448       if (SymbolLookUp) {
449         uint64_t ReferenceType;
450         ReferenceType = LLVMDisassembler_ReferenceType_In_Branch;
451         const char *ReferenceName;
452         const char *Name = SymbolLookUp(DisInfo, Value, &ReferenceType, Address,
453                                         &ReferenceName);
454         if (Name) {
455           SymbolicOp.AddSymbol.Name = Name;
456           SymbolicOp.AddSymbol.Present = true;
457           SymbolicOp.Value = 0;
458         }
459         else {
460           SymbolicOp.Value = Value;
461         }
462         if(ReferenceType == LLVMDisassembler_ReferenceType_Out_SymbolStub)
463           (*Dis->CommentStream) << "symbol stub for: " << ReferenceName;
464       }
465       else {
466         return false;
467       }
468     }
469     else {
470       return false;
471     }
472   }
473 
474   MCContext *Ctx = Dis->getMCContext();
475   const MCExpr *Add = NULL;
476   if (SymbolicOp.AddSymbol.Present) {
477     if (SymbolicOp.AddSymbol.Name) {
478       StringRef Name(SymbolicOp.AddSymbol.Name);
479       MCSymbol *Sym = Ctx->GetOrCreateSymbol(Name);
480       Add = MCSymbolRefExpr::Create(Sym, *Ctx);
481     } else {
482       Add = MCConstantExpr::Create(SymbolicOp.AddSymbol.Value, *Ctx);
483     }
484   }
485 
486   const MCExpr *Sub = NULL;
487   if (SymbolicOp.SubtractSymbol.Present) {
488     if (SymbolicOp.SubtractSymbol.Name) {
489       StringRef Name(SymbolicOp.SubtractSymbol.Name);
490       MCSymbol *Sym = Ctx->GetOrCreateSymbol(Name);
491       Sub = MCSymbolRefExpr::Create(Sym, *Ctx);
492     } else {
493       Sub = MCConstantExpr::Create(SymbolicOp.SubtractSymbol.Value, *Ctx);
494     }
495   }
496 
497   const MCExpr *Off = NULL;
498   if (SymbolicOp.Value != 0)
499     Off = MCConstantExpr::Create(SymbolicOp.Value, *Ctx);
500 
501   const MCExpr *Expr;
502   if (Sub) {
503     const MCExpr *LHS;
504     if (Add)
505       LHS = MCBinaryExpr::CreateSub(Add, Sub, *Ctx);
506     else
507       LHS = MCUnaryExpr::CreateMinus(Sub, *Ctx);
508     if (Off != 0)
509       Expr = MCBinaryExpr::CreateAdd(LHS, Off, *Ctx);
510     else
511       Expr = LHS;
512   } else if (Add) {
513     if (Off != 0)
514       Expr = MCBinaryExpr::CreateAdd(Add, Off, *Ctx);
515     else
516       Expr = Add;
517   } else {
518     if (Off != 0)
519       Expr = Off;
520     else
521       Expr = MCConstantExpr::Create(0, *Ctx);
522   }
523 
524   if (SymbolicOp.VariantKind == LLVMDisassembler_VariantKind_ARM_HI16)
525     MI.addOperand(MCOperand::CreateExpr(ARMMCExpr::CreateUpper16(Expr, *Ctx)));
526   else if (SymbolicOp.VariantKind == LLVMDisassembler_VariantKind_ARM_LO16)
527     MI.addOperand(MCOperand::CreateExpr(ARMMCExpr::CreateLower16(Expr, *Ctx)));
528   else if (SymbolicOp.VariantKind == LLVMDisassembler_VariantKind_None)
529     MI.addOperand(MCOperand::CreateExpr(Expr));
530   else
531     assert("bad SymbolicOp.VariantKind");
532 
533   return true;
534 }
535 
536 /// tryAddingPcLoadReferenceComment - trys to add a comment as to what is being
537 /// referenced by a load instruction with the base register that is the Pc.
538 /// These can often be values in a literal pool near the Address of the
539 /// instruction.  The Address of the instruction and its immediate Value are
540 /// used as a possible literal pool entry.  The SymbolLookUp call back will
541 /// return the name of a symbol referenced by the the literal pool's entry if
542 /// the referenced address is that of a symbol.  Or it will return a pointer to
543 /// a literal 'C' string if the referenced address of the literal pool's entry
544 /// is an address into a section with 'C' string literals.
545 static void tryAddingPcLoadReferenceComment(uint64_t Address, int Value,
546 					    const void *Decoder) {
547   const MCDisassembler *Dis = static_cast<const MCDisassembler*>(Decoder);
548   LLVMSymbolLookupCallback SymbolLookUp = Dis->getLLVMSymbolLookupCallback();
549   if (SymbolLookUp) {
550     void *DisInfo = Dis->getDisInfoBlock();
551     uint64_t ReferenceType;
552     ReferenceType = LLVMDisassembler_ReferenceType_In_PCrel_Load;
553     const char *ReferenceName;
554     (void)SymbolLookUp(DisInfo, Value, &ReferenceType, Address, &ReferenceName);
555     if(ReferenceType == LLVMDisassembler_ReferenceType_Out_LitPool_SymAddr ||
556        ReferenceType == LLVMDisassembler_ReferenceType_Out_LitPool_CstrAddr)
557       (*Dis->CommentStream) << "literal pool for: " << ReferenceName;
558   }
559 }
560 
561 // Thumb1 instructions don't have explicit S bits.  Rather, they
562 // implicitly set CPSR.  Since it's not represented in the encoding, the
563 // auto-generated decoder won't inject the CPSR operand.  We need to fix
564 // that as a post-pass.
565 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
566   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
567   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
568   MCInst::iterator I = MI.begin();
569   for (unsigned i = 0; i < NumOps; ++i, ++I) {
570     if (I == MI.end()) break;
571     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
572       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
573       MI.insert(I, MCOperand::CreateReg(InITBlock ? 0 : ARM::CPSR));
574       return;
575     }
576   }
577 
578   MI.insert(I, MCOperand::CreateReg(InITBlock ? 0 : ARM::CPSR));
579 }
580 
581 // Most Thumb instructions don't have explicit predicates in the
582 // encoding, but rather get their predicates from IT context.  We need
583 // to fix up the predicate operands using this context information as a
584 // post-pass.
585 MCDisassembler::DecodeStatus
586 ThumbDisassembler::AddThumbPredicate(MCInst &MI) const {
587   MCDisassembler::DecodeStatus S = Success;
588 
589   // A few instructions actually have predicates encoded in them.  Don't
590   // try to overwrite it if we're seeing one of those.
591   switch (MI.getOpcode()) {
592     case ARM::tBcc:
593     case ARM::t2Bcc:
594     case ARM::tCBZ:
595     case ARM::tCBNZ:
596     case ARM::tCPS:
597     case ARM::t2CPS3p:
598     case ARM::t2CPS2p:
599     case ARM::t2CPS1p:
600     case ARM::tMOVSr:
601       // Some instructions (mostly conditional branches) are not
602       // allowed in IT blocks.
603       if (!ITBlock.empty())
604         S = SoftFail;
605       else
606         return Success;
607       break;
608     case ARM::tB:
609     case ARM::t2B:
610     case ARM::t2TBB:
611     case ARM::t2TBH:
612       // Some instructions (mostly unconditional branches) can
613       // only appears at the end of, or outside of, an IT.
614       if (ITBlock.size() > 1)
615         S = SoftFail;
616       break;
617     default:
618       break;
619   }
620 
621   // If we're in an IT block, base the predicate on that.  Otherwise,
622   // assume a predicate of AL.
623   unsigned CC;
624   if (!ITBlock.empty()) {
625     CC = ITBlock.back();
626     if (CC == 0xF)
627       CC = ARMCC::AL;
628     ITBlock.pop_back();
629   } else
630     CC = ARMCC::AL;
631 
632   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
633   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
634   MCInst::iterator I = MI.begin();
635   for (unsigned i = 0; i < NumOps; ++i, ++I) {
636     if (I == MI.end()) break;
637     if (OpInfo[i].isPredicate()) {
638       I = MI.insert(I, MCOperand::CreateImm(CC));
639       ++I;
640       if (CC == ARMCC::AL)
641         MI.insert(I, MCOperand::CreateReg(0));
642       else
643         MI.insert(I, MCOperand::CreateReg(ARM::CPSR));
644       return S;
645     }
646   }
647 
648   I = MI.insert(I, MCOperand::CreateImm(CC));
649   ++I;
650   if (CC == ARMCC::AL)
651     MI.insert(I, MCOperand::CreateReg(0));
652   else
653     MI.insert(I, MCOperand::CreateReg(ARM::CPSR));
654 
655   return S;
656 }
657 
658 // Thumb VFP instructions are a special case.  Because we share their
659 // encodings between ARM and Thumb modes, and they are predicable in ARM
660 // mode, the auto-generated decoder will give them an (incorrect)
661 // predicate operand.  We need to rewrite these operands based on the IT
662 // context as a post-pass.
663 void ThumbDisassembler::UpdateThumbVFPPredicate(MCInst &MI) const {
664   unsigned CC;
665   if (!ITBlock.empty()) {
666     CC = ITBlock.back();
667     ITBlock.pop_back();
668   } else
669     CC = ARMCC::AL;
670 
671   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
672   MCInst::iterator I = MI.begin();
673   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
674   for (unsigned i = 0; i < NumOps; ++i, ++I) {
675     if (OpInfo[i].isPredicate() ) {
676       I->setImm(CC);
677       ++I;
678       if (CC == ARMCC::AL)
679         I->setReg(0);
680       else
681         I->setReg(ARM::CPSR);
682       return;
683     }
684   }
685 }
686 
687 DecodeStatus ThumbDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
688                                                const MemoryObject &Region,
689                                                uint64_t Address,
690                                                raw_ostream &os,
691                                                raw_ostream &cs) const {
692   CommentStream = &cs;
693 
694   uint8_t bytes[4];
695 
696   assert((STI.getFeatureBits() & ARM::ModeThumb) &&
697          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
698 
699   // We want to read exactly 2 bytes of data.
700   if (Region.readBytes(Address, 2, (uint8_t*)bytes, NULL) == -1) {
701     Size = 0;
702     return MCDisassembler::Fail;
703   }
704 
705   uint16_t insn16 = (bytes[1] << 8) | bytes[0];
706   DecodeStatus result = decodeThumbInstruction16(MI, insn16, Address, this, STI);
707   if (result != MCDisassembler::Fail) {
708     Size = 2;
709     Check(result, AddThumbPredicate(MI));
710     return result;
711   }
712 
713   MI.clear();
714   result = decodeThumbSBitInstruction16(MI, insn16, Address, this, STI);
715   if (result) {
716     Size = 2;
717     bool InITBlock = !ITBlock.empty();
718     Check(result, AddThumbPredicate(MI));
719     AddThumb1SBit(MI, InITBlock);
720     return result;
721   }
722 
723   MI.clear();
724   result = decodeThumb2Instruction16(MI, insn16, Address, this, STI);
725   if (result != MCDisassembler::Fail) {
726     Size = 2;
727 
728     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
729     // the Thumb predicate.
730     if (MI.getOpcode() == ARM::t2IT && !ITBlock.empty())
731       result = MCDisassembler::SoftFail;
732 
733     Check(result, AddThumbPredicate(MI));
734 
735     // If we find an IT instruction, we need to parse its condition
736     // code and mask operands so that we can apply them correctly
737     // to the subsequent instructions.
738     if (MI.getOpcode() == ARM::t2IT) {
739 
740       // (3 - the number of trailing zeros) is the number of then / else.
741       unsigned firstcond = MI.getOperand(0).getImm();
742       unsigned Mask = MI.getOperand(1).getImm();
743       unsigned CondBit0 = Mask >> 4 & 1;
744       unsigned NumTZ = CountTrailingZeros_32(Mask);
745       assert(NumTZ <= 3 && "Invalid IT mask!");
746       for (unsigned Pos = 3, e = NumTZ; Pos > e; --Pos) {
747         bool T = ((Mask >> Pos) & 1) == CondBit0;
748         if (T)
749           ITBlock.insert(ITBlock.begin(), firstcond);
750         else
751           ITBlock.insert(ITBlock.begin(), firstcond ^ 1);
752       }
753 
754       ITBlock.push_back(firstcond);
755     }
756 
757     return result;
758   }
759 
760   // We want to read exactly 4 bytes of data.
761   if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1) {
762     Size = 0;
763     return MCDisassembler::Fail;
764   }
765 
766   uint32_t insn32 = (bytes[3] <<  8) |
767                     (bytes[2] <<  0) |
768                     (bytes[1] << 24) |
769                     (bytes[0] << 16);
770   MI.clear();
771   result = decodeThumbInstruction32(MI, insn32, Address, this, STI);
772   if (result != MCDisassembler::Fail) {
773     Size = 4;
774     bool InITBlock = ITBlock.size();
775     Check(result, AddThumbPredicate(MI));
776     AddThumb1SBit(MI, InITBlock);
777     return result;
778   }
779 
780   MI.clear();
781   result = decodeThumb2Instruction32(MI, insn32, Address, this, STI);
782   if (result != MCDisassembler::Fail) {
783     Size = 4;
784     Check(result, AddThumbPredicate(MI));
785     return result;
786   }
787 
788   MI.clear();
789   result = decodeVFPInstruction32(MI, insn32, Address, this, STI);
790   if (result != MCDisassembler::Fail) {
791     Size = 4;
792     UpdateThumbVFPPredicate(MI);
793     return result;
794   }
795 
796   MI.clear();
797   result = decodeNEONDupInstruction32(MI, insn32, Address, this, STI);
798   if (result != MCDisassembler::Fail) {
799     Size = 4;
800     Check(result, AddThumbPredicate(MI));
801     return result;
802   }
803 
804   if (fieldFromInstruction32(insn32, 24, 8) == 0xF9) {
805     MI.clear();
806     uint32_t NEONLdStInsn = insn32;
807     NEONLdStInsn &= 0xF0FFFFFF;
808     NEONLdStInsn |= 0x04000000;
809     result = decodeNEONLoadStoreInstruction32(MI, NEONLdStInsn, Address, this, STI);
810     if (result != MCDisassembler::Fail) {
811       Size = 4;
812       Check(result, AddThumbPredicate(MI));
813       return result;
814     }
815   }
816 
817   if (fieldFromInstruction32(insn32, 24, 4) == 0xF) {
818     MI.clear();
819     uint32_t NEONDataInsn = insn32;
820     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
821     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
822     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
823     result = decodeNEONDataInstruction32(MI, NEONDataInsn, Address, this, STI);
824     if (result != MCDisassembler::Fail) {
825       Size = 4;
826       Check(result, AddThumbPredicate(MI));
827       return result;
828     }
829   }
830 
831   Size = 0;
832   return MCDisassembler::Fail;
833 }
834 
835 
836 extern "C" void LLVMInitializeARMDisassembler() {
837   TargetRegistry::RegisterMCDisassembler(TheARMTarget,
838                                          createARMDisassembler);
839   TargetRegistry::RegisterMCDisassembler(TheThumbTarget,
840                                          createThumbDisassembler);
841 }
842 
843 static const unsigned GPRDecoderTable[] = {
844   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
845   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
846   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
847   ARM::R12, ARM::SP, ARM::LR, ARM::PC
848 };
849 
850 static DecodeStatus DecodeGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
851                                    uint64_t Address, const void *Decoder) {
852   if (RegNo > 15)
853     return MCDisassembler::Fail;
854 
855   unsigned Register = GPRDecoderTable[RegNo];
856   Inst.addOperand(MCOperand::CreateReg(Register));
857   return MCDisassembler::Success;
858 }
859 
860 static DecodeStatus
861 DecodeGPRnopcRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
862                            uint64_t Address, const void *Decoder) {
863   if (RegNo == 15) return MCDisassembler::Fail;
864   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
865 }
866 
867 static DecodeStatus DecodetGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
868                                    uint64_t Address, const void *Decoder) {
869   if (RegNo > 7)
870     return MCDisassembler::Fail;
871   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
872 }
873 
874 static DecodeStatus DecodetcGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
875                                    uint64_t Address, const void *Decoder) {
876   unsigned Register = 0;
877   switch (RegNo) {
878     case 0:
879       Register = ARM::R0;
880       break;
881     case 1:
882       Register = ARM::R1;
883       break;
884     case 2:
885       Register = ARM::R2;
886       break;
887     case 3:
888       Register = ARM::R3;
889       break;
890     case 9:
891       Register = ARM::R9;
892       break;
893     case 12:
894       Register = ARM::R12;
895       break;
896     default:
897       return MCDisassembler::Fail;
898     }
899 
900   Inst.addOperand(MCOperand::CreateReg(Register));
901   return MCDisassembler::Success;
902 }
903 
904 static DecodeStatus DecoderGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
905                                    uint64_t Address, const void *Decoder) {
906   if (RegNo == 13 || RegNo == 15) return MCDisassembler::Fail;
907   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
908 }
909 
910 static const unsigned SPRDecoderTable[] = {
911      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
912      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
913      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
914     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
915     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
916     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
917     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
918     ARM::S28, ARM::S29, ARM::S30, ARM::S31
919 };
920 
921 static DecodeStatus DecodeSPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
922                                    uint64_t Address, const void *Decoder) {
923   if (RegNo > 31)
924     return MCDisassembler::Fail;
925 
926   unsigned Register = SPRDecoderTable[RegNo];
927   Inst.addOperand(MCOperand::CreateReg(Register));
928   return MCDisassembler::Success;
929 }
930 
931 static const unsigned DPRDecoderTable[] = {
932      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
933      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
934      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
935     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
936     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
937     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
938     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
939     ARM::D28, ARM::D29, ARM::D30, ARM::D31
940 };
941 
942 static DecodeStatus DecodeDPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
943                                    uint64_t Address, const void *Decoder) {
944   if (RegNo > 31)
945     return MCDisassembler::Fail;
946 
947   unsigned Register = DPRDecoderTable[RegNo];
948   Inst.addOperand(MCOperand::CreateReg(Register));
949   return MCDisassembler::Success;
950 }
951 
952 static DecodeStatus DecodeDPR_8RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
953                                    uint64_t Address, const void *Decoder) {
954   if (RegNo > 7)
955     return MCDisassembler::Fail;
956   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
957 }
958 
959 static DecodeStatus
960 DecodeDPR_VFP2RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
961                             uint64_t Address, const void *Decoder) {
962   if (RegNo > 15)
963     return MCDisassembler::Fail;
964   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
965 }
966 
967 static const unsigned QPRDecoderTable[] = {
968      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
969      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
970      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
971     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
972 };
973 
974 
975 static DecodeStatus DecodeQPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
976                                    uint64_t Address, const void *Decoder) {
977   if (RegNo > 31)
978     return MCDisassembler::Fail;
979   RegNo >>= 1;
980 
981   unsigned Register = QPRDecoderTable[RegNo];
982   Inst.addOperand(MCOperand::CreateReg(Register));
983   return MCDisassembler::Success;
984 }
985 
986 static DecodeStatus DecodePredicateOperand(llvm::MCInst &Inst, unsigned Val,
987                                uint64_t Address, const void *Decoder) {
988   if (Val == 0xF) return MCDisassembler::Fail;
989   // AL predicate is not allowed on Thumb1 branches.
990   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
991     return MCDisassembler::Fail;
992   Inst.addOperand(MCOperand::CreateImm(Val));
993   if (Val == ARMCC::AL) {
994     Inst.addOperand(MCOperand::CreateReg(0));
995   } else
996     Inst.addOperand(MCOperand::CreateReg(ARM::CPSR));
997   return MCDisassembler::Success;
998 }
999 
1000 static DecodeStatus DecodeCCOutOperand(llvm::MCInst &Inst, unsigned Val,
1001                                uint64_t Address, const void *Decoder) {
1002   if (Val)
1003     Inst.addOperand(MCOperand::CreateReg(ARM::CPSR));
1004   else
1005     Inst.addOperand(MCOperand::CreateReg(0));
1006   return MCDisassembler::Success;
1007 }
1008 
1009 static DecodeStatus DecodeSOImmOperand(llvm::MCInst &Inst, unsigned Val,
1010                                uint64_t Address, const void *Decoder) {
1011   uint32_t imm = Val & 0xFF;
1012   uint32_t rot = (Val & 0xF00) >> 7;
1013   uint32_t rot_imm = (imm >> rot) | (imm << (32-rot));
1014   Inst.addOperand(MCOperand::CreateImm(rot_imm));
1015   return MCDisassembler::Success;
1016 }
1017 
1018 static DecodeStatus DecodeSORegImmOperand(llvm::MCInst &Inst, unsigned Val,
1019                                uint64_t Address, const void *Decoder) {
1020   DecodeStatus S = MCDisassembler::Success;
1021 
1022   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
1023   unsigned type = fieldFromInstruction32(Val, 5, 2);
1024   unsigned imm = fieldFromInstruction32(Val, 7, 5);
1025 
1026   // Register-immediate
1027   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1028     return MCDisassembler::Fail;
1029 
1030   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1031   switch (type) {
1032     case 0:
1033       Shift = ARM_AM::lsl;
1034       break;
1035     case 1:
1036       Shift = ARM_AM::lsr;
1037       break;
1038     case 2:
1039       Shift = ARM_AM::asr;
1040       break;
1041     case 3:
1042       Shift = ARM_AM::ror;
1043       break;
1044   }
1045 
1046   if (Shift == ARM_AM::ror && imm == 0)
1047     Shift = ARM_AM::rrx;
1048 
1049   unsigned Op = Shift | (imm << 3);
1050   Inst.addOperand(MCOperand::CreateImm(Op));
1051 
1052   return S;
1053 }
1054 
1055 static DecodeStatus DecodeSORegRegOperand(llvm::MCInst &Inst, unsigned Val,
1056                                uint64_t Address, const void *Decoder) {
1057   DecodeStatus S = MCDisassembler::Success;
1058 
1059   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
1060   unsigned type = fieldFromInstruction32(Val, 5, 2);
1061   unsigned Rs = fieldFromInstruction32(Val, 8, 4);
1062 
1063   // Register-register
1064   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1065     return MCDisassembler::Fail;
1066   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1067     return MCDisassembler::Fail;
1068 
1069   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1070   switch (type) {
1071     case 0:
1072       Shift = ARM_AM::lsl;
1073       break;
1074     case 1:
1075       Shift = ARM_AM::lsr;
1076       break;
1077     case 2:
1078       Shift = ARM_AM::asr;
1079       break;
1080     case 3:
1081       Shift = ARM_AM::ror;
1082       break;
1083   }
1084 
1085   Inst.addOperand(MCOperand::CreateImm(Shift));
1086 
1087   return S;
1088 }
1089 
1090 static DecodeStatus DecodeRegListOperand(llvm::MCInst &Inst, unsigned Val,
1091                                  uint64_t Address, const void *Decoder) {
1092   DecodeStatus S = MCDisassembler::Success;
1093 
1094   bool writebackLoad = false;
1095   unsigned writebackReg = 0;
1096   switch (Inst.getOpcode()) {
1097     default:
1098       break;
1099     case ARM::LDMIA_UPD:
1100     case ARM::LDMDB_UPD:
1101     case ARM::LDMIB_UPD:
1102     case ARM::LDMDA_UPD:
1103     case ARM::t2LDMIA_UPD:
1104     case ARM::t2LDMDB_UPD:
1105       writebackLoad = true;
1106       writebackReg = Inst.getOperand(0).getReg();
1107       break;
1108   }
1109 
1110   // Empty register lists are not allowed.
1111   if (CountPopulation_32(Val) == 0) return MCDisassembler::Fail;
1112   for (unsigned i = 0; i < 16; ++i) {
1113     if (Val & (1 << i)) {
1114       if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1115         return MCDisassembler::Fail;
1116       // Writeback not allowed if Rn is in the target list.
1117       if (writebackLoad && writebackReg == Inst.end()[-1].getReg())
1118         Check(S, MCDisassembler::SoftFail);
1119     }
1120   }
1121 
1122   return S;
1123 }
1124 
1125 static DecodeStatus DecodeSPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
1126                                  uint64_t Address, const void *Decoder) {
1127   DecodeStatus S = MCDisassembler::Success;
1128 
1129   unsigned Vd = fieldFromInstruction32(Val, 8, 4);
1130   unsigned regs = Val & 0xFF;
1131 
1132   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1133     return MCDisassembler::Fail;
1134   for (unsigned i = 0; i < (regs - 1); ++i) {
1135     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1136       return MCDisassembler::Fail;
1137   }
1138 
1139   return S;
1140 }
1141 
1142 static DecodeStatus DecodeDPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
1143                                  uint64_t Address, const void *Decoder) {
1144   DecodeStatus S = MCDisassembler::Success;
1145 
1146   unsigned Vd = fieldFromInstruction32(Val, 8, 4);
1147   unsigned regs = (Val & 0xFF) / 2;
1148 
1149   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1150       return MCDisassembler::Fail;
1151   for (unsigned i = 0; i < (regs - 1); ++i) {
1152     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1153       return MCDisassembler::Fail;
1154   }
1155 
1156   return S;
1157 }
1158 
1159 static DecodeStatus DecodeBitfieldMaskOperand(llvm::MCInst &Inst, unsigned Val,
1160                                       uint64_t Address, const void *Decoder) {
1161   // This operand encodes a mask of contiguous zeros between a specified MSB
1162   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1163   // the mask of all bits LSB-and-lower, and then xor them to create
1164   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1165   // create the final mask.
1166   unsigned msb = fieldFromInstruction32(Val, 5, 5);
1167   unsigned lsb = fieldFromInstruction32(Val, 0, 5);
1168 
1169   DecodeStatus S = MCDisassembler::Success;
1170   if (lsb > msb) Check(S, MCDisassembler::SoftFail);
1171 
1172   uint32_t msb_mask = 0xFFFFFFFF;
1173   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1174   uint32_t lsb_mask = (1U << lsb) - 1;
1175 
1176   Inst.addOperand(MCOperand::CreateImm(~(msb_mask ^ lsb_mask)));
1177   return S;
1178 }
1179 
1180 static DecodeStatus DecodeCopMemInstruction(llvm::MCInst &Inst, unsigned Insn,
1181                                   uint64_t Address, const void *Decoder) {
1182   DecodeStatus S = MCDisassembler::Success;
1183 
1184   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1185   unsigned CRd = fieldFromInstruction32(Insn, 12, 4);
1186   unsigned coproc = fieldFromInstruction32(Insn, 8, 4);
1187   unsigned imm = fieldFromInstruction32(Insn, 0, 8);
1188   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1189   unsigned U = fieldFromInstruction32(Insn, 23, 1);
1190 
1191   switch (Inst.getOpcode()) {
1192     case ARM::LDC_OFFSET:
1193     case ARM::LDC_PRE:
1194     case ARM::LDC_POST:
1195     case ARM::LDC_OPTION:
1196     case ARM::LDCL_OFFSET:
1197     case ARM::LDCL_PRE:
1198     case ARM::LDCL_POST:
1199     case ARM::LDCL_OPTION:
1200     case ARM::STC_OFFSET:
1201     case ARM::STC_PRE:
1202     case ARM::STC_POST:
1203     case ARM::STC_OPTION:
1204     case ARM::STCL_OFFSET:
1205     case ARM::STCL_PRE:
1206     case ARM::STCL_POST:
1207     case ARM::STCL_OPTION:
1208     case ARM::t2LDC_OFFSET:
1209     case ARM::t2LDC_PRE:
1210     case ARM::t2LDC_POST:
1211     case ARM::t2LDC_OPTION:
1212     case ARM::t2LDCL_OFFSET:
1213     case ARM::t2LDCL_PRE:
1214     case ARM::t2LDCL_POST:
1215     case ARM::t2LDCL_OPTION:
1216     case ARM::t2STC_OFFSET:
1217     case ARM::t2STC_PRE:
1218     case ARM::t2STC_POST:
1219     case ARM::t2STC_OPTION:
1220     case ARM::t2STCL_OFFSET:
1221     case ARM::t2STCL_PRE:
1222     case ARM::t2STCL_POST:
1223     case ARM::t2STCL_OPTION:
1224       if (coproc == 0xA || coproc == 0xB)
1225         return MCDisassembler::Fail;
1226       break;
1227     default:
1228       break;
1229   }
1230 
1231   Inst.addOperand(MCOperand::CreateImm(coproc));
1232   Inst.addOperand(MCOperand::CreateImm(CRd));
1233   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1234     return MCDisassembler::Fail;
1235   switch (Inst.getOpcode()) {
1236     case ARM::LDC_OPTION:
1237     case ARM::LDCL_OPTION:
1238     case ARM::LDC2_OPTION:
1239     case ARM::LDC2L_OPTION:
1240     case ARM::STC_OPTION:
1241     case ARM::STCL_OPTION:
1242     case ARM::STC2_OPTION:
1243     case ARM::STC2L_OPTION:
1244     case ARM::LDCL_POST:
1245     case ARM::STCL_POST:
1246     case ARM::LDC2L_POST:
1247     case ARM::STC2L_POST:
1248     case ARM::t2LDC_OPTION:
1249     case ARM::t2LDCL_OPTION:
1250     case ARM::t2STC_OPTION:
1251     case ARM::t2STCL_OPTION:
1252     case ARM::t2LDCL_POST:
1253     case ARM::t2STCL_POST:
1254       break;
1255     default:
1256       Inst.addOperand(MCOperand::CreateReg(0));
1257       break;
1258   }
1259 
1260   unsigned P = fieldFromInstruction32(Insn, 24, 1);
1261   unsigned W = fieldFromInstruction32(Insn, 21, 1);
1262 
1263   bool writeback = (P == 0) || (W == 1);
1264   unsigned idx_mode = 0;
1265   if (P && writeback)
1266     idx_mode = ARMII::IndexModePre;
1267   else if (!P && writeback)
1268     idx_mode = ARMII::IndexModePost;
1269 
1270   switch (Inst.getOpcode()) {
1271     case ARM::LDCL_POST:
1272     case ARM::STCL_POST:
1273     case ARM::t2LDCL_POST:
1274     case ARM::t2STCL_POST:
1275     case ARM::LDC2L_POST:
1276     case ARM::STC2L_POST:
1277       imm |= U << 8;
1278     case ARM::LDC_OPTION:
1279     case ARM::LDCL_OPTION:
1280     case ARM::LDC2_OPTION:
1281     case ARM::LDC2L_OPTION:
1282     case ARM::STC_OPTION:
1283     case ARM::STCL_OPTION:
1284     case ARM::STC2_OPTION:
1285     case ARM::STC2L_OPTION:
1286     case ARM::t2LDC_OPTION:
1287     case ARM::t2LDCL_OPTION:
1288     case ARM::t2STC_OPTION:
1289     case ARM::t2STCL_OPTION:
1290       Inst.addOperand(MCOperand::CreateImm(imm));
1291       break;
1292     default:
1293       if (U)
1294         Inst.addOperand(MCOperand::CreateImm(
1295             ARM_AM::getAM2Opc(ARM_AM::add, imm, ARM_AM::lsl, idx_mode)));
1296       else
1297         Inst.addOperand(MCOperand::CreateImm(
1298             ARM_AM::getAM2Opc(ARM_AM::sub, imm, ARM_AM::lsl, idx_mode)));
1299       break;
1300   }
1301 
1302   switch (Inst.getOpcode()) {
1303     case ARM::LDC_OFFSET:
1304     case ARM::LDC_PRE:
1305     case ARM::LDC_POST:
1306     case ARM::LDC_OPTION:
1307     case ARM::LDCL_OFFSET:
1308     case ARM::LDCL_PRE:
1309     case ARM::LDCL_POST:
1310     case ARM::LDCL_OPTION:
1311     case ARM::STC_OFFSET:
1312     case ARM::STC_PRE:
1313     case ARM::STC_POST:
1314     case ARM::STC_OPTION:
1315     case ARM::STCL_OFFSET:
1316     case ARM::STCL_PRE:
1317     case ARM::STCL_POST:
1318     case ARM::STCL_OPTION:
1319       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1320         return MCDisassembler::Fail;
1321       break;
1322     default:
1323       break;
1324   }
1325 
1326   return S;
1327 }
1328 
1329 static DecodeStatus
1330 DecodeAddrMode2IdxInstruction(llvm::MCInst &Inst, unsigned Insn,
1331                               uint64_t Address, const void *Decoder) {
1332   DecodeStatus S = MCDisassembler::Success;
1333 
1334   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1335   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
1336   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1337   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
1338   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1339   unsigned reg = fieldFromInstruction32(Insn, 25, 1);
1340   unsigned P = fieldFromInstruction32(Insn, 24, 1);
1341   unsigned W = fieldFromInstruction32(Insn, 21, 1);
1342 
1343   // On stores, the writeback operand precedes Rt.
1344   switch (Inst.getOpcode()) {
1345     case ARM::STR_POST_IMM:
1346     case ARM::STR_POST_REG:
1347     case ARM::STRB_POST_IMM:
1348     case ARM::STRB_POST_REG:
1349     case ARM::STRT_POST_REG:
1350     case ARM::STRT_POST_IMM:
1351     case ARM::STRBT_POST_REG:
1352     case ARM::STRBT_POST_IMM:
1353       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1354         return MCDisassembler::Fail;
1355       break;
1356     default:
1357       break;
1358   }
1359 
1360   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1361     return MCDisassembler::Fail;
1362 
1363   // On loads, the writeback operand comes after Rt.
1364   switch (Inst.getOpcode()) {
1365     case ARM::LDR_POST_IMM:
1366     case ARM::LDR_POST_REG:
1367     case ARM::LDRB_POST_IMM:
1368     case ARM::LDRB_POST_REG:
1369     case ARM::LDRBT_POST_REG:
1370     case ARM::LDRBT_POST_IMM:
1371     case ARM::LDRT_POST_REG:
1372     case ARM::LDRT_POST_IMM:
1373       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1374         return MCDisassembler::Fail;
1375       break;
1376     default:
1377       break;
1378   }
1379 
1380   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1381     return MCDisassembler::Fail;
1382 
1383   ARM_AM::AddrOpc Op = ARM_AM::add;
1384   if (!fieldFromInstruction32(Insn, 23, 1))
1385     Op = ARM_AM::sub;
1386 
1387   bool writeback = (P == 0) || (W == 1);
1388   unsigned idx_mode = 0;
1389   if (P && writeback)
1390     idx_mode = ARMII::IndexModePre;
1391   else if (!P && writeback)
1392     idx_mode = ARMII::IndexModePost;
1393 
1394   if (writeback && (Rn == 15 || Rn == Rt))
1395     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1396 
1397   if (reg) {
1398     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1399       return MCDisassembler::Fail;
1400     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1401     switch( fieldFromInstruction32(Insn, 5, 2)) {
1402       case 0:
1403         Opc = ARM_AM::lsl;
1404         break;
1405       case 1:
1406         Opc = ARM_AM::lsr;
1407         break;
1408       case 2:
1409         Opc = ARM_AM::asr;
1410         break;
1411       case 3:
1412         Opc = ARM_AM::ror;
1413         break;
1414       default:
1415         return MCDisassembler::Fail;
1416     }
1417     unsigned amt = fieldFromInstruction32(Insn, 7, 5);
1418     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1419 
1420     Inst.addOperand(MCOperand::CreateImm(imm));
1421   } else {
1422     Inst.addOperand(MCOperand::CreateReg(0));
1423     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1424     Inst.addOperand(MCOperand::CreateImm(tmp));
1425   }
1426 
1427   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1428     return MCDisassembler::Fail;
1429 
1430   return S;
1431 }
1432 
1433 static DecodeStatus DecodeSORegMemOperand(llvm::MCInst &Inst, unsigned Val,
1434                                   uint64_t Address, const void *Decoder) {
1435   DecodeStatus S = MCDisassembler::Success;
1436 
1437   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
1438   unsigned Rm = fieldFromInstruction32(Val,  0, 4);
1439   unsigned type = fieldFromInstruction32(Val, 5, 2);
1440   unsigned imm = fieldFromInstruction32(Val, 7, 5);
1441   unsigned U = fieldFromInstruction32(Val, 12, 1);
1442 
1443   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1444   switch (type) {
1445     case 0:
1446       ShOp = ARM_AM::lsl;
1447       break;
1448     case 1:
1449       ShOp = ARM_AM::lsr;
1450       break;
1451     case 2:
1452       ShOp = ARM_AM::asr;
1453       break;
1454     case 3:
1455       ShOp = ARM_AM::ror;
1456       break;
1457   }
1458 
1459   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1460     return MCDisassembler::Fail;
1461   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1462     return MCDisassembler::Fail;
1463   unsigned shift;
1464   if (U)
1465     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1466   else
1467     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1468   Inst.addOperand(MCOperand::CreateImm(shift));
1469 
1470   return S;
1471 }
1472 
1473 static DecodeStatus
1474 DecodeAddrMode3Instruction(llvm::MCInst &Inst, unsigned Insn,
1475                            uint64_t Address, const void *Decoder) {
1476   DecodeStatus S = MCDisassembler::Success;
1477 
1478   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
1479   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1480   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1481   unsigned type = fieldFromInstruction32(Insn, 22, 1);
1482   unsigned imm = fieldFromInstruction32(Insn, 8, 4);
1483   unsigned U = ((~fieldFromInstruction32(Insn, 23, 1)) & 1) << 8;
1484   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1485   unsigned W = fieldFromInstruction32(Insn, 21, 1);
1486   unsigned P = fieldFromInstruction32(Insn, 24, 1);
1487 
1488   bool writeback = (W == 1) | (P == 0);
1489 
1490   // For {LD,ST}RD, Rt must be even, else undefined.
1491   switch (Inst.getOpcode()) {
1492     case ARM::STRD:
1493     case ARM::STRD_PRE:
1494     case ARM::STRD_POST:
1495     case ARM::LDRD:
1496     case ARM::LDRD_PRE:
1497     case ARM::LDRD_POST:
1498       if (Rt & 0x1) return MCDisassembler::Fail;
1499       break;
1500     default:
1501       break;
1502   }
1503 
1504   if (writeback) { // Writeback
1505     if (P)
1506       U |= ARMII::IndexModePre << 9;
1507     else
1508       U |= ARMII::IndexModePost << 9;
1509 
1510     // On stores, the writeback operand precedes Rt.
1511     switch (Inst.getOpcode()) {
1512     case ARM::STRD:
1513     case ARM::STRD_PRE:
1514     case ARM::STRD_POST:
1515     case ARM::STRH:
1516     case ARM::STRH_PRE:
1517     case ARM::STRH_POST:
1518       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1519         return MCDisassembler::Fail;
1520       break;
1521     default:
1522       break;
1523     }
1524   }
1525 
1526   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1527     return MCDisassembler::Fail;
1528   switch (Inst.getOpcode()) {
1529     case ARM::STRD:
1530     case ARM::STRD_PRE:
1531     case ARM::STRD_POST:
1532     case ARM::LDRD:
1533     case ARM::LDRD_PRE:
1534     case ARM::LDRD_POST:
1535       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
1536         return MCDisassembler::Fail;
1537       break;
1538     default:
1539       break;
1540   }
1541 
1542   if (writeback) {
1543     // On loads, the writeback operand comes after Rt.
1544     switch (Inst.getOpcode()) {
1545     case ARM::LDRD:
1546     case ARM::LDRD_PRE:
1547     case ARM::LDRD_POST:
1548     case ARM::LDRH:
1549     case ARM::LDRH_PRE:
1550     case ARM::LDRH_POST:
1551     case ARM::LDRSH:
1552     case ARM::LDRSH_PRE:
1553     case ARM::LDRSH_POST:
1554     case ARM::LDRSB:
1555     case ARM::LDRSB_PRE:
1556     case ARM::LDRSB_POST:
1557     case ARM::LDRHTr:
1558     case ARM::LDRSBTr:
1559       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1560         return MCDisassembler::Fail;
1561       break;
1562     default:
1563       break;
1564     }
1565   }
1566 
1567   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1568     return MCDisassembler::Fail;
1569 
1570   if (type) {
1571     Inst.addOperand(MCOperand::CreateReg(0));
1572     Inst.addOperand(MCOperand::CreateImm(U | (imm << 4) | Rm));
1573   } else {
1574     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1575     return MCDisassembler::Fail;
1576     Inst.addOperand(MCOperand::CreateImm(U));
1577   }
1578 
1579   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1580     return MCDisassembler::Fail;
1581 
1582   return S;
1583 }
1584 
1585 static DecodeStatus DecodeRFEInstruction(llvm::MCInst &Inst, unsigned Insn,
1586                                  uint64_t Address, const void *Decoder) {
1587   DecodeStatus S = MCDisassembler::Success;
1588 
1589   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1590   unsigned mode = fieldFromInstruction32(Insn, 23, 2);
1591 
1592   switch (mode) {
1593     case 0:
1594       mode = ARM_AM::da;
1595       break;
1596     case 1:
1597       mode = ARM_AM::ia;
1598       break;
1599     case 2:
1600       mode = ARM_AM::db;
1601       break;
1602     case 3:
1603       mode = ARM_AM::ib;
1604       break;
1605   }
1606 
1607   Inst.addOperand(MCOperand::CreateImm(mode));
1608   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1609     return MCDisassembler::Fail;
1610 
1611   return S;
1612 }
1613 
1614 static DecodeStatus DecodeMemMultipleWritebackInstruction(llvm::MCInst &Inst,
1615                                   unsigned Insn,
1616                                   uint64_t Address, const void *Decoder) {
1617   DecodeStatus S = MCDisassembler::Success;
1618 
1619   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1620   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1621   unsigned reglist = fieldFromInstruction32(Insn, 0, 16);
1622 
1623   if (pred == 0xF) {
1624     switch (Inst.getOpcode()) {
1625       case ARM::LDMDA:
1626         Inst.setOpcode(ARM::RFEDA);
1627         break;
1628       case ARM::LDMDA_UPD:
1629         Inst.setOpcode(ARM::RFEDA_UPD);
1630         break;
1631       case ARM::LDMDB:
1632         Inst.setOpcode(ARM::RFEDB);
1633         break;
1634       case ARM::LDMDB_UPD:
1635         Inst.setOpcode(ARM::RFEDB_UPD);
1636         break;
1637       case ARM::LDMIA:
1638         Inst.setOpcode(ARM::RFEIA);
1639         break;
1640       case ARM::LDMIA_UPD:
1641         Inst.setOpcode(ARM::RFEIA_UPD);
1642         break;
1643       case ARM::LDMIB:
1644         Inst.setOpcode(ARM::RFEIB);
1645         break;
1646       case ARM::LDMIB_UPD:
1647         Inst.setOpcode(ARM::RFEIB_UPD);
1648         break;
1649       case ARM::STMDA:
1650         Inst.setOpcode(ARM::SRSDA);
1651         break;
1652       case ARM::STMDA_UPD:
1653         Inst.setOpcode(ARM::SRSDA_UPD);
1654         break;
1655       case ARM::STMDB:
1656         Inst.setOpcode(ARM::SRSDB);
1657         break;
1658       case ARM::STMDB_UPD:
1659         Inst.setOpcode(ARM::SRSDB_UPD);
1660         break;
1661       case ARM::STMIA:
1662         Inst.setOpcode(ARM::SRSIA);
1663         break;
1664       case ARM::STMIA_UPD:
1665         Inst.setOpcode(ARM::SRSIA_UPD);
1666         break;
1667       case ARM::STMIB:
1668         Inst.setOpcode(ARM::SRSIB);
1669         break;
1670       case ARM::STMIB_UPD:
1671         Inst.setOpcode(ARM::SRSIB_UPD);
1672         break;
1673       default:
1674         if (!Check(S, MCDisassembler::Fail)) return MCDisassembler::Fail;
1675     }
1676 
1677     // For stores (which become SRS's, the only operand is the mode.
1678     if (fieldFromInstruction32(Insn, 20, 1) == 0) {
1679       Inst.addOperand(
1680           MCOperand::CreateImm(fieldFromInstruction32(Insn, 0, 4)));
1681       return S;
1682     }
1683 
1684     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
1685   }
1686 
1687   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1688     return MCDisassembler::Fail;
1689   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1690     return MCDisassembler::Fail; // Tied
1691   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1692     return MCDisassembler::Fail;
1693   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
1694     return MCDisassembler::Fail;
1695 
1696   return S;
1697 }
1698 
1699 static DecodeStatus DecodeCPSInstruction(llvm::MCInst &Inst, unsigned Insn,
1700                                  uint64_t Address, const void *Decoder) {
1701   unsigned imod = fieldFromInstruction32(Insn, 18, 2);
1702   unsigned M = fieldFromInstruction32(Insn, 17, 1);
1703   unsigned iflags = fieldFromInstruction32(Insn, 6, 3);
1704   unsigned mode = fieldFromInstruction32(Insn, 0, 5);
1705 
1706   DecodeStatus S = MCDisassembler::Success;
1707 
1708   // imod == '01' --> UNPREDICTABLE
1709   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
1710   // return failure here.  The '01' imod value is unprintable, so there's
1711   // nothing useful we could do even if we returned UNPREDICTABLE.
1712 
1713   if (imod == 1) return MCDisassembler::Fail;
1714 
1715   if (imod && M) {
1716     Inst.setOpcode(ARM::CPS3p);
1717     Inst.addOperand(MCOperand::CreateImm(imod));
1718     Inst.addOperand(MCOperand::CreateImm(iflags));
1719     Inst.addOperand(MCOperand::CreateImm(mode));
1720   } else if (imod && !M) {
1721     Inst.setOpcode(ARM::CPS2p);
1722     Inst.addOperand(MCOperand::CreateImm(imod));
1723     Inst.addOperand(MCOperand::CreateImm(iflags));
1724     if (mode) S = MCDisassembler::SoftFail;
1725   } else if (!imod && M) {
1726     Inst.setOpcode(ARM::CPS1p);
1727     Inst.addOperand(MCOperand::CreateImm(mode));
1728     if (iflags) S = MCDisassembler::SoftFail;
1729   } else {
1730     // imod == '00' && M == '0' --> UNPREDICTABLE
1731     Inst.setOpcode(ARM::CPS1p);
1732     Inst.addOperand(MCOperand::CreateImm(mode));
1733     S = MCDisassembler::SoftFail;
1734   }
1735 
1736   return S;
1737 }
1738 
1739 static DecodeStatus DecodeT2CPSInstruction(llvm::MCInst &Inst, unsigned Insn,
1740                                  uint64_t Address, const void *Decoder) {
1741   unsigned imod = fieldFromInstruction32(Insn, 9, 2);
1742   unsigned M = fieldFromInstruction32(Insn, 8, 1);
1743   unsigned iflags = fieldFromInstruction32(Insn, 5, 3);
1744   unsigned mode = fieldFromInstruction32(Insn, 0, 5);
1745 
1746   DecodeStatus S = MCDisassembler::Success;
1747 
1748   // imod == '01' --> UNPREDICTABLE
1749   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
1750   // return failure here.  The '01' imod value is unprintable, so there's
1751   // nothing useful we could do even if we returned UNPREDICTABLE.
1752 
1753   if (imod == 1) return MCDisassembler::Fail;
1754 
1755   if (imod && M) {
1756     Inst.setOpcode(ARM::t2CPS3p);
1757     Inst.addOperand(MCOperand::CreateImm(imod));
1758     Inst.addOperand(MCOperand::CreateImm(iflags));
1759     Inst.addOperand(MCOperand::CreateImm(mode));
1760   } else if (imod && !M) {
1761     Inst.setOpcode(ARM::t2CPS2p);
1762     Inst.addOperand(MCOperand::CreateImm(imod));
1763     Inst.addOperand(MCOperand::CreateImm(iflags));
1764     if (mode) S = MCDisassembler::SoftFail;
1765   } else if (!imod && M) {
1766     Inst.setOpcode(ARM::t2CPS1p);
1767     Inst.addOperand(MCOperand::CreateImm(mode));
1768     if (iflags) S = MCDisassembler::SoftFail;
1769   } else {
1770     // imod == '00' && M == '0' --> UNPREDICTABLE
1771     Inst.setOpcode(ARM::t2CPS1p);
1772     Inst.addOperand(MCOperand::CreateImm(mode));
1773     S = MCDisassembler::SoftFail;
1774   }
1775 
1776   return S;
1777 }
1778 
1779 static DecodeStatus DecodeT2MOVTWInstruction(llvm::MCInst &Inst, unsigned Insn,
1780                                  uint64_t Address, const void *Decoder) {
1781   DecodeStatus S = MCDisassembler::Success;
1782 
1783   unsigned Rd = fieldFromInstruction32(Insn, 8, 4);
1784   unsigned imm = 0;
1785 
1786   imm |= (fieldFromInstruction32(Insn, 0, 8) << 0);
1787   imm |= (fieldFromInstruction32(Insn, 12, 3) << 8);
1788   imm |= (fieldFromInstruction32(Insn, 16, 4) << 12);
1789   imm |= (fieldFromInstruction32(Insn, 26, 1) << 11);
1790 
1791   if (Inst.getOpcode() == ARM::t2MOVTi16)
1792     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
1793       return MCDisassembler::Fail;
1794   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
1795     return MCDisassembler::Fail;
1796 
1797   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
1798     Inst.addOperand(MCOperand::CreateImm(imm));
1799 
1800   return S;
1801 }
1802 
1803 static DecodeStatus DecodeArmMOVTWInstruction(llvm::MCInst &Inst, unsigned Insn,
1804                                  uint64_t Address, const void *Decoder) {
1805   DecodeStatus S = MCDisassembler::Success;
1806 
1807   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1808   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1809   unsigned imm = 0;
1810 
1811   imm |= (fieldFromInstruction32(Insn, 0, 12) << 0);
1812   imm |= (fieldFromInstruction32(Insn, 16, 4) << 12);
1813 
1814   if (Inst.getOpcode() == ARM::MOVTi16)
1815     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
1816       return MCDisassembler::Fail;
1817   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
1818     return MCDisassembler::Fail;
1819 
1820   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
1821     Inst.addOperand(MCOperand::CreateImm(imm));
1822 
1823   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1824     return MCDisassembler::Fail;
1825 
1826   return S;
1827 }
1828 
1829 static DecodeStatus DecodeSMLAInstruction(llvm::MCInst &Inst, unsigned Insn,
1830                                  uint64_t Address, const void *Decoder) {
1831   DecodeStatus S = MCDisassembler::Success;
1832 
1833   unsigned Rd = fieldFromInstruction32(Insn, 16, 4);
1834   unsigned Rn = fieldFromInstruction32(Insn, 0, 4);
1835   unsigned Rm = fieldFromInstruction32(Insn, 8, 4);
1836   unsigned Ra = fieldFromInstruction32(Insn, 12, 4);
1837   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1838 
1839   if (pred == 0xF)
1840     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
1841 
1842   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
1843     return MCDisassembler::Fail;
1844   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
1845     return MCDisassembler::Fail;
1846   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1847     return MCDisassembler::Fail;
1848   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
1849     return MCDisassembler::Fail;
1850 
1851   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1852     return MCDisassembler::Fail;
1853 
1854   return S;
1855 }
1856 
1857 static DecodeStatus DecodeAddrModeImm12Operand(llvm::MCInst &Inst, unsigned Val,
1858                            uint64_t Address, const void *Decoder) {
1859   DecodeStatus S = MCDisassembler::Success;
1860 
1861   unsigned add = fieldFromInstruction32(Val, 12, 1);
1862   unsigned imm = fieldFromInstruction32(Val, 0, 12);
1863   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
1864 
1865   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1866     return MCDisassembler::Fail;
1867 
1868   if (!add) imm *= -1;
1869   if (imm == 0 && !add) imm = INT32_MIN;
1870   Inst.addOperand(MCOperand::CreateImm(imm));
1871   if (Rn == 15)
1872     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
1873 
1874   return S;
1875 }
1876 
1877 static DecodeStatus DecodeAddrMode5Operand(llvm::MCInst &Inst, unsigned Val,
1878                                    uint64_t Address, const void *Decoder) {
1879   DecodeStatus S = MCDisassembler::Success;
1880 
1881   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
1882   unsigned U = fieldFromInstruction32(Val, 8, 1);
1883   unsigned imm = fieldFromInstruction32(Val, 0, 8);
1884 
1885   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1886     return MCDisassembler::Fail;
1887 
1888   if (U)
1889     Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
1890   else
1891     Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
1892 
1893   return S;
1894 }
1895 
1896 static DecodeStatus DecodeAddrMode7Operand(llvm::MCInst &Inst, unsigned Val,
1897                                    uint64_t Address, const void *Decoder) {
1898   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
1899 }
1900 
1901 static DecodeStatus
1902 DecodeBranchImmInstruction(llvm::MCInst &Inst, unsigned Insn,
1903                            uint64_t Address, const void *Decoder) {
1904   DecodeStatus S = MCDisassembler::Success;
1905 
1906   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1907   unsigned imm = fieldFromInstruction32(Insn, 0, 24) << 2;
1908 
1909   if (pred == 0xF) {
1910     Inst.setOpcode(ARM::BLXi);
1911     imm |= fieldFromInstruction32(Insn, 24, 1) << 1;
1912     Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1913     return S;
1914   }
1915 
1916   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8, true,
1917                                 4, Inst, Decoder))
1918     Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1919   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1920     return MCDisassembler::Fail;
1921 
1922   return S;
1923 }
1924 
1925 
1926 static DecodeStatus DecodeVCVTImmOperand(llvm::MCInst &Inst, unsigned Val,
1927                                  uint64_t Address, const void *Decoder) {
1928   Inst.addOperand(MCOperand::CreateImm(64 - Val));
1929   return MCDisassembler::Success;
1930 }
1931 
1932 static DecodeStatus DecodeAddrMode6Operand(llvm::MCInst &Inst, unsigned Val,
1933                                    uint64_t Address, const void *Decoder) {
1934   DecodeStatus S = MCDisassembler::Success;
1935 
1936   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
1937   unsigned align = fieldFromInstruction32(Val, 4, 2);
1938 
1939   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1940     return MCDisassembler::Fail;
1941   if (!align)
1942     Inst.addOperand(MCOperand::CreateImm(0));
1943   else
1944     Inst.addOperand(MCOperand::CreateImm(4 << align));
1945 
1946   return S;
1947 }
1948 
1949 static DecodeStatus DecodeVLDInstruction(llvm::MCInst &Inst, unsigned Insn,
1950                                    uint64_t Address, const void *Decoder) {
1951   DecodeStatus S = MCDisassembler::Success;
1952 
1953   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1954   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1955   unsigned wb = fieldFromInstruction32(Insn, 16, 4);
1956   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1957   Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
1958   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1959 
1960   // First output register
1961   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
1962     return MCDisassembler::Fail;
1963 
1964   // Second output register
1965   switch (Inst.getOpcode()) {
1966     case ARM::VLD1q8:
1967     case ARM::VLD1q16:
1968     case ARM::VLD1q32:
1969     case ARM::VLD1q64:
1970     case ARM::VLD1q8_UPD:
1971     case ARM::VLD1q16_UPD:
1972     case ARM::VLD1q32_UPD:
1973     case ARM::VLD1q64_UPD:
1974     case ARM::VLD1d8T:
1975     case ARM::VLD1d16T:
1976     case ARM::VLD1d32T:
1977     case ARM::VLD1d64T:
1978     case ARM::VLD1d8T_UPD:
1979     case ARM::VLD1d16T_UPD:
1980     case ARM::VLD1d32T_UPD:
1981     case ARM::VLD1d64T_UPD:
1982     case ARM::VLD1d8Q:
1983     case ARM::VLD1d16Q:
1984     case ARM::VLD1d32Q:
1985     case ARM::VLD1d64Q:
1986     case ARM::VLD1d8Q_UPD:
1987     case ARM::VLD1d16Q_UPD:
1988     case ARM::VLD1d32Q_UPD:
1989     case ARM::VLD1d64Q_UPD:
1990     case ARM::VLD2d8:
1991     case ARM::VLD2d16:
1992     case ARM::VLD2d32:
1993     case ARM::VLD2d8_UPD:
1994     case ARM::VLD2d16_UPD:
1995     case ARM::VLD2d32_UPD:
1996     case ARM::VLD2q8:
1997     case ARM::VLD2q16:
1998     case ARM::VLD2q32:
1999     case ARM::VLD2q8_UPD:
2000     case ARM::VLD2q16_UPD:
2001     case ARM::VLD2q32_UPD:
2002     case ARM::VLD3d8:
2003     case ARM::VLD3d16:
2004     case ARM::VLD3d32:
2005     case ARM::VLD3d8_UPD:
2006     case ARM::VLD3d16_UPD:
2007     case ARM::VLD3d32_UPD:
2008     case ARM::VLD4d8:
2009     case ARM::VLD4d16:
2010     case ARM::VLD4d32:
2011     case ARM::VLD4d8_UPD:
2012     case ARM::VLD4d16_UPD:
2013     case ARM::VLD4d32_UPD:
2014       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2015         return MCDisassembler::Fail;
2016       break;
2017     case ARM::VLD2b8:
2018     case ARM::VLD2b16:
2019     case ARM::VLD2b32:
2020     case ARM::VLD2b8_UPD:
2021     case ARM::VLD2b16_UPD:
2022     case ARM::VLD2b32_UPD:
2023     case ARM::VLD3q8:
2024     case ARM::VLD3q16:
2025     case ARM::VLD3q32:
2026     case ARM::VLD3q8_UPD:
2027     case ARM::VLD3q16_UPD:
2028     case ARM::VLD3q32_UPD:
2029     case ARM::VLD4q8:
2030     case ARM::VLD4q16:
2031     case ARM::VLD4q32:
2032     case ARM::VLD4q8_UPD:
2033     case ARM::VLD4q16_UPD:
2034     case ARM::VLD4q32_UPD:
2035       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2036         return MCDisassembler::Fail;
2037     default:
2038       break;
2039   }
2040 
2041   // Third output register
2042   switch(Inst.getOpcode()) {
2043     case ARM::VLD1d8T:
2044     case ARM::VLD1d16T:
2045     case ARM::VLD1d32T:
2046     case ARM::VLD1d64T:
2047     case ARM::VLD1d8T_UPD:
2048     case ARM::VLD1d16T_UPD:
2049     case ARM::VLD1d32T_UPD:
2050     case ARM::VLD1d64T_UPD:
2051     case ARM::VLD1d8Q:
2052     case ARM::VLD1d16Q:
2053     case ARM::VLD1d32Q:
2054     case ARM::VLD1d64Q:
2055     case ARM::VLD1d8Q_UPD:
2056     case ARM::VLD1d16Q_UPD:
2057     case ARM::VLD1d32Q_UPD:
2058     case ARM::VLD1d64Q_UPD:
2059     case ARM::VLD2q8:
2060     case ARM::VLD2q16:
2061     case ARM::VLD2q32:
2062     case ARM::VLD2q8_UPD:
2063     case ARM::VLD2q16_UPD:
2064     case ARM::VLD2q32_UPD:
2065     case ARM::VLD3d8:
2066     case ARM::VLD3d16:
2067     case ARM::VLD3d32:
2068     case ARM::VLD3d8_UPD:
2069     case ARM::VLD3d16_UPD:
2070     case ARM::VLD3d32_UPD:
2071     case ARM::VLD4d8:
2072     case ARM::VLD4d16:
2073     case ARM::VLD4d32:
2074     case ARM::VLD4d8_UPD:
2075     case ARM::VLD4d16_UPD:
2076     case ARM::VLD4d32_UPD:
2077       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2078         return MCDisassembler::Fail;
2079       break;
2080     case ARM::VLD3q8:
2081     case ARM::VLD3q16:
2082     case ARM::VLD3q32:
2083     case ARM::VLD3q8_UPD:
2084     case ARM::VLD3q16_UPD:
2085     case ARM::VLD3q32_UPD:
2086     case ARM::VLD4q8:
2087     case ARM::VLD4q16:
2088     case ARM::VLD4q32:
2089     case ARM::VLD4q8_UPD:
2090     case ARM::VLD4q16_UPD:
2091     case ARM::VLD4q32_UPD:
2092       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2093         return MCDisassembler::Fail;
2094       break;
2095     default:
2096       break;
2097   }
2098 
2099   // Fourth output register
2100   switch (Inst.getOpcode()) {
2101     case ARM::VLD1d8Q:
2102     case ARM::VLD1d16Q:
2103     case ARM::VLD1d32Q:
2104     case ARM::VLD1d64Q:
2105     case ARM::VLD1d8Q_UPD:
2106     case ARM::VLD1d16Q_UPD:
2107     case ARM::VLD1d32Q_UPD:
2108     case ARM::VLD1d64Q_UPD:
2109     case ARM::VLD2q8:
2110     case ARM::VLD2q16:
2111     case ARM::VLD2q32:
2112     case ARM::VLD2q8_UPD:
2113     case ARM::VLD2q16_UPD:
2114     case ARM::VLD2q32_UPD:
2115     case ARM::VLD4d8:
2116     case ARM::VLD4d16:
2117     case ARM::VLD4d32:
2118     case ARM::VLD4d8_UPD:
2119     case ARM::VLD4d16_UPD:
2120     case ARM::VLD4d32_UPD:
2121       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2122         return MCDisassembler::Fail;
2123       break;
2124     case ARM::VLD4q8:
2125     case ARM::VLD4q16:
2126     case ARM::VLD4q32:
2127     case ARM::VLD4q8_UPD:
2128     case ARM::VLD4q16_UPD:
2129     case ARM::VLD4q32_UPD:
2130       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2131         return MCDisassembler::Fail;
2132       break;
2133     default:
2134       break;
2135   }
2136 
2137   // Writeback operand
2138   switch (Inst.getOpcode()) {
2139     case ARM::VLD1d8_UPD:
2140     case ARM::VLD1d16_UPD:
2141     case ARM::VLD1d32_UPD:
2142     case ARM::VLD1d64_UPD:
2143     case ARM::VLD1q8_UPD:
2144     case ARM::VLD1q16_UPD:
2145     case ARM::VLD1q32_UPD:
2146     case ARM::VLD1q64_UPD:
2147     case ARM::VLD1d8T_UPD:
2148     case ARM::VLD1d16T_UPD:
2149     case ARM::VLD1d32T_UPD:
2150     case ARM::VLD1d64T_UPD:
2151     case ARM::VLD1d8Q_UPD:
2152     case ARM::VLD1d16Q_UPD:
2153     case ARM::VLD1d32Q_UPD:
2154     case ARM::VLD1d64Q_UPD:
2155     case ARM::VLD2d8_UPD:
2156     case ARM::VLD2d16_UPD:
2157     case ARM::VLD2d32_UPD:
2158     case ARM::VLD2q8_UPD:
2159     case ARM::VLD2q16_UPD:
2160     case ARM::VLD2q32_UPD:
2161     case ARM::VLD2b8_UPD:
2162     case ARM::VLD2b16_UPD:
2163     case ARM::VLD2b32_UPD:
2164     case ARM::VLD3d8_UPD:
2165     case ARM::VLD3d16_UPD:
2166     case ARM::VLD3d32_UPD:
2167     case ARM::VLD3q8_UPD:
2168     case ARM::VLD3q16_UPD:
2169     case ARM::VLD3q32_UPD:
2170     case ARM::VLD4d8_UPD:
2171     case ARM::VLD4d16_UPD:
2172     case ARM::VLD4d32_UPD:
2173     case ARM::VLD4q8_UPD:
2174     case ARM::VLD4q16_UPD:
2175     case ARM::VLD4q32_UPD:
2176       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2177         return MCDisassembler::Fail;
2178       break;
2179     default:
2180       break;
2181   }
2182 
2183   // AddrMode6 Base (register+alignment)
2184   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2185     return MCDisassembler::Fail;
2186 
2187   // AddrMode6 Offset (register)
2188   if (Rm == 0xD)
2189     Inst.addOperand(MCOperand::CreateReg(0));
2190   else if (Rm != 0xF) {
2191     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2192       return MCDisassembler::Fail;
2193   }
2194 
2195   return S;
2196 }
2197 
2198 static DecodeStatus DecodeVSTInstruction(llvm::MCInst &Inst, unsigned Insn,
2199                                  uint64_t Address, const void *Decoder) {
2200   DecodeStatus S = MCDisassembler::Success;
2201 
2202   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2203   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2204   unsigned wb = fieldFromInstruction32(Insn, 16, 4);
2205   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2206   Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
2207   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2208 
2209   // Writeback Operand
2210   switch (Inst.getOpcode()) {
2211     case ARM::VST1d8_UPD:
2212     case ARM::VST1d16_UPD:
2213     case ARM::VST1d32_UPD:
2214     case ARM::VST1d64_UPD:
2215     case ARM::VST1q8_UPD:
2216     case ARM::VST1q16_UPD:
2217     case ARM::VST1q32_UPD:
2218     case ARM::VST1q64_UPD:
2219     case ARM::VST1d8T_UPD:
2220     case ARM::VST1d16T_UPD:
2221     case ARM::VST1d32T_UPD:
2222     case ARM::VST1d64T_UPD:
2223     case ARM::VST1d8Q_UPD:
2224     case ARM::VST1d16Q_UPD:
2225     case ARM::VST1d32Q_UPD:
2226     case ARM::VST1d64Q_UPD:
2227     case ARM::VST2d8_UPD:
2228     case ARM::VST2d16_UPD:
2229     case ARM::VST2d32_UPD:
2230     case ARM::VST2q8_UPD:
2231     case ARM::VST2q16_UPD:
2232     case ARM::VST2q32_UPD:
2233     case ARM::VST2b8_UPD:
2234     case ARM::VST2b16_UPD:
2235     case ARM::VST2b32_UPD:
2236     case ARM::VST3d8_UPD:
2237     case ARM::VST3d16_UPD:
2238     case ARM::VST3d32_UPD:
2239     case ARM::VST3q8_UPD:
2240     case ARM::VST3q16_UPD:
2241     case ARM::VST3q32_UPD:
2242     case ARM::VST4d8_UPD:
2243     case ARM::VST4d16_UPD:
2244     case ARM::VST4d32_UPD:
2245     case ARM::VST4q8_UPD:
2246     case ARM::VST4q16_UPD:
2247     case ARM::VST4q32_UPD:
2248       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2249         return MCDisassembler::Fail;
2250       break;
2251     default:
2252       break;
2253   }
2254 
2255   // AddrMode6 Base (register+alignment)
2256   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2257     return MCDisassembler::Fail;
2258 
2259   // AddrMode6 Offset (register)
2260   if (Rm == 0xD)
2261     Inst.addOperand(MCOperand::CreateReg(0));
2262   else if (Rm != 0xF) {
2263     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2264     return MCDisassembler::Fail;
2265   }
2266 
2267   // First input register
2268   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2269     return MCDisassembler::Fail;
2270 
2271   // Second input register
2272   switch (Inst.getOpcode()) {
2273     case ARM::VST1q8:
2274     case ARM::VST1q16:
2275     case ARM::VST1q32:
2276     case ARM::VST1q64:
2277     case ARM::VST1q8_UPD:
2278     case ARM::VST1q16_UPD:
2279     case ARM::VST1q32_UPD:
2280     case ARM::VST1q64_UPD:
2281     case ARM::VST1d8T:
2282     case ARM::VST1d16T:
2283     case ARM::VST1d32T:
2284     case ARM::VST1d64T:
2285     case ARM::VST1d8T_UPD:
2286     case ARM::VST1d16T_UPD:
2287     case ARM::VST1d32T_UPD:
2288     case ARM::VST1d64T_UPD:
2289     case ARM::VST1d8Q:
2290     case ARM::VST1d16Q:
2291     case ARM::VST1d32Q:
2292     case ARM::VST1d64Q:
2293     case ARM::VST1d8Q_UPD:
2294     case ARM::VST1d16Q_UPD:
2295     case ARM::VST1d32Q_UPD:
2296     case ARM::VST1d64Q_UPD:
2297     case ARM::VST2d8:
2298     case ARM::VST2d16:
2299     case ARM::VST2d32:
2300     case ARM::VST2d8_UPD:
2301     case ARM::VST2d16_UPD:
2302     case ARM::VST2d32_UPD:
2303     case ARM::VST2q8:
2304     case ARM::VST2q16:
2305     case ARM::VST2q32:
2306     case ARM::VST2q8_UPD:
2307     case ARM::VST2q16_UPD:
2308     case ARM::VST2q32_UPD:
2309     case ARM::VST3d8:
2310     case ARM::VST3d16:
2311     case ARM::VST3d32:
2312     case ARM::VST3d8_UPD:
2313     case ARM::VST3d16_UPD:
2314     case ARM::VST3d32_UPD:
2315     case ARM::VST4d8:
2316     case ARM::VST4d16:
2317     case ARM::VST4d32:
2318     case ARM::VST4d8_UPD:
2319     case ARM::VST4d16_UPD:
2320     case ARM::VST4d32_UPD:
2321       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2322         return MCDisassembler::Fail;
2323       break;
2324     case ARM::VST2b8:
2325     case ARM::VST2b16:
2326     case ARM::VST2b32:
2327     case ARM::VST2b8_UPD:
2328     case ARM::VST2b16_UPD:
2329     case ARM::VST2b32_UPD:
2330     case ARM::VST3q8:
2331     case ARM::VST3q16:
2332     case ARM::VST3q32:
2333     case ARM::VST3q8_UPD:
2334     case ARM::VST3q16_UPD:
2335     case ARM::VST3q32_UPD:
2336     case ARM::VST4q8:
2337     case ARM::VST4q16:
2338     case ARM::VST4q32:
2339     case ARM::VST4q8_UPD:
2340     case ARM::VST4q16_UPD:
2341     case ARM::VST4q32_UPD:
2342       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2343         return MCDisassembler::Fail;
2344       break;
2345     default:
2346       break;
2347   }
2348 
2349   // Third input register
2350   switch (Inst.getOpcode()) {
2351     case ARM::VST1d8T:
2352     case ARM::VST1d16T:
2353     case ARM::VST1d32T:
2354     case ARM::VST1d64T:
2355     case ARM::VST1d8T_UPD:
2356     case ARM::VST1d16T_UPD:
2357     case ARM::VST1d32T_UPD:
2358     case ARM::VST1d64T_UPD:
2359     case ARM::VST1d8Q:
2360     case ARM::VST1d16Q:
2361     case ARM::VST1d32Q:
2362     case ARM::VST1d64Q:
2363     case ARM::VST1d8Q_UPD:
2364     case ARM::VST1d16Q_UPD:
2365     case ARM::VST1d32Q_UPD:
2366     case ARM::VST1d64Q_UPD:
2367     case ARM::VST2q8:
2368     case ARM::VST2q16:
2369     case ARM::VST2q32:
2370     case ARM::VST2q8_UPD:
2371     case ARM::VST2q16_UPD:
2372     case ARM::VST2q32_UPD:
2373     case ARM::VST3d8:
2374     case ARM::VST3d16:
2375     case ARM::VST3d32:
2376     case ARM::VST3d8_UPD:
2377     case ARM::VST3d16_UPD:
2378     case ARM::VST3d32_UPD:
2379     case ARM::VST4d8:
2380     case ARM::VST4d16:
2381     case ARM::VST4d32:
2382     case ARM::VST4d8_UPD:
2383     case ARM::VST4d16_UPD:
2384     case ARM::VST4d32_UPD:
2385       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2386         return MCDisassembler::Fail;
2387       break;
2388     case ARM::VST3q8:
2389     case ARM::VST3q16:
2390     case ARM::VST3q32:
2391     case ARM::VST3q8_UPD:
2392     case ARM::VST3q16_UPD:
2393     case ARM::VST3q32_UPD:
2394     case ARM::VST4q8:
2395     case ARM::VST4q16:
2396     case ARM::VST4q32:
2397     case ARM::VST4q8_UPD:
2398     case ARM::VST4q16_UPD:
2399     case ARM::VST4q32_UPD:
2400       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2401         return MCDisassembler::Fail;
2402       break;
2403     default:
2404       break;
2405   }
2406 
2407   // Fourth input register
2408   switch (Inst.getOpcode()) {
2409     case ARM::VST1d8Q:
2410     case ARM::VST1d16Q:
2411     case ARM::VST1d32Q:
2412     case ARM::VST1d64Q:
2413     case ARM::VST1d8Q_UPD:
2414     case ARM::VST1d16Q_UPD:
2415     case ARM::VST1d32Q_UPD:
2416     case ARM::VST1d64Q_UPD:
2417     case ARM::VST2q8:
2418     case ARM::VST2q16:
2419     case ARM::VST2q32:
2420     case ARM::VST2q8_UPD:
2421     case ARM::VST2q16_UPD:
2422     case ARM::VST2q32_UPD:
2423     case ARM::VST4d8:
2424     case ARM::VST4d16:
2425     case ARM::VST4d32:
2426     case ARM::VST4d8_UPD:
2427     case ARM::VST4d16_UPD:
2428     case ARM::VST4d32_UPD:
2429       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2430         return MCDisassembler::Fail;
2431       break;
2432     case ARM::VST4q8:
2433     case ARM::VST4q16:
2434     case ARM::VST4q32:
2435     case ARM::VST4q8_UPD:
2436     case ARM::VST4q16_UPD:
2437     case ARM::VST4q32_UPD:
2438       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2439         return MCDisassembler::Fail;
2440       break;
2441     default:
2442       break;
2443   }
2444 
2445   return S;
2446 }
2447 
2448 static DecodeStatus DecodeVLD1DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2449                                     uint64_t Address, const void *Decoder) {
2450   DecodeStatus S = MCDisassembler::Success;
2451 
2452   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2453   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2454   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2455   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2456   unsigned align = fieldFromInstruction32(Insn, 4, 1);
2457   unsigned size = fieldFromInstruction32(Insn, 6, 2);
2458   unsigned regs = fieldFromInstruction32(Insn, 5, 1) + 1;
2459 
2460   align *= (1 << size);
2461 
2462   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2463     return MCDisassembler::Fail;
2464   if (regs == 2) {
2465     if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2466       return MCDisassembler::Fail;
2467   }
2468   if (Rm != 0xF) {
2469     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2470       return MCDisassembler::Fail;
2471   }
2472 
2473   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2474     return MCDisassembler::Fail;
2475   Inst.addOperand(MCOperand::CreateImm(align));
2476 
2477   if (Rm == 0xD)
2478     Inst.addOperand(MCOperand::CreateReg(0));
2479   else if (Rm != 0xF) {
2480     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2481       return MCDisassembler::Fail;
2482   }
2483 
2484   return S;
2485 }
2486 
2487 static DecodeStatus DecodeVLD2DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2488                                     uint64_t Address, const void *Decoder) {
2489   DecodeStatus S = MCDisassembler::Success;
2490 
2491   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2492   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2493   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2494   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2495   unsigned align = fieldFromInstruction32(Insn, 4, 1);
2496   unsigned size = 1 << fieldFromInstruction32(Insn, 6, 2);
2497   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2498   align *= 2*size;
2499 
2500   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2501     return MCDisassembler::Fail;
2502   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
2503     return MCDisassembler::Fail;
2504   if (Rm != 0xF) {
2505     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2506       return MCDisassembler::Fail;
2507   }
2508 
2509   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2510     return MCDisassembler::Fail;
2511   Inst.addOperand(MCOperand::CreateImm(align));
2512 
2513   if (Rm == 0xD)
2514     Inst.addOperand(MCOperand::CreateReg(0));
2515   else if (Rm != 0xF) {
2516     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2517       return MCDisassembler::Fail;
2518   }
2519 
2520   return S;
2521 }
2522 
2523 static DecodeStatus DecodeVLD3DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2524                                     uint64_t Address, const void *Decoder) {
2525   DecodeStatus S = MCDisassembler::Success;
2526 
2527   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2528   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2529   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2530   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2531   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2532 
2533   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2534     return MCDisassembler::Fail;
2535   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
2536     return MCDisassembler::Fail;
2537   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
2538     return MCDisassembler::Fail;
2539   if (Rm != 0xF) {
2540     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2541       return MCDisassembler::Fail;
2542   }
2543 
2544   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2545     return MCDisassembler::Fail;
2546   Inst.addOperand(MCOperand::CreateImm(0));
2547 
2548   if (Rm == 0xD)
2549     Inst.addOperand(MCOperand::CreateReg(0));
2550   else if (Rm != 0xF) {
2551     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2552       return MCDisassembler::Fail;
2553   }
2554 
2555   return S;
2556 }
2557 
2558 static DecodeStatus DecodeVLD4DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2559                                     uint64_t Address, const void *Decoder) {
2560   DecodeStatus S = MCDisassembler::Success;
2561 
2562   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2563   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2564   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2565   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2566   unsigned size = fieldFromInstruction32(Insn, 6, 2);
2567   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2568   unsigned align = fieldFromInstruction32(Insn, 4, 1);
2569 
2570   if (size == 0x3) {
2571     size = 4;
2572     align = 16;
2573   } else {
2574     if (size == 2) {
2575       size = 1 << size;
2576       align *= 8;
2577     } else {
2578       size = 1 << size;
2579       align *= 4*size;
2580     }
2581   }
2582 
2583   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2584     return MCDisassembler::Fail;
2585   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
2586     return MCDisassembler::Fail;
2587   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
2588     return MCDisassembler::Fail;
2589   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
2590     return MCDisassembler::Fail;
2591   if (Rm != 0xF) {
2592     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2593       return MCDisassembler::Fail;
2594   }
2595 
2596   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2597     return MCDisassembler::Fail;
2598   Inst.addOperand(MCOperand::CreateImm(align));
2599 
2600   if (Rm == 0xD)
2601     Inst.addOperand(MCOperand::CreateReg(0));
2602   else if (Rm != 0xF) {
2603     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2604       return MCDisassembler::Fail;
2605   }
2606 
2607   return S;
2608 }
2609 
2610 static DecodeStatus
2611 DecodeNEONModImmInstruction(llvm::MCInst &Inst, unsigned Insn,
2612                             uint64_t Address, const void *Decoder) {
2613   DecodeStatus S = MCDisassembler::Success;
2614 
2615   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2616   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2617   unsigned imm = fieldFromInstruction32(Insn, 0, 4);
2618   imm |= fieldFromInstruction32(Insn, 16, 3) << 4;
2619   imm |= fieldFromInstruction32(Insn, 24, 1) << 7;
2620   imm |= fieldFromInstruction32(Insn, 8, 4) << 8;
2621   imm |= fieldFromInstruction32(Insn, 5, 1) << 12;
2622   unsigned Q = fieldFromInstruction32(Insn, 6, 1);
2623 
2624   if (Q) {
2625     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
2626     return MCDisassembler::Fail;
2627   } else {
2628     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2629     return MCDisassembler::Fail;
2630   }
2631 
2632   Inst.addOperand(MCOperand::CreateImm(imm));
2633 
2634   switch (Inst.getOpcode()) {
2635     case ARM::VORRiv4i16:
2636     case ARM::VORRiv2i32:
2637     case ARM::VBICiv4i16:
2638     case ARM::VBICiv2i32:
2639       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2640         return MCDisassembler::Fail;
2641       break;
2642     case ARM::VORRiv8i16:
2643     case ARM::VORRiv4i32:
2644     case ARM::VBICiv8i16:
2645     case ARM::VBICiv4i32:
2646       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
2647         return MCDisassembler::Fail;
2648       break;
2649     default:
2650       break;
2651   }
2652 
2653   return S;
2654 }
2655 
2656 static DecodeStatus DecodeVSHLMaxInstruction(llvm::MCInst &Inst, unsigned Insn,
2657                                         uint64_t Address, const void *Decoder) {
2658   DecodeStatus S = MCDisassembler::Success;
2659 
2660   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2661   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2662   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2663   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2664   unsigned size = fieldFromInstruction32(Insn, 18, 2);
2665 
2666   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
2667     return MCDisassembler::Fail;
2668   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
2669     return MCDisassembler::Fail;
2670   Inst.addOperand(MCOperand::CreateImm(8 << size));
2671 
2672   return S;
2673 }
2674 
2675 static DecodeStatus DecodeShiftRight8Imm(llvm::MCInst &Inst, unsigned Val,
2676                                uint64_t Address, const void *Decoder) {
2677   Inst.addOperand(MCOperand::CreateImm(8 - Val));
2678   return MCDisassembler::Success;
2679 }
2680 
2681 static DecodeStatus DecodeShiftRight16Imm(llvm::MCInst &Inst, unsigned Val,
2682                                uint64_t Address, const void *Decoder) {
2683   Inst.addOperand(MCOperand::CreateImm(16 - Val));
2684   return MCDisassembler::Success;
2685 }
2686 
2687 static DecodeStatus DecodeShiftRight32Imm(llvm::MCInst &Inst, unsigned Val,
2688                                uint64_t Address, const void *Decoder) {
2689   Inst.addOperand(MCOperand::CreateImm(32 - Val));
2690   return MCDisassembler::Success;
2691 }
2692 
2693 static DecodeStatus DecodeShiftRight64Imm(llvm::MCInst &Inst, unsigned Val,
2694                                uint64_t Address, const void *Decoder) {
2695   Inst.addOperand(MCOperand::CreateImm(64 - Val));
2696   return MCDisassembler::Success;
2697 }
2698 
2699 static DecodeStatus DecodeTBLInstruction(llvm::MCInst &Inst, unsigned Insn,
2700                                uint64_t Address, const void *Decoder) {
2701   DecodeStatus S = MCDisassembler::Success;
2702 
2703   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2704   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2705   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2706   Rn |= fieldFromInstruction32(Insn, 7, 1) << 4;
2707   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2708   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2709   unsigned op = fieldFromInstruction32(Insn, 6, 1);
2710   unsigned length = fieldFromInstruction32(Insn, 8, 2) + 1;
2711 
2712   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2713     return MCDisassembler::Fail;
2714   if (op) {
2715     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2716     return MCDisassembler::Fail; // Writeback
2717   }
2718 
2719   for (unsigned i = 0; i < length; ++i) {
2720     if (!Check(S, DecodeDPRRegisterClass(Inst, (Rn+i)%32, Address, Decoder)))
2721     return MCDisassembler::Fail;
2722   }
2723 
2724   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
2725     return MCDisassembler::Fail;
2726 
2727   return S;
2728 }
2729 
2730 static DecodeStatus DecodeThumbAddSpecialReg(llvm::MCInst &Inst, uint16_t Insn,
2731                                      uint64_t Address, const void *Decoder) {
2732   DecodeStatus S = MCDisassembler::Success;
2733 
2734   unsigned dst = fieldFromInstruction16(Insn, 8, 3);
2735   unsigned imm = fieldFromInstruction16(Insn, 0, 8);
2736 
2737   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
2738     return MCDisassembler::Fail;
2739 
2740   switch(Inst.getOpcode()) {
2741     default:
2742       return MCDisassembler::Fail;
2743     case ARM::tADR:
2744       break; // tADR does not explicitly represent the PC as an operand.
2745     case ARM::tADDrSPi:
2746       Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2747       break;
2748   }
2749 
2750   Inst.addOperand(MCOperand::CreateImm(imm));
2751   return S;
2752 }
2753 
2754 static DecodeStatus DecodeThumbBROperand(llvm::MCInst &Inst, unsigned Val,
2755                                  uint64_t Address, const void *Decoder) {
2756   Inst.addOperand(MCOperand::CreateImm(SignExtend32<12>(Val << 1)));
2757   return MCDisassembler::Success;
2758 }
2759 
2760 static DecodeStatus DecodeT2BROperand(llvm::MCInst &Inst, unsigned Val,
2761                                  uint64_t Address, const void *Decoder) {
2762   Inst.addOperand(MCOperand::CreateImm(SignExtend32<21>(Val)));
2763   return MCDisassembler::Success;
2764 }
2765 
2766 static DecodeStatus DecodeThumbCmpBROperand(llvm::MCInst &Inst, unsigned Val,
2767                                  uint64_t Address, const void *Decoder) {
2768   Inst.addOperand(MCOperand::CreateImm(SignExtend32<7>(Val << 1)));
2769   return MCDisassembler::Success;
2770 }
2771 
2772 static DecodeStatus DecodeThumbAddrModeRR(llvm::MCInst &Inst, unsigned Val,
2773                                  uint64_t Address, const void *Decoder) {
2774   DecodeStatus S = MCDisassembler::Success;
2775 
2776   unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2777   unsigned Rm = fieldFromInstruction32(Val, 3, 3);
2778 
2779   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
2780     return MCDisassembler::Fail;
2781   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
2782     return MCDisassembler::Fail;
2783 
2784   return S;
2785 }
2786 
2787 static DecodeStatus DecodeThumbAddrModeIS(llvm::MCInst &Inst, unsigned Val,
2788                                   uint64_t Address, const void *Decoder) {
2789   DecodeStatus S = MCDisassembler::Success;
2790 
2791   unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2792   unsigned imm = fieldFromInstruction32(Val, 3, 5);
2793 
2794   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
2795     return MCDisassembler::Fail;
2796   Inst.addOperand(MCOperand::CreateImm(imm));
2797 
2798   return S;
2799 }
2800 
2801 static DecodeStatus DecodeThumbAddrModePC(llvm::MCInst &Inst, unsigned Val,
2802                                   uint64_t Address, const void *Decoder) {
2803   unsigned imm = Val << 2;
2804 
2805   Inst.addOperand(MCOperand::CreateImm(imm));
2806   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
2807 
2808   return MCDisassembler::Success;
2809 }
2810 
2811 static DecodeStatus DecodeThumbAddrModeSP(llvm::MCInst &Inst, unsigned Val,
2812                                   uint64_t Address, const void *Decoder) {
2813   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2814   Inst.addOperand(MCOperand::CreateImm(Val));
2815 
2816   return MCDisassembler::Success;
2817 }
2818 
2819 static DecodeStatus DecodeT2AddrModeSOReg(llvm::MCInst &Inst, unsigned Val,
2820                                   uint64_t Address, const void *Decoder) {
2821   DecodeStatus S = MCDisassembler::Success;
2822 
2823   unsigned Rn = fieldFromInstruction32(Val, 6, 4);
2824   unsigned Rm = fieldFromInstruction32(Val, 2, 4);
2825   unsigned imm = fieldFromInstruction32(Val, 0, 2);
2826 
2827   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2828     return MCDisassembler::Fail;
2829   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
2830     return MCDisassembler::Fail;
2831   Inst.addOperand(MCOperand::CreateImm(imm));
2832 
2833   return S;
2834 }
2835 
2836 static DecodeStatus DecodeT2LoadShift(llvm::MCInst &Inst, unsigned Insn,
2837                               uint64_t Address, const void *Decoder) {
2838   DecodeStatus S = MCDisassembler::Success;
2839 
2840   switch (Inst.getOpcode()) {
2841     case ARM::t2PLDs:
2842     case ARM::t2PLDWs:
2843     case ARM::t2PLIs:
2844       break;
2845     default: {
2846       unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2847       if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
2848     return MCDisassembler::Fail;
2849     }
2850   }
2851 
2852   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2853   if (Rn == 0xF) {
2854     switch (Inst.getOpcode()) {
2855       case ARM::t2LDRBs:
2856         Inst.setOpcode(ARM::t2LDRBpci);
2857         break;
2858       case ARM::t2LDRHs:
2859         Inst.setOpcode(ARM::t2LDRHpci);
2860         break;
2861       case ARM::t2LDRSHs:
2862         Inst.setOpcode(ARM::t2LDRSHpci);
2863         break;
2864       case ARM::t2LDRSBs:
2865         Inst.setOpcode(ARM::t2LDRSBpci);
2866         break;
2867       case ARM::t2PLDs:
2868         Inst.setOpcode(ARM::t2PLDi12);
2869         Inst.addOperand(MCOperand::CreateReg(ARM::PC));
2870         break;
2871       default:
2872         return MCDisassembler::Fail;
2873     }
2874 
2875     int imm = fieldFromInstruction32(Insn, 0, 12);
2876     if (!fieldFromInstruction32(Insn, 23, 1)) imm *= -1;
2877     Inst.addOperand(MCOperand::CreateImm(imm));
2878 
2879     return S;
2880   }
2881 
2882   unsigned addrmode = fieldFromInstruction32(Insn, 4, 2);
2883   addrmode |= fieldFromInstruction32(Insn, 0, 4) << 2;
2884   addrmode |= fieldFromInstruction32(Insn, 16, 4) << 6;
2885   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
2886     return MCDisassembler::Fail;
2887 
2888   return S;
2889 }
2890 
2891 static DecodeStatus DecodeT2Imm8S4(llvm::MCInst &Inst, unsigned Val,
2892                            uint64_t Address, const void *Decoder) {
2893   int imm = Val & 0xFF;
2894   if (!(Val & 0x100)) imm *= -1;
2895   Inst.addOperand(MCOperand::CreateImm(imm << 2));
2896 
2897   return MCDisassembler::Success;
2898 }
2899 
2900 static DecodeStatus DecodeT2AddrModeImm8s4(llvm::MCInst &Inst, unsigned Val,
2901                                    uint64_t Address, const void *Decoder) {
2902   DecodeStatus S = MCDisassembler::Success;
2903 
2904   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2905   unsigned imm = fieldFromInstruction32(Val, 0, 9);
2906 
2907   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2908     return MCDisassembler::Fail;
2909   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
2910     return MCDisassembler::Fail;
2911 
2912   return S;
2913 }
2914 
2915 static DecodeStatus DecodeT2AddrModeImm0_1020s4(llvm::MCInst &Inst,unsigned Val,
2916                                    uint64_t Address, const void *Decoder) {
2917   DecodeStatus S = MCDisassembler::Success;
2918 
2919   unsigned Rn = fieldFromInstruction32(Val, 8, 4);
2920   unsigned imm = fieldFromInstruction32(Val, 0, 8);
2921 
2922   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2923     return MCDisassembler::Fail;
2924 
2925   Inst.addOperand(MCOperand::CreateImm(imm));
2926 
2927   return S;
2928 }
2929 
2930 static DecodeStatus DecodeT2Imm8(llvm::MCInst &Inst, unsigned Val,
2931                          uint64_t Address, const void *Decoder) {
2932   int imm = Val & 0xFF;
2933   if (Val == 0)
2934     imm = INT32_MIN;
2935   else if (!(Val & 0x100))
2936     imm *= -1;
2937   Inst.addOperand(MCOperand::CreateImm(imm));
2938 
2939   return MCDisassembler::Success;
2940 }
2941 
2942 
2943 static DecodeStatus DecodeT2AddrModeImm8(llvm::MCInst &Inst, unsigned Val,
2944                                  uint64_t Address, const void *Decoder) {
2945   DecodeStatus S = MCDisassembler::Success;
2946 
2947   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2948   unsigned imm = fieldFromInstruction32(Val, 0, 9);
2949 
2950   // Some instructions always use an additive offset.
2951   switch (Inst.getOpcode()) {
2952     case ARM::t2LDRT:
2953     case ARM::t2LDRBT:
2954     case ARM::t2LDRHT:
2955     case ARM::t2LDRSBT:
2956     case ARM::t2LDRSHT:
2957     case ARM::t2STRT:
2958     case ARM::t2STRBT:
2959     case ARM::t2STRHT:
2960       imm |= 0x100;
2961       break;
2962     default:
2963       break;
2964   }
2965 
2966   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2967     return MCDisassembler::Fail;
2968   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
2969     return MCDisassembler::Fail;
2970 
2971   return S;
2972 }
2973 
2974 static DecodeStatus DecodeT2LdStPre(llvm::MCInst &Inst, unsigned Insn,
2975                                     uint64_t Address, const void *Decoder) {
2976   DecodeStatus S = MCDisassembler::Success;
2977 
2978   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2979   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2980   unsigned addr = fieldFromInstruction32(Insn, 0, 8);
2981   addr |= fieldFromInstruction32(Insn, 9, 1) << 8;
2982   addr |= Rn << 9;
2983   unsigned load = fieldFromInstruction32(Insn, 20, 1);
2984 
2985   if (!load) {
2986     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2987       return MCDisassembler::Fail;
2988   }
2989 
2990   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
2991     return MCDisassembler::Fail;
2992 
2993   if (load) {
2994     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2995       return MCDisassembler::Fail;
2996   }
2997 
2998   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
2999     return MCDisassembler::Fail;
3000 
3001   return S;
3002 }
3003 
3004 static DecodeStatus DecodeT2AddrModeImm12(llvm::MCInst &Inst, unsigned Val,
3005                                   uint64_t Address, const void *Decoder) {
3006   DecodeStatus S = MCDisassembler::Success;
3007 
3008   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
3009   unsigned imm = fieldFromInstruction32(Val, 0, 12);
3010 
3011   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3012     return MCDisassembler::Fail;
3013   Inst.addOperand(MCOperand::CreateImm(imm));
3014 
3015   return S;
3016 }
3017 
3018 
3019 static DecodeStatus DecodeThumbAddSPImm(llvm::MCInst &Inst, uint16_t Insn,
3020                                 uint64_t Address, const void *Decoder) {
3021   unsigned imm = fieldFromInstruction16(Insn, 0, 7);
3022 
3023   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
3024   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
3025   Inst.addOperand(MCOperand::CreateImm(imm));
3026 
3027   return MCDisassembler::Success;
3028 }
3029 
3030 static DecodeStatus DecodeThumbAddSPReg(llvm::MCInst &Inst, uint16_t Insn,
3031                                 uint64_t Address, const void *Decoder) {
3032   DecodeStatus S = MCDisassembler::Success;
3033 
3034   if (Inst.getOpcode() == ARM::tADDrSP) {
3035     unsigned Rdm = fieldFromInstruction16(Insn, 0, 3);
3036     Rdm |= fieldFromInstruction16(Insn, 7, 1) << 3;
3037 
3038     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
3039     return MCDisassembler::Fail;
3040     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
3041     return MCDisassembler::Fail;
3042     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
3043   } else if (Inst.getOpcode() == ARM::tADDspr) {
3044     unsigned Rm = fieldFromInstruction16(Insn, 3, 4);
3045 
3046     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
3047     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
3048     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3049     return MCDisassembler::Fail;
3050   }
3051 
3052   return S;
3053 }
3054 
3055 static DecodeStatus DecodeThumbCPS(llvm::MCInst &Inst, uint16_t Insn,
3056                            uint64_t Address, const void *Decoder) {
3057   unsigned imod = fieldFromInstruction16(Insn, 4, 1) | 0x2;
3058   unsigned flags = fieldFromInstruction16(Insn, 0, 3);
3059 
3060   Inst.addOperand(MCOperand::CreateImm(imod));
3061   Inst.addOperand(MCOperand::CreateImm(flags));
3062 
3063   return MCDisassembler::Success;
3064 }
3065 
3066 static DecodeStatus DecodePostIdxReg(llvm::MCInst &Inst, unsigned Insn,
3067                              uint64_t Address, const void *Decoder) {
3068   DecodeStatus S = MCDisassembler::Success;
3069   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3070   unsigned add = fieldFromInstruction32(Insn, 4, 1);
3071 
3072   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3073     return MCDisassembler::Fail;
3074   Inst.addOperand(MCOperand::CreateImm(add));
3075 
3076   return S;
3077 }
3078 
3079 static DecodeStatus DecodeThumbBLXOffset(llvm::MCInst &Inst, unsigned Val,
3080                                  uint64_t Address, const void *Decoder) {
3081   if (!tryAddingSymbolicOperand(Address,
3082                                 (Address & ~2u) + SignExtend32<22>(Val << 1) + 4,
3083                                 true, 4, Inst, Decoder))
3084     Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
3085   return MCDisassembler::Success;
3086 }
3087 
3088 static DecodeStatus DecodeCoprocessor(llvm::MCInst &Inst, unsigned Val,
3089                               uint64_t Address, const void *Decoder) {
3090   if (Val == 0xA || Val == 0xB)
3091     return MCDisassembler::Fail;
3092 
3093   Inst.addOperand(MCOperand::CreateImm(Val));
3094   return MCDisassembler::Success;
3095 }
3096 
3097 static DecodeStatus
3098 DecodeThumbTableBranch(llvm::MCInst &Inst, unsigned Insn,
3099                        uint64_t Address, const void *Decoder) {
3100   DecodeStatus S = MCDisassembler::Success;
3101 
3102   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3103   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3104 
3105   if (Rn == ARM::SP) S = MCDisassembler::SoftFail;
3106   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3107     return MCDisassembler::Fail;
3108   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3109     return MCDisassembler::Fail;
3110   return S;
3111 }
3112 
3113 static DecodeStatus
3114 DecodeThumb2BCCInstruction(llvm::MCInst &Inst, unsigned Insn,
3115                            uint64_t Address, const void *Decoder) {
3116   DecodeStatus S = MCDisassembler::Success;
3117 
3118   unsigned pred = fieldFromInstruction32(Insn, 22, 4);
3119   if (pred == 0xE || pred == 0xF) {
3120     unsigned opc = fieldFromInstruction32(Insn, 4, 28);
3121     switch (opc) {
3122       default:
3123         return MCDisassembler::Fail;
3124       case 0xf3bf8f4:
3125         Inst.setOpcode(ARM::t2DSB);
3126         break;
3127       case 0xf3bf8f5:
3128         Inst.setOpcode(ARM::t2DMB);
3129         break;
3130       case 0xf3bf8f6:
3131         Inst.setOpcode(ARM::t2ISB);
3132         break;
3133     }
3134 
3135     unsigned imm = fieldFromInstruction32(Insn, 0, 4);
3136     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
3137   }
3138 
3139   unsigned brtarget = fieldFromInstruction32(Insn, 0, 11) << 1;
3140   brtarget |= fieldFromInstruction32(Insn, 11, 1) << 19;
3141   brtarget |= fieldFromInstruction32(Insn, 13, 1) << 18;
3142   brtarget |= fieldFromInstruction32(Insn, 16, 6) << 12;
3143   brtarget |= fieldFromInstruction32(Insn, 26, 1) << 20;
3144 
3145   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
3146     return MCDisassembler::Fail;
3147   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3148     return MCDisassembler::Fail;
3149 
3150   return S;
3151 }
3152 
3153 // Decode a shifted immediate operand.  These basically consist
3154 // of an 8-bit value, and a 4-bit directive that specifies either
3155 // a splat operation or a rotation.
3156 static DecodeStatus DecodeT2SOImm(llvm::MCInst &Inst, unsigned Val,
3157                           uint64_t Address, const void *Decoder) {
3158   unsigned ctrl = fieldFromInstruction32(Val, 10, 2);
3159   if (ctrl == 0) {
3160     unsigned byte = fieldFromInstruction32(Val, 8, 2);
3161     unsigned imm = fieldFromInstruction32(Val, 0, 8);
3162     switch (byte) {
3163       case 0:
3164         Inst.addOperand(MCOperand::CreateImm(imm));
3165         break;
3166       case 1:
3167         Inst.addOperand(MCOperand::CreateImm((imm << 16) | imm));
3168         break;
3169       case 2:
3170         Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 8)));
3171         break;
3172       case 3:
3173         Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 16) |
3174                                              (imm << 8)  |  imm));
3175         break;
3176     }
3177   } else {
3178     unsigned unrot = fieldFromInstruction32(Val, 0, 7) | 0x80;
3179     unsigned rot = fieldFromInstruction32(Val, 7, 5);
3180     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
3181     Inst.addOperand(MCOperand::CreateImm(imm));
3182   }
3183 
3184   return MCDisassembler::Success;
3185 }
3186 
3187 static DecodeStatus
3188 DecodeThumbBCCTargetOperand(llvm::MCInst &Inst, unsigned Val,
3189                             uint64_t Address, const void *Decoder){
3190   Inst.addOperand(MCOperand::CreateImm(Val << 1));
3191   return MCDisassembler::Success;
3192 }
3193 
3194 static DecodeStatus DecodeThumbBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
3195                                        uint64_t Address, const void *Decoder){
3196   Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
3197   return MCDisassembler::Success;
3198 }
3199 
3200 static DecodeStatus DecodeMemBarrierOption(llvm::MCInst &Inst, unsigned Val,
3201                                    uint64_t Address, const void *Decoder) {
3202   switch (Val) {
3203   default:
3204     return MCDisassembler::Fail;
3205   case 0xF: // SY
3206   case 0xE: // ST
3207   case 0xB: // ISH
3208   case 0xA: // ISHST
3209   case 0x7: // NSH
3210   case 0x6: // NSHST
3211   case 0x3: // OSH
3212   case 0x2: // OSHST
3213     break;
3214   }
3215 
3216   Inst.addOperand(MCOperand::CreateImm(Val));
3217   return MCDisassembler::Success;
3218 }
3219 
3220 static DecodeStatus DecodeMSRMask(llvm::MCInst &Inst, unsigned Val,
3221                           uint64_t Address, const void *Decoder) {
3222   if (!Val) return MCDisassembler::Fail;
3223   Inst.addOperand(MCOperand::CreateImm(Val));
3224   return MCDisassembler::Success;
3225 }
3226 
3227 static DecodeStatus DecodeDoubleRegLoad(llvm::MCInst &Inst, unsigned Insn,
3228                                         uint64_t Address, const void *Decoder) {
3229   DecodeStatus S = MCDisassembler::Success;
3230 
3231   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3232   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3233   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3234 
3235   if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return MCDisassembler::Fail;
3236 
3237   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3238     return MCDisassembler::Fail;
3239   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
3240     return MCDisassembler::Fail;
3241   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3242     return MCDisassembler::Fail;
3243   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3244     return MCDisassembler::Fail;
3245 
3246   return S;
3247 }
3248 
3249 
3250 static DecodeStatus DecodeDoubleRegStore(llvm::MCInst &Inst, unsigned Insn,
3251                                          uint64_t Address, const void *Decoder){
3252   DecodeStatus S = MCDisassembler::Success;
3253 
3254   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3255   unsigned Rt = fieldFromInstruction32(Insn, 0, 4);
3256   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3257   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3258 
3259   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
3260     return MCDisassembler::Fail;
3261 
3262   if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return MCDisassembler::Fail;
3263   if (Rd == Rn || Rd == Rt || Rd == Rt+1) return MCDisassembler::Fail;
3264 
3265   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3266     return MCDisassembler::Fail;
3267   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
3268     return MCDisassembler::Fail;
3269   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3270     return MCDisassembler::Fail;
3271   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3272     return MCDisassembler::Fail;
3273 
3274   return S;
3275 }
3276 
3277 static DecodeStatus DecodeLDRPreImm(llvm::MCInst &Inst, unsigned Insn,
3278                             uint64_t Address, const void *Decoder) {
3279   DecodeStatus S = MCDisassembler::Success;
3280 
3281   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3282   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3283   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3284   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3285   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3286   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3287 
3288   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3289 
3290   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3291     return MCDisassembler::Fail;
3292   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3293     return MCDisassembler::Fail;
3294   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
3295     return MCDisassembler::Fail;
3296   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3297     return MCDisassembler::Fail;
3298 
3299   return S;
3300 }
3301 
3302 static DecodeStatus DecodeLDRPreReg(llvm::MCInst &Inst, unsigned Insn,
3303                             uint64_t Address, const void *Decoder) {
3304   DecodeStatus S = MCDisassembler::Success;
3305 
3306   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3307   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3308   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3309   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3310   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3311   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3312   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3313 
3314   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3315   if (Rm == 0xF) S = MCDisassembler::SoftFail;
3316 
3317   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3318     return MCDisassembler::Fail;
3319   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3320     return MCDisassembler::Fail;
3321   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
3322     return MCDisassembler::Fail;
3323   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3324     return MCDisassembler::Fail;
3325 
3326   return S;
3327 }
3328 
3329 
3330 static DecodeStatus DecodeSTRPreImm(llvm::MCInst &Inst, unsigned Insn,
3331                             uint64_t Address, const void *Decoder) {
3332   DecodeStatus S = MCDisassembler::Success;
3333 
3334   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3335   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3336   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3337   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3338   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3339   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3340 
3341   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3342 
3343   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3344     return MCDisassembler::Fail;
3345   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3346     return MCDisassembler::Fail;
3347   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
3348     return MCDisassembler::Fail;
3349   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3350     return MCDisassembler::Fail;
3351 
3352   return S;
3353 }
3354 
3355 static DecodeStatus DecodeSTRPreReg(llvm::MCInst &Inst, unsigned Insn,
3356                             uint64_t Address, const void *Decoder) {
3357   DecodeStatus S = MCDisassembler::Success;
3358 
3359   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3360   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3361   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3362   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3363   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3364   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3365 
3366   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3367 
3368   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3369     return MCDisassembler::Fail;
3370   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3371     return MCDisassembler::Fail;
3372   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
3373     return MCDisassembler::Fail;
3374   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3375     return MCDisassembler::Fail;
3376 
3377   return S;
3378 }
3379 
3380 static DecodeStatus DecodeVLD1LN(llvm::MCInst &Inst, unsigned Insn,
3381                          uint64_t Address, const void *Decoder) {
3382   DecodeStatus S = MCDisassembler::Success;
3383 
3384   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3385   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3386   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3387   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3388   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3389 
3390   unsigned align = 0;
3391   unsigned index = 0;
3392   switch (size) {
3393     default:
3394       return MCDisassembler::Fail;
3395     case 0:
3396       if (fieldFromInstruction32(Insn, 4, 1))
3397         return MCDisassembler::Fail; // UNDEFINED
3398       index = fieldFromInstruction32(Insn, 5, 3);
3399       break;
3400     case 1:
3401       if (fieldFromInstruction32(Insn, 5, 1))
3402         return MCDisassembler::Fail; // UNDEFINED
3403       index = fieldFromInstruction32(Insn, 6, 2);
3404       if (fieldFromInstruction32(Insn, 4, 1))
3405         align = 2;
3406       break;
3407     case 2:
3408       if (fieldFromInstruction32(Insn, 6, 1))
3409         return MCDisassembler::Fail; // UNDEFINED
3410       index = fieldFromInstruction32(Insn, 7, 1);
3411       if (fieldFromInstruction32(Insn, 4, 2) != 0)
3412         align = 4;
3413   }
3414 
3415   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3416     return MCDisassembler::Fail;
3417   if (Rm != 0xF) { // Writeback
3418     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3419       return MCDisassembler::Fail;
3420   }
3421   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3422     return MCDisassembler::Fail;
3423   Inst.addOperand(MCOperand::CreateImm(align));
3424   if (Rm != 0xF) {
3425     if (Rm != 0xD) {
3426       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3427         return MCDisassembler::Fail;
3428     } else
3429       Inst.addOperand(MCOperand::CreateReg(0));
3430   }
3431 
3432   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3433     return MCDisassembler::Fail;
3434   Inst.addOperand(MCOperand::CreateImm(index));
3435 
3436   return S;
3437 }
3438 
3439 static DecodeStatus DecodeVST1LN(llvm::MCInst &Inst, unsigned Insn,
3440                          uint64_t Address, const void *Decoder) {
3441   DecodeStatus S = MCDisassembler::Success;
3442 
3443   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3444   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3445   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3446   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3447   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3448 
3449   unsigned align = 0;
3450   unsigned index = 0;
3451   switch (size) {
3452     default:
3453       return MCDisassembler::Fail;
3454     case 0:
3455       if (fieldFromInstruction32(Insn, 4, 1))
3456         return MCDisassembler::Fail; // UNDEFINED
3457       index = fieldFromInstruction32(Insn, 5, 3);
3458       break;
3459     case 1:
3460       if (fieldFromInstruction32(Insn, 5, 1))
3461         return MCDisassembler::Fail; // UNDEFINED
3462       index = fieldFromInstruction32(Insn, 6, 2);
3463       if (fieldFromInstruction32(Insn, 4, 1))
3464         align = 2;
3465       break;
3466     case 2:
3467       if (fieldFromInstruction32(Insn, 6, 1))
3468         return MCDisassembler::Fail; // UNDEFINED
3469       index = fieldFromInstruction32(Insn, 7, 1);
3470       if (fieldFromInstruction32(Insn, 4, 2) != 0)
3471         align = 4;
3472   }
3473 
3474   if (Rm != 0xF) { // Writeback
3475     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3476     return MCDisassembler::Fail;
3477   }
3478   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3479     return MCDisassembler::Fail;
3480   Inst.addOperand(MCOperand::CreateImm(align));
3481   if (Rm != 0xF) {
3482     if (Rm != 0xD) {
3483       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3484     return MCDisassembler::Fail;
3485     } else
3486       Inst.addOperand(MCOperand::CreateReg(0));
3487   }
3488 
3489   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3490     return MCDisassembler::Fail;
3491   Inst.addOperand(MCOperand::CreateImm(index));
3492 
3493   return S;
3494 }
3495 
3496 
3497 static DecodeStatus DecodeVLD2LN(llvm::MCInst &Inst, unsigned Insn,
3498                          uint64_t Address, const void *Decoder) {
3499   DecodeStatus S = MCDisassembler::Success;
3500 
3501   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3502   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3503   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3504   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3505   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3506 
3507   unsigned align = 0;
3508   unsigned index = 0;
3509   unsigned inc = 1;
3510   switch (size) {
3511     default:
3512       return MCDisassembler::Fail;
3513     case 0:
3514       index = fieldFromInstruction32(Insn, 5, 3);
3515       if (fieldFromInstruction32(Insn, 4, 1))
3516         align = 2;
3517       break;
3518     case 1:
3519       index = fieldFromInstruction32(Insn, 6, 2);
3520       if (fieldFromInstruction32(Insn, 4, 1))
3521         align = 4;
3522       if (fieldFromInstruction32(Insn, 5, 1))
3523         inc = 2;
3524       break;
3525     case 2:
3526       if (fieldFromInstruction32(Insn, 5, 1))
3527         return MCDisassembler::Fail; // UNDEFINED
3528       index = fieldFromInstruction32(Insn, 7, 1);
3529       if (fieldFromInstruction32(Insn, 4, 1) != 0)
3530         align = 8;
3531       if (fieldFromInstruction32(Insn, 6, 1))
3532         inc = 2;
3533       break;
3534   }
3535 
3536   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3537     return MCDisassembler::Fail;
3538   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3539     return MCDisassembler::Fail;
3540   if (Rm != 0xF) { // Writeback
3541     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3542       return MCDisassembler::Fail;
3543   }
3544   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3545     return MCDisassembler::Fail;
3546   Inst.addOperand(MCOperand::CreateImm(align));
3547   if (Rm != 0xF) {
3548     if (Rm != 0xD) {
3549       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3550         return MCDisassembler::Fail;
3551     } else
3552       Inst.addOperand(MCOperand::CreateReg(0));
3553   }
3554 
3555   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3556     return MCDisassembler::Fail;
3557   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3558     return MCDisassembler::Fail;
3559   Inst.addOperand(MCOperand::CreateImm(index));
3560 
3561   return S;
3562 }
3563 
3564 static DecodeStatus DecodeVST2LN(llvm::MCInst &Inst, unsigned Insn,
3565                          uint64_t Address, const void *Decoder) {
3566   DecodeStatus S = MCDisassembler::Success;
3567 
3568   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3569   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3570   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3571   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3572   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3573 
3574   unsigned align = 0;
3575   unsigned index = 0;
3576   unsigned inc = 1;
3577   switch (size) {
3578     default:
3579       return MCDisassembler::Fail;
3580     case 0:
3581       index = fieldFromInstruction32(Insn, 5, 3);
3582       if (fieldFromInstruction32(Insn, 4, 1))
3583         align = 2;
3584       break;
3585     case 1:
3586       index = fieldFromInstruction32(Insn, 6, 2);
3587       if (fieldFromInstruction32(Insn, 4, 1))
3588         align = 4;
3589       if (fieldFromInstruction32(Insn, 5, 1))
3590         inc = 2;
3591       break;
3592     case 2:
3593       if (fieldFromInstruction32(Insn, 5, 1))
3594         return MCDisassembler::Fail; // UNDEFINED
3595       index = fieldFromInstruction32(Insn, 7, 1);
3596       if (fieldFromInstruction32(Insn, 4, 1) != 0)
3597         align = 8;
3598       if (fieldFromInstruction32(Insn, 6, 1))
3599         inc = 2;
3600       break;
3601   }
3602 
3603   if (Rm != 0xF) { // Writeback
3604     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3605       return MCDisassembler::Fail;
3606   }
3607   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3608     return MCDisassembler::Fail;
3609   Inst.addOperand(MCOperand::CreateImm(align));
3610   if (Rm != 0xF) {
3611     if (Rm != 0xD) {
3612       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3613         return MCDisassembler::Fail;
3614     } else
3615       Inst.addOperand(MCOperand::CreateReg(0));
3616   }
3617 
3618   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3619     return MCDisassembler::Fail;
3620   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3621     return MCDisassembler::Fail;
3622   Inst.addOperand(MCOperand::CreateImm(index));
3623 
3624   return S;
3625 }
3626 
3627 
3628 static DecodeStatus DecodeVLD3LN(llvm::MCInst &Inst, unsigned Insn,
3629                          uint64_t Address, const void *Decoder) {
3630   DecodeStatus S = MCDisassembler::Success;
3631 
3632   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3633   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3634   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3635   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3636   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3637 
3638   unsigned align = 0;
3639   unsigned index = 0;
3640   unsigned inc = 1;
3641   switch (size) {
3642     default:
3643       return MCDisassembler::Fail;
3644     case 0:
3645       if (fieldFromInstruction32(Insn, 4, 1))
3646         return MCDisassembler::Fail; // UNDEFINED
3647       index = fieldFromInstruction32(Insn, 5, 3);
3648       break;
3649     case 1:
3650       if (fieldFromInstruction32(Insn, 4, 1))
3651         return MCDisassembler::Fail; // UNDEFINED
3652       index = fieldFromInstruction32(Insn, 6, 2);
3653       if (fieldFromInstruction32(Insn, 5, 1))
3654         inc = 2;
3655       break;
3656     case 2:
3657       if (fieldFromInstruction32(Insn, 4, 2))
3658         return MCDisassembler::Fail; // UNDEFINED
3659       index = fieldFromInstruction32(Insn, 7, 1);
3660       if (fieldFromInstruction32(Insn, 6, 1))
3661         inc = 2;
3662       break;
3663   }
3664 
3665   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3666     return MCDisassembler::Fail;
3667   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3668     return MCDisassembler::Fail;
3669   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3670     return MCDisassembler::Fail;
3671 
3672   if (Rm != 0xF) { // Writeback
3673     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3674     return MCDisassembler::Fail;
3675   }
3676   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3677     return MCDisassembler::Fail;
3678   Inst.addOperand(MCOperand::CreateImm(align));
3679   if (Rm != 0xF) {
3680     if (Rm != 0xD) {
3681       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3682     return MCDisassembler::Fail;
3683     } else
3684       Inst.addOperand(MCOperand::CreateReg(0));
3685   }
3686 
3687   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3688     return MCDisassembler::Fail;
3689   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3690     return MCDisassembler::Fail;
3691   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3692     return MCDisassembler::Fail;
3693   Inst.addOperand(MCOperand::CreateImm(index));
3694 
3695   return S;
3696 }
3697 
3698 static DecodeStatus DecodeVST3LN(llvm::MCInst &Inst, unsigned Insn,
3699                          uint64_t Address, const void *Decoder) {
3700   DecodeStatus S = MCDisassembler::Success;
3701 
3702   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3703   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3704   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3705   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3706   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3707 
3708   unsigned align = 0;
3709   unsigned index = 0;
3710   unsigned inc = 1;
3711   switch (size) {
3712     default:
3713       return MCDisassembler::Fail;
3714     case 0:
3715       if (fieldFromInstruction32(Insn, 4, 1))
3716         return MCDisassembler::Fail; // UNDEFINED
3717       index = fieldFromInstruction32(Insn, 5, 3);
3718       break;
3719     case 1:
3720       if (fieldFromInstruction32(Insn, 4, 1))
3721         return MCDisassembler::Fail; // UNDEFINED
3722       index = fieldFromInstruction32(Insn, 6, 2);
3723       if (fieldFromInstruction32(Insn, 5, 1))
3724         inc = 2;
3725       break;
3726     case 2:
3727       if (fieldFromInstruction32(Insn, 4, 2))
3728         return MCDisassembler::Fail; // UNDEFINED
3729       index = fieldFromInstruction32(Insn, 7, 1);
3730       if (fieldFromInstruction32(Insn, 6, 1))
3731         inc = 2;
3732       break;
3733   }
3734 
3735   if (Rm != 0xF) { // Writeback
3736     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3737     return MCDisassembler::Fail;
3738   }
3739   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3740     return MCDisassembler::Fail;
3741   Inst.addOperand(MCOperand::CreateImm(align));
3742   if (Rm != 0xF) {
3743     if (Rm != 0xD) {
3744       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3745     return MCDisassembler::Fail;
3746     } else
3747       Inst.addOperand(MCOperand::CreateReg(0));
3748   }
3749 
3750   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3751     return MCDisassembler::Fail;
3752   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3753     return MCDisassembler::Fail;
3754   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3755     return MCDisassembler::Fail;
3756   Inst.addOperand(MCOperand::CreateImm(index));
3757 
3758   return S;
3759 }
3760 
3761 
3762 static DecodeStatus DecodeVLD4LN(llvm::MCInst &Inst, unsigned Insn,
3763                          uint64_t Address, const void *Decoder) {
3764   DecodeStatus S = MCDisassembler::Success;
3765 
3766   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3767   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3768   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3769   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3770   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3771 
3772   unsigned align = 0;
3773   unsigned index = 0;
3774   unsigned inc = 1;
3775   switch (size) {
3776     default:
3777       return MCDisassembler::Fail;
3778     case 0:
3779       if (fieldFromInstruction32(Insn, 4, 1))
3780         align = 4;
3781       index = fieldFromInstruction32(Insn, 5, 3);
3782       break;
3783     case 1:
3784       if (fieldFromInstruction32(Insn, 4, 1))
3785         align = 8;
3786       index = fieldFromInstruction32(Insn, 6, 2);
3787       if (fieldFromInstruction32(Insn, 5, 1))
3788         inc = 2;
3789       break;
3790     case 2:
3791       if (fieldFromInstruction32(Insn, 4, 2))
3792         align = 4 << fieldFromInstruction32(Insn, 4, 2);
3793       index = fieldFromInstruction32(Insn, 7, 1);
3794       if (fieldFromInstruction32(Insn, 6, 1))
3795         inc = 2;
3796       break;
3797   }
3798 
3799   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3800     return MCDisassembler::Fail;
3801   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3802     return MCDisassembler::Fail;
3803   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3804     return MCDisassembler::Fail;
3805   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
3806     return MCDisassembler::Fail;
3807 
3808   if (Rm != 0xF) { // Writeback
3809     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3810       return MCDisassembler::Fail;
3811   }
3812   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3813     return MCDisassembler::Fail;
3814   Inst.addOperand(MCOperand::CreateImm(align));
3815   if (Rm != 0xF) {
3816     if (Rm != 0xD) {
3817       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3818         return MCDisassembler::Fail;
3819     } else
3820       Inst.addOperand(MCOperand::CreateReg(0));
3821   }
3822 
3823   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3824     return MCDisassembler::Fail;
3825   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3826     return MCDisassembler::Fail;
3827   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3828     return MCDisassembler::Fail;
3829   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
3830     return MCDisassembler::Fail;
3831   Inst.addOperand(MCOperand::CreateImm(index));
3832 
3833   return S;
3834 }
3835 
3836 static DecodeStatus DecodeVST4LN(llvm::MCInst &Inst, unsigned Insn,
3837                          uint64_t Address, const void *Decoder) {
3838   DecodeStatus S = MCDisassembler::Success;
3839 
3840   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3841   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3842   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3843   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3844   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3845 
3846   unsigned align = 0;
3847   unsigned index = 0;
3848   unsigned inc = 1;
3849   switch (size) {
3850     default:
3851       return MCDisassembler::Fail;
3852     case 0:
3853       if (fieldFromInstruction32(Insn, 4, 1))
3854         align = 4;
3855       index = fieldFromInstruction32(Insn, 5, 3);
3856       break;
3857     case 1:
3858       if (fieldFromInstruction32(Insn, 4, 1))
3859         align = 8;
3860       index = fieldFromInstruction32(Insn, 6, 2);
3861       if (fieldFromInstruction32(Insn, 5, 1))
3862         inc = 2;
3863       break;
3864     case 2:
3865       if (fieldFromInstruction32(Insn, 4, 2))
3866         align = 4 << fieldFromInstruction32(Insn, 4, 2);
3867       index = fieldFromInstruction32(Insn, 7, 1);
3868       if (fieldFromInstruction32(Insn, 6, 1))
3869         inc = 2;
3870       break;
3871   }
3872 
3873   if (Rm != 0xF) { // Writeback
3874     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3875     return MCDisassembler::Fail;
3876   }
3877   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3878     return MCDisassembler::Fail;
3879   Inst.addOperand(MCOperand::CreateImm(align));
3880   if (Rm != 0xF) {
3881     if (Rm != 0xD) {
3882       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3883     return MCDisassembler::Fail;
3884     } else
3885       Inst.addOperand(MCOperand::CreateReg(0));
3886   }
3887 
3888   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3889     return MCDisassembler::Fail;
3890   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3891     return MCDisassembler::Fail;
3892   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3893     return MCDisassembler::Fail;
3894   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
3895     return MCDisassembler::Fail;
3896   Inst.addOperand(MCOperand::CreateImm(index));
3897 
3898   return S;
3899 }
3900 
3901 static DecodeStatus DecodeVMOVSRR(llvm::MCInst &Inst, unsigned Insn,
3902                                   uint64_t Address, const void *Decoder) {
3903   DecodeStatus S = MCDisassembler::Success;
3904   unsigned Rt  = fieldFromInstruction32(Insn, 12, 4);
3905   unsigned Rt2 = fieldFromInstruction32(Insn, 16, 4);
3906   unsigned Rm  = fieldFromInstruction32(Insn,  0, 4);
3907   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3908   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
3909 
3910   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
3911     S = MCDisassembler::SoftFail;
3912 
3913   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
3914     return MCDisassembler::Fail;
3915   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
3916     return MCDisassembler::Fail;
3917   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
3918     return MCDisassembler::Fail;
3919   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
3920     return MCDisassembler::Fail;
3921   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3922     return MCDisassembler::Fail;
3923 
3924   return S;
3925 }
3926 
3927 static DecodeStatus DecodeVMOVRRS(llvm::MCInst &Inst, unsigned Insn,
3928                                   uint64_t Address, const void *Decoder) {
3929   DecodeStatus S = MCDisassembler::Success;
3930   unsigned Rt  = fieldFromInstruction32(Insn, 12, 4);
3931   unsigned Rt2 = fieldFromInstruction32(Insn, 16, 4);
3932   unsigned Rm  = fieldFromInstruction32(Insn,  0, 4);
3933   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3934   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
3935 
3936   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
3937     S = MCDisassembler::SoftFail;
3938 
3939   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
3940     return MCDisassembler::Fail;
3941   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
3942     return MCDisassembler::Fail;
3943   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
3944     return MCDisassembler::Fail;
3945   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
3946     return MCDisassembler::Fail;
3947   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3948     return MCDisassembler::Fail;
3949 
3950   return S;
3951 }
3952 
3953 static DecodeStatus DecodeIT(llvm::MCInst &Inst, unsigned Insn,
3954                              uint64_t Address, const void *Decoder) {
3955   DecodeStatus S = MCDisassembler::Success;
3956   unsigned pred = fieldFromInstruction16(Insn, 4, 4);
3957   // The InstPrinter needs to have the low bit of the predicate in
3958   // the mask operand to be able to print it properly.
3959   unsigned mask = fieldFromInstruction16(Insn, 0, 5);
3960 
3961   if (pred == 0xF) {
3962     pred = 0xE;
3963     S = MCDisassembler::SoftFail;
3964   }
3965 
3966   if ((mask & 0xF) == 0) {
3967     // Preserve the high bit of the mask, which is the low bit of
3968     // the predicate.
3969     mask &= 0x10;
3970     mask |= 0x8;
3971     S = MCDisassembler::SoftFail;
3972   }
3973 
3974   Inst.addOperand(MCOperand::CreateImm(pred));
3975   Inst.addOperand(MCOperand::CreateImm(mask));
3976   return S;
3977 }
3978 
3979 static DecodeStatus
3980 DecodeT2LDRDPreInstruction(llvm::MCInst &Inst, unsigned Insn,
3981                            uint64_t Address, const void *Decoder) {
3982   DecodeStatus S = MCDisassembler::Success;
3983 
3984   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3985   unsigned Rt2 = fieldFromInstruction32(Insn, 8, 4);
3986   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3987   unsigned addr = fieldFromInstruction32(Insn, 0, 8);
3988   unsigned W = fieldFromInstruction32(Insn, 21, 1);
3989   unsigned U = fieldFromInstruction32(Insn, 23, 1);
3990   unsigned P = fieldFromInstruction32(Insn, 24, 1);
3991   bool writeback = (W == 1) | (P == 0);
3992 
3993   addr |= (U << 8) | (Rn << 9);
3994 
3995   if (writeback && (Rn == Rt || Rn == Rt2))
3996     Check(S, MCDisassembler::SoftFail);
3997   if (Rt == Rt2)
3998     Check(S, MCDisassembler::SoftFail);
3999 
4000   // Rt
4001   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
4002     return MCDisassembler::Fail;
4003   // Rt2
4004   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
4005     return MCDisassembler::Fail;
4006   // Writeback operand
4007   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
4008     return MCDisassembler::Fail;
4009   // addr
4010   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
4011     return MCDisassembler::Fail;
4012 
4013   return S;
4014 }
4015 
4016 static DecodeStatus
4017 DecodeT2STRDPreInstruction(llvm::MCInst &Inst, unsigned Insn,
4018                            uint64_t Address, const void *Decoder) {
4019   DecodeStatus S = MCDisassembler::Success;
4020 
4021   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
4022   unsigned Rt2 = fieldFromInstruction32(Insn, 8, 4);
4023   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
4024   unsigned addr = fieldFromInstruction32(Insn, 0, 8);
4025   unsigned W = fieldFromInstruction32(Insn, 21, 1);
4026   unsigned U = fieldFromInstruction32(Insn, 23, 1);
4027   unsigned P = fieldFromInstruction32(Insn, 24, 1);
4028   bool writeback = (W == 1) | (P == 0);
4029 
4030   addr |= (U << 8) | (Rn << 9);
4031 
4032   if (writeback && (Rn == Rt || Rn == Rt2))
4033     Check(S, MCDisassembler::SoftFail);
4034 
4035   // Writeback operand
4036   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
4037     return MCDisassembler::Fail;
4038   // Rt
4039   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
4040     return MCDisassembler::Fail;
4041   // Rt2
4042   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
4043     return MCDisassembler::Fail;
4044   // addr
4045   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
4046     return MCDisassembler::Fail;
4047 
4048   return S;
4049 }
4050 
4051 static DecodeStatus DecodeT2Adr(llvm::MCInst &Inst, uint32_t Insn,
4052                                 uint64_t Address, const void *Decoder) {
4053   unsigned sign1 = fieldFromInstruction32(Insn, 21, 1);
4054   unsigned sign2 = fieldFromInstruction32(Insn, 23, 1);
4055   if (sign1 != sign2) return MCDisassembler::Fail;
4056 
4057   unsigned Val = fieldFromInstruction32(Insn, 0, 8);
4058   Val |= fieldFromInstruction32(Insn, 12, 3) << 8;
4059   Val |= fieldFromInstruction32(Insn, 26, 1) << 11;
4060   Val |= sign1 << 12;
4061   Inst.addOperand(MCOperand::CreateImm(SignExtend32<13>(Val)));
4062 
4063   return MCDisassembler::Success;
4064 }
4065 
4066 static DecodeStatus DecodeT2ShifterImmOperand(llvm::MCInst &Inst, uint32_t Val,
4067                                               uint64_t Address,
4068                                               const void *Decoder) {
4069   DecodeStatus S = MCDisassembler::Success;
4070 
4071   // Shift of "asr #32" is not allowed in Thumb2 mode.
4072   if (Val == 0x20) S = MCDisassembler::SoftFail;
4073   Inst.addOperand(MCOperand::CreateImm(Val));
4074   return S;
4075 }
4076 
4077