xref: /llvm-project/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (revision 5dcda643383fe718f7dc91be090f76269559fe86)
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     Check(result, AddThumbPredicate(MI));
728 
729     // If we find an IT instruction, we need to parse its condition
730     // code and mask operands so that we can apply them correctly
731     // to the subsequent instructions.
732     if (MI.getOpcode() == ARM::t2IT) {
733       // Nested IT blocks are UNPREDICTABLE.
734       if (!ITBlock.empty())
735         return MCDisassembler::SoftFail;
736 
737       // (3 - the number of trailing zeros) is the number of then / else.
738       unsigned firstcond = MI.getOperand(0).getImm();
739       unsigned Mask = MI.getOperand(1).getImm();
740       unsigned CondBit0 = Mask >> 4 & 1;
741       unsigned NumTZ = CountTrailingZeros_32(Mask);
742       assert(NumTZ <= 3 && "Invalid IT mask!");
743       for (unsigned Pos = 3, e = NumTZ; Pos > e; --Pos) {
744         bool T = ((Mask >> Pos) & 1) == CondBit0;
745         if (T)
746           ITBlock.insert(ITBlock.begin(), firstcond);
747         else
748           ITBlock.insert(ITBlock.begin(), firstcond ^ 1);
749       }
750 
751       ITBlock.push_back(firstcond);
752     }
753 
754     return result;
755   }
756 
757   // We want to read exactly 4 bytes of data.
758   if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1) {
759     Size = 0;
760     return MCDisassembler::Fail;
761   }
762 
763   uint32_t insn32 = (bytes[3] <<  8) |
764                     (bytes[2] <<  0) |
765                     (bytes[1] << 24) |
766                     (bytes[0] << 16);
767   MI.clear();
768   result = decodeThumbInstruction32(MI, insn32, Address, this, STI);
769   if (result != MCDisassembler::Fail) {
770     Size = 4;
771     bool InITBlock = ITBlock.size();
772     Check(result, AddThumbPredicate(MI));
773     AddThumb1SBit(MI, InITBlock);
774     return result;
775   }
776 
777   MI.clear();
778   result = decodeThumb2Instruction32(MI, insn32, Address, this, STI);
779   if (result != MCDisassembler::Fail) {
780     Size = 4;
781     Check(result, AddThumbPredicate(MI));
782     return result;
783   }
784 
785   MI.clear();
786   result = decodeVFPInstruction32(MI, insn32, Address, this, STI);
787   if (result != MCDisassembler::Fail) {
788     Size = 4;
789     UpdateThumbVFPPredicate(MI);
790     return result;
791   }
792 
793   MI.clear();
794   result = decodeNEONDupInstruction32(MI, insn32, Address, this, STI);
795   if (result != MCDisassembler::Fail) {
796     Size = 4;
797     Check(result, AddThumbPredicate(MI));
798     return result;
799   }
800 
801   if (fieldFromInstruction32(insn32, 24, 8) == 0xF9) {
802     MI.clear();
803     uint32_t NEONLdStInsn = insn32;
804     NEONLdStInsn &= 0xF0FFFFFF;
805     NEONLdStInsn |= 0x04000000;
806     result = decodeNEONLoadStoreInstruction32(MI, NEONLdStInsn, Address, this, STI);
807     if (result != MCDisassembler::Fail) {
808       Size = 4;
809       Check(result, AddThumbPredicate(MI));
810       return result;
811     }
812   }
813 
814   if (fieldFromInstruction32(insn32, 24, 4) == 0xF) {
815     MI.clear();
816     uint32_t NEONDataInsn = insn32;
817     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
818     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
819     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
820     result = decodeNEONDataInstruction32(MI, NEONDataInsn, Address, this, STI);
821     if (result != MCDisassembler::Fail) {
822       Size = 4;
823       Check(result, AddThumbPredicate(MI));
824       return result;
825     }
826   }
827 
828   Size = 0;
829   return MCDisassembler::Fail;
830 }
831 
832 
833 extern "C" void LLVMInitializeARMDisassembler() {
834   TargetRegistry::RegisterMCDisassembler(TheARMTarget,
835                                          createARMDisassembler);
836   TargetRegistry::RegisterMCDisassembler(TheThumbTarget,
837                                          createThumbDisassembler);
838 }
839 
840 static const unsigned GPRDecoderTable[] = {
841   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
842   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
843   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
844   ARM::R12, ARM::SP, ARM::LR, ARM::PC
845 };
846 
847 static DecodeStatus DecodeGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
848                                    uint64_t Address, const void *Decoder) {
849   if (RegNo > 15)
850     return MCDisassembler::Fail;
851 
852   unsigned Register = GPRDecoderTable[RegNo];
853   Inst.addOperand(MCOperand::CreateReg(Register));
854   return MCDisassembler::Success;
855 }
856 
857 static DecodeStatus
858 DecodeGPRnopcRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
859                            uint64_t Address, const void *Decoder) {
860   if (RegNo == 15) return MCDisassembler::Fail;
861   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
862 }
863 
864 static DecodeStatus DecodetGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
865                                    uint64_t Address, const void *Decoder) {
866   if (RegNo > 7)
867     return MCDisassembler::Fail;
868   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
869 }
870 
871 static DecodeStatus DecodetcGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
872                                    uint64_t Address, const void *Decoder) {
873   unsigned Register = 0;
874   switch (RegNo) {
875     case 0:
876       Register = ARM::R0;
877       break;
878     case 1:
879       Register = ARM::R1;
880       break;
881     case 2:
882       Register = ARM::R2;
883       break;
884     case 3:
885       Register = ARM::R3;
886       break;
887     case 9:
888       Register = ARM::R9;
889       break;
890     case 12:
891       Register = ARM::R12;
892       break;
893     default:
894       return MCDisassembler::Fail;
895     }
896 
897   Inst.addOperand(MCOperand::CreateReg(Register));
898   return MCDisassembler::Success;
899 }
900 
901 static DecodeStatus DecoderGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
902                                    uint64_t Address, const void *Decoder) {
903   if (RegNo == 13 || RegNo == 15) return MCDisassembler::Fail;
904   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
905 }
906 
907 static const unsigned SPRDecoderTable[] = {
908      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
909      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
910      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
911     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
912     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
913     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
914     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
915     ARM::S28, ARM::S29, ARM::S30, ARM::S31
916 };
917 
918 static DecodeStatus DecodeSPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
919                                    uint64_t Address, const void *Decoder) {
920   if (RegNo > 31)
921     return MCDisassembler::Fail;
922 
923   unsigned Register = SPRDecoderTable[RegNo];
924   Inst.addOperand(MCOperand::CreateReg(Register));
925   return MCDisassembler::Success;
926 }
927 
928 static const unsigned DPRDecoderTable[] = {
929      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
930      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
931      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
932     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
933     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
934     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
935     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
936     ARM::D28, ARM::D29, ARM::D30, ARM::D31
937 };
938 
939 static DecodeStatus DecodeDPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
940                                    uint64_t Address, const void *Decoder) {
941   if (RegNo > 31)
942     return MCDisassembler::Fail;
943 
944   unsigned Register = DPRDecoderTable[RegNo];
945   Inst.addOperand(MCOperand::CreateReg(Register));
946   return MCDisassembler::Success;
947 }
948 
949 static DecodeStatus DecodeDPR_8RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
950                                    uint64_t Address, const void *Decoder) {
951   if (RegNo > 7)
952     return MCDisassembler::Fail;
953   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
954 }
955 
956 static DecodeStatus
957 DecodeDPR_VFP2RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
958                             uint64_t Address, const void *Decoder) {
959   if (RegNo > 15)
960     return MCDisassembler::Fail;
961   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
962 }
963 
964 static const unsigned QPRDecoderTable[] = {
965      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
966      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
967      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
968     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
969 };
970 
971 
972 static DecodeStatus DecodeQPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
973                                    uint64_t Address, const void *Decoder) {
974   if (RegNo > 31)
975     return MCDisassembler::Fail;
976   RegNo >>= 1;
977 
978   unsigned Register = QPRDecoderTable[RegNo];
979   Inst.addOperand(MCOperand::CreateReg(Register));
980   return MCDisassembler::Success;
981 }
982 
983 static DecodeStatus DecodePredicateOperand(llvm::MCInst &Inst, unsigned Val,
984                                uint64_t Address, const void *Decoder) {
985   if (Val == 0xF) return MCDisassembler::Fail;
986   // AL predicate is not allowed on Thumb1 branches.
987   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
988     return MCDisassembler::Fail;
989   Inst.addOperand(MCOperand::CreateImm(Val));
990   if (Val == ARMCC::AL) {
991     Inst.addOperand(MCOperand::CreateReg(0));
992   } else
993     Inst.addOperand(MCOperand::CreateReg(ARM::CPSR));
994   return MCDisassembler::Success;
995 }
996 
997 static DecodeStatus DecodeCCOutOperand(llvm::MCInst &Inst, unsigned Val,
998                                uint64_t Address, const void *Decoder) {
999   if (Val)
1000     Inst.addOperand(MCOperand::CreateReg(ARM::CPSR));
1001   else
1002     Inst.addOperand(MCOperand::CreateReg(0));
1003   return MCDisassembler::Success;
1004 }
1005 
1006 static DecodeStatus DecodeSOImmOperand(llvm::MCInst &Inst, unsigned Val,
1007                                uint64_t Address, const void *Decoder) {
1008   uint32_t imm = Val & 0xFF;
1009   uint32_t rot = (Val & 0xF00) >> 7;
1010   uint32_t rot_imm = (imm >> rot) | (imm << (32-rot));
1011   Inst.addOperand(MCOperand::CreateImm(rot_imm));
1012   return MCDisassembler::Success;
1013 }
1014 
1015 static DecodeStatus DecodeSORegImmOperand(llvm::MCInst &Inst, unsigned Val,
1016                                uint64_t Address, const void *Decoder) {
1017   DecodeStatus S = MCDisassembler::Success;
1018 
1019   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
1020   unsigned type = fieldFromInstruction32(Val, 5, 2);
1021   unsigned imm = fieldFromInstruction32(Val, 7, 5);
1022 
1023   // Register-immediate
1024   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1025     return MCDisassembler::Fail;
1026 
1027   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1028   switch (type) {
1029     case 0:
1030       Shift = ARM_AM::lsl;
1031       break;
1032     case 1:
1033       Shift = ARM_AM::lsr;
1034       break;
1035     case 2:
1036       Shift = ARM_AM::asr;
1037       break;
1038     case 3:
1039       Shift = ARM_AM::ror;
1040       break;
1041   }
1042 
1043   if (Shift == ARM_AM::ror && imm == 0)
1044     Shift = ARM_AM::rrx;
1045 
1046   unsigned Op = Shift | (imm << 3);
1047   Inst.addOperand(MCOperand::CreateImm(Op));
1048 
1049   return S;
1050 }
1051 
1052 static DecodeStatus DecodeSORegRegOperand(llvm::MCInst &Inst, unsigned Val,
1053                                uint64_t Address, const void *Decoder) {
1054   DecodeStatus S = MCDisassembler::Success;
1055 
1056   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
1057   unsigned type = fieldFromInstruction32(Val, 5, 2);
1058   unsigned Rs = fieldFromInstruction32(Val, 8, 4);
1059 
1060   // Register-register
1061   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1062     return MCDisassembler::Fail;
1063   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1064     return MCDisassembler::Fail;
1065 
1066   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1067   switch (type) {
1068     case 0:
1069       Shift = ARM_AM::lsl;
1070       break;
1071     case 1:
1072       Shift = ARM_AM::lsr;
1073       break;
1074     case 2:
1075       Shift = ARM_AM::asr;
1076       break;
1077     case 3:
1078       Shift = ARM_AM::ror;
1079       break;
1080   }
1081 
1082   Inst.addOperand(MCOperand::CreateImm(Shift));
1083 
1084   return S;
1085 }
1086 
1087 static DecodeStatus DecodeRegListOperand(llvm::MCInst &Inst, unsigned Val,
1088                                  uint64_t Address, const void *Decoder) {
1089   DecodeStatus S = MCDisassembler::Success;
1090 
1091   bool writebackLoad = false;
1092   unsigned writebackReg = 0;
1093   switch (Inst.getOpcode()) {
1094     default:
1095       break;
1096     case ARM::LDMIA_UPD:
1097     case ARM::LDMDB_UPD:
1098     case ARM::LDMIB_UPD:
1099     case ARM::LDMDA_UPD:
1100     case ARM::t2LDMIA_UPD:
1101     case ARM::t2LDMDB_UPD:
1102       writebackLoad = true;
1103       writebackReg = Inst.getOperand(0).getReg();
1104       break;
1105   }
1106 
1107   // Empty register lists are not allowed.
1108   if (CountPopulation_32(Val) == 0) return MCDisassembler::Fail;
1109   for (unsigned i = 0; i < 16; ++i) {
1110     if (Val & (1 << i)) {
1111       if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1112         return MCDisassembler::Fail;
1113       // Writeback not allowed if Rn is in the target list.
1114       if (writebackLoad && writebackReg == Inst.end()[-1].getReg())
1115         Check(S, MCDisassembler::SoftFail);
1116     }
1117   }
1118 
1119   return S;
1120 }
1121 
1122 static DecodeStatus DecodeSPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
1123                                  uint64_t Address, const void *Decoder) {
1124   DecodeStatus S = MCDisassembler::Success;
1125 
1126   unsigned Vd = fieldFromInstruction32(Val, 8, 4);
1127   unsigned regs = Val & 0xFF;
1128 
1129   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1130     return MCDisassembler::Fail;
1131   for (unsigned i = 0; i < (regs - 1); ++i) {
1132     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1133       return MCDisassembler::Fail;
1134   }
1135 
1136   return S;
1137 }
1138 
1139 static DecodeStatus DecodeDPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
1140                                  uint64_t Address, const void *Decoder) {
1141   DecodeStatus S = MCDisassembler::Success;
1142 
1143   unsigned Vd = fieldFromInstruction32(Val, 8, 4);
1144   unsigned regs = (Val & 0xFF) / 2;
1145 
1146   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1147       return MCDisassembler::Fail;
1148   for (unsigned i = 0; i < (regs - 1); ++i) {
1149     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1150       return MCDisassembler::Fail;
1151   }
1152 
1153   return S;
1154 }
1155 
1156 static DecodeStatus DecodeBitfieldMaskOperand(llvm::MCInst &Inst, unsigned Val,
1157                                       uint64_t Address, const void *Decoder) {
1158   // This operand encodes a mask of contiguous zeros between a specified MSB
1159   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1160   // the mask of all bits LSB-and-lower, and then xor them to create
1161   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1162   // create the final mask.
1163   unsigned msb = fieldFromInstruction32(Val, 5, 5);
1164   unsigned lsb = fieldFromInstruction32(Val, 0, 5);
1165 
1166   DecodeStatus S = MCDisassembler::Success;
1167   if (lsb > msb) Check(S, MCDisassembler::SoftFail);
1168 
1169   uint32_t msb_mask = 0xFFFFFFFF;
1170   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1171   uint32_t lsb_mask = (1U << lsb) - 1;
1172 
1173   Inst.addOperand(MCOperand::CreateImm(~(msb_mask ^ lsb_mask)));
1174   return S;
1175 }
1176 
1177 static DecodeStatus DecodeCopMemInstruction(llvm::MCInst &Inst, unsigned Insn,
1178                                   uint64_t Address, const void *Decoder) {
1179   DecodeStatus S = MCDisassembler::Success;
1180 
1181   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1182   unsigned CRd = fieldFromInstruction32(Insn, 12, 4);
1183   unsigned coproc = fieldFromInstruction32(Insn, 8, 4);
1184   unsigned imm = fieldFromInstruction32(Insn, 0, 8);
1185   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1186   unsigned U = fieldFromInstruction32(Insn, 23, 1);
1187 
1188   switch (Inst.getOpcode()) {
1189     case ARM::LDC_OFFSET:
1190     case ARM::LDC_PRE:
1191     case ARM::LDC_POST:
1192     case ARM::LDC_OPTION:
1193     case ARM::LDCL_OFFSET:
1194     case ARM::LDCL_PRE:
1195     case ARM::LDCL_POST:
1196     case ARM::LDCL_OPTION:
1197     case ARM::STC_OFFSET:
1198     case ARM::STC_PRE:
1199     case ARM::STC_POST:
1200     case ARM::STC_OPTION:
1201     case ARM::STCL_OFFSET:
1202     case ARM::STCL_PRE:
1203     case ARM::STCL_POST:
1204     case ARM::STCL_OPTION:
1205     case ARM::t2LDC_OFFSET:
1206     case ARM::t2LDC_PRE:
1207     case ARM::t2LDC_POST:
1208     case ARM::t2LDC_OPTION:
1209     case ARM::t2LDCL_OFFSET:
1210     case ARM::t2LDCL_PRE:
1211     case ARM::t2LDCL_POST:
1212     case ARM::t2LDCL_OPTION:
1213     case ARM::t2STC_OFFSET:
1214     case ARM::t2STC_PRE:
1215     case ARM::t2STC_POST:
1216     case ARM::t2STC_OPTION:
1217     case ARM::t2STCL_OFFSET:
1218     case ARM::t2STCL_PRE:
1219     case ARM::t2STCL_POST:
1220     case ARM::t2STCL_OPTION:
1221       if (coproc == 0xA || coproc == 0xB)
1222         return MCDisassembler::Fail;
1223       break;
1224     default:
1225       break;
1226   }
1227 
1228   Inst.addOperand(MCOperand::CreateImm(coproc));
1229   Inst.addOperand(MCOperand::CreateImm(CRd));
1230   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1231     return MCDisassembler::Fail;
1232   switch (Inst.getOpcode()) {
1233     case ARM::LDC_OPTION:
1234     case ARM::LDCL_OPTION:
1235     case ARM::LDC2_OPTION:
1236     case ARM::LDC2L_OPTION:
1237     case ARM::STC_OPTION:
1238     case ARM::STCL_OPTION:
1239     case ARM::STC2_OPTION:
1240     case ARM::STC2L_OPTION:
1241     case ARM::LDCL_POST:
1242     case ARM::STCL_POST:
1243     case ARM::LDC2L_POST:
1244     case ARM::STC2L_POST:
1245     case ARM::t2LDC_OPTION:
1246     case ARM::t2LDCL_OPTION:
1247     case ARM::t2STC_OPTION:
1248     case ARM::t2STCL_OPTION:
1249     case ARM::t2LDCL_POST:
1250     case ARM::t2STCL_POST:
1251       break;
1252     default:
1253       Inst.addOperand(MCOperand::CreateReg(0));
1254       break;
1255   }
1256 
1257   unsigned P = fieldFromInstruction32(Insn, 24, 1);
1258   unsigned W = fieldFromInstruction32(Insn, 21, 1);
1259 
1260   bool writeback = (P == 0) || (W == 1);
1261   unsigned idx_mode = 0;
1262   if (P && writeback)
1263     idx_mode = ARMII::IndexModePre;
1264   else if (!P && writeback)
1265     idx_mode = ARMII::IndexModePost;
1266 
1267   switch (Inst.getOpcode()) {
1268     case ARM::LDCL_POST:
1269     case ARM::STCL_POST:
1270     case ARM::t2LDCL_POST:
1271     case ARM::t2STCL_POST:
1272     case ARM::LDC2L_POST:
1273     case ARM::STC2L_POST:
1274       imm |= U << 8;
1275     case ARM::LDC_OPTION:
1276     case ARM::LDCL_OPTION:
1277     case ARM::LDC2_OPTION:
1278     case ARM::LDC2L_OPTION:
1279     case ARM::STC_OPTION:
1280     case ARM::STCL_OPTION:
1281     case ARM::STC2_OPTION:
1282     case ARM::STC2L_OPTION:
1283     case ARM::t2LDC_OPTION:
1284     case ARM::t2LDCL_OPTION:
1285     case ARM::t2STC_OPTION:
1286     case ARM::t2STCL_OPTION:
1287       Inst.addOperand(MCOperand::CreateImm(imm));
1288       break;
1289     default:
1290       if (U)
1291         Inst.addOperand(MCOperand::CreateImm(
1292             ARM_AM::getAM2Opc(ARM_AM::add, imm, ARM_AM::lsl, idx_mode)));
1293       else
1294         Inst.addOperand(MCOperand::CreateImm(
1295             ARM_AM::getAM2Opc(ARM_AM::sub, imm, ARM_AM::lsl, idx_mode)));
1296       break;
1297   }
1298 
1299   switch (Inst.getOpcode()) {
1300     case ARM::LDC_OFFSET:
1301     case ARM::LDC_PRE:
1302     case ARM::LDC_POST:
1303     case ARM::LDC_OPTION:
1304     case ARM::LDCL_OFFSET:
1305     case ARM::LDCL_PRE:
1306     case ARM::LDCL_POST:
1307     case ARM::LDCL_OPTION:
1308     case ARM::STC_OFFSET:
1309     case ARM::STC_PRE:
1310     case ARM::STC_POST:
1311     case ARM::STC_OPTION:
1312     case ARM::STCL_OFFSET:
1313     case ARM::STCL_PRE:
1314     case ARM::STCL_POST:
1315     case ARM::STCL_OPTION:
1316       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1317         return MCDisassembler::Fail;
1318       break;
1319     default:
1320       break;
1321   }
1322 
1323   return S;
1324 }
1325 
1326 static DecodeStatus
1327 DecodeAddrMode2IdxInstruction(llvm::MCInst &Inst, unsigned Insn,
1328                               uint64_t Address, const void *Decoder) {
1329   DecodeStatus S = MCDisassembler::Success;
1330 
1331   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1332   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
1333   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1334   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
1335   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1336   unsigned reg = fieldFromInstruction32(Insn, 25, 1);
1337   unsigned P = fieldFromInstruction32(Insn, 24, 1);
1338   unsigned W = fieldFromInstruction32(Insn, 21, 1);
1339 
1340   // On stores, the writeback operand precedes Rt.
1341   switch (Inst.getOpcode()) {
1342     case ARM::STR_POST_IMM:
1343     case ARM::STR_POST_REG:
1344     case ARM::STRB_POST_IMM:
1345     case ARM::STRB_POST_REG:
1346     case ARM::STRT_POST_REG:
1347     case ARM::STRT_POST_IMM:
1348     case ARM::STRBT_POST_REG:
1349     case ARM::STRBT_POST_IMM:
1350       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1351         return MCDisassembler::Fail;
1352       break;
1353     default:
1354       break;
1355   }
1356 
1357   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1358     return MCDisassembler::Fail;
1359 
1360   // On loads, the writeback operand comes after Rt.
1361   switch (Inst.getOpcode()) {
1362     case ARM::LDR_POST_IMM:
1363     case ARM::LDR_POST_REG:
1364     case ARM::LDRB_POST_IMM:
1365     case ARM::LDRB_POST_REG:
1366     case ARM::LDRBT_POST_REG:
1367     case ARM::LDRBT_POST_IMM:
1368     case ARM::LDRT_POST_REG:
1369     case ARM::LDRT_POST_IMM:
1370       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1371         return MCDisassembler::Fail;
1372       break;
1373     default:
1374       break;
1375   }
1376 
1377   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1378     return MCDisassembler::Fail;
1379 
1380   ARM_AM::AddrOpc Op = ARM_AM::add;
1381   if (!fieldFromInstruction32(Insn, 23, 1))
1382     Op = ARM_AM::sub;
1383 
1384   bool writeback = (P == 0) || (W == 1);
1385   unsigned idx_mode = 0;
1386   if (P && writeback)
1387     idx_mode = ARMII::IndexModePre;
1388   else if (!P && writeback)
1389     idx_mode = ARMII::IndexModePost;
1390 
1391   if (writeback && (Rn == 15 || Rn == Rt))
1392     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1393 
1394   if (reg) {
1395     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1396       return MCDisassembler::Fail;
1397     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1398     switch( fieldFromInstruction32(Insn, 5, 2)) {
1399       case 0:
1400         Opc = ARM_AM::lsl;
1401         break;
1402       case 1:
1403         Opc = ARM_AM::lsr;
1404         break;
1405       case 2:
1406         Opc = ARM_AM::asr;
1407         break;
1408       case 3:
1409         Opc = ARM_AM::ror;
1410         break;
1411       default:
1412         return MCDisassembler::Fail;
1413     }
1414     unsigned amt = fieldFromInstruction32(Insn, 7, 5);
1415     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1416 
1417     Inst.addOperand(MCOperand::CreateImm(imm));
1418   } else {
1419     Inst.addOperand(MCOperand::CreateReg(0));
1420     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1421     Inst.addOperand(MCOperand::CreateImm(tmp));
1422   }
1423 
1424   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1425     return MCDisassembler::Fail;
1426 
1427   return S;
1428 }
1429 
1430 static DecodeStatus DecodeSORegMemOperand(llvm::MCInst &Inst, unsigned Val,
1431                                   uint64_t Address, const void *Decoder) {
1432   DecodeStatus S = MCDisassembler::Success;
1433 
1434   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
1435   unsigned Rm = fieldFromInstruction32(Val,  0, 4);
1436   unsigned type = fieldFromInstruction32(Val, 5, 2);
1437   unsigned imm = fieldFromInstruction32(Val, 7, 5);
1438   unsigned U = fieldFromInstruction32(Val, 12, 1);
1439 
1440   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1441   switch (type) {
1442     case 0:
1443       ShOp = ARM_AM::lsl;
1444       break;
1445     case 1:
1446       ShOp = ARM_AM::lsr;
1447       break;
1448     case 2:
1449       ShOp = ARM_AM::asr;
1450       break;
1451     case 3:
1452       ShOp = ARM_AM::ror;
1453       break;
1454   }
1455 
1456   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1457     return MCDisassembler::Fail;
1458   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1459     return MCDisassembler::Fail;
1460   unsigned shift;
1461   if (U)
1462     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1463   else
1464     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1465   Inst.addOperand(MCOperand::CreateImm(shift));
1466 
1467   return S;
1468 }
1469 
1470 static DecodeStatus
1471 DecodeAddrMode3Instruction(llvm::MCInst &Inst, unsigned Insn,
1472                            uint64_t Address, const void *Decoder) {
1473   DecodeStatus S = MCDisassembler::Success;
1474 
1475   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
1476   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1477   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1478   unsigned type = fieldFromInstruction32(Insn, 22, 1);
1479   unsigned imm = fieldFromInstruction32(Insn, 8, 4);
1480   unsigned U = ((~fieldFromInstruction32(Insn, 23, 1)) & 1) << 8;
1481   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1482   unsigned W = fieldFromInstruction32(Insn, 21, 1);
1483   unsigned P = fieldFromInstruction32(Insn, 24, 1);
1484 
1485   bool writeback = (W == 1) | (P == 0);
1486 
1487   // For {LD,ST}RD, Rt must be even, else undefined.
1488   switch (Inst.getOpcode()) {
1489     case ARM::STRD:
1490     case ARM::STRD_PRE:
1491     case ARM::STRD_POST:
1492     case ARM::LDRD:
1493     case ARM::LDRD_PRE:
1494     case ARM::LDRD_POST:
1495       if (Rt & 0x1) return MCDisassembler::Fail;
1496       break;
1497     default:
1498       break;
1499   }
1500 
1501   if (writeback) { // Writeback
1502     if (P)
1503       U |= ARMII::IndexModePre << 9;
1504     else
1505       U |= ARMII::IndexModePost << 9;
1506 
1507     // On stores, the writeback operand precedes Rt.
1508     switch (Inst.getOpcode()) {
1509     case ARM::STRD:
1510     case ARM::STRD_PRE:
1511     case ARM::STRD_POST:
1512     case ARM::STRH:
1513     case ARM::STRH_PRE:
1514     case ARM::STRH_POST:
1515       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1516         return MCDisassembler::Fail;
1517       break;
1518     default:
1519       break;
1520     }
1521   }
1522 
1523   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1524     return MCDisassembler::Fail;
1525   switch (Inst.getOpcode()) {
1526     case ARM::STRD:
1527     case ARM::STRD_PRE:
1528     case ARM::STRD_POST:
1529     case ARM::LDRD:
1530     case ARM::LDRD_PRE:
1531     case ARM::LDRD_POST:
1532       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
1533         return MCDisassembler::Fail;
1534       break;
1535     default:
1536       break;
1537   }
1538 
1539   if (writeback) {
1540     // On loads, the writeback operand comes after Rt.
1541     switch (Inst.getOpcode()) {
1542     case ARM::LDRD:
1543     case ARM::LDRD_PRE:
1544     case ARM::LDRD_POST:
1545     case ARM::LDRH:
1546     case ARM::LDRH_PRE:
1547     case ARM::LDRH_POST:
1548     case ARM::LDRSH:
1549     case ARM::LDRSH_PRE:
1550     case ARM::LDRSH_POST:
1551     case ARM::LDRSB:
1552     case ARM::LDRSB_PRE:
1553     case ARM::LDRSB_POST:
1554     case ARM::LDRHTr:
1555     case ARM::LDRSBTr:
1556       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1557         return MCDisassembler::Fail;
1558       break;
1559     default:
1560       break;
1561     }
1562   }
1563 
1564   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1565     return MCDisassembler::Fail;
1566 
1567   if (type) {
1568     Inst.addOperand(MCOperand::CreateReg(0));
1569     Inst.addOperand(MCOperand::CreateImm(U | (imm << 4) | Rm));
1570   } else {
1571     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1572     return MCDisassembler::Fail;
1573     Inst.addOperand(MCOperand::CreateImm(U));
1574   }
1575 
1576   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1577     return MCDisassembler::Fail;
1578 
1579   return S;
1580 }
1581 
1582 static DecodeStatus DecodeRFEInstruction(llvm::MCInst &Inst, unsigned Insn,
1583                                  uint64_t Address, const void *Decoder) {
1584   DecodeStatus S = MCDisassembler::Success;
1585 
1586   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1587   unsigned mode = fieldFromInstruction32(Insn, 23, 2);
1588 
1589   switch (mode) {
1590     case 0:
1591       mode = ARM_AM::da;
1592       break;
1593     case 1:
1594       mode = ARM_AM::ia;
1595       break;
1596     case 2:
1597       mode = ARM_AM::db;
1598       break;
1599     case 3:
1600       mode = ARM_AM::ib;
1601       break;
1602   }
1603 
1604   Inst.addOperand(MCOperand::CreateImm(mode));
1605   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1606     return MCDisassembler::Fail;
1607 
1608   return S;
1609 }
1610 
1611 static DecodeStatus DecodeMemMultipleWritebackInstruction(llvm::MCInst &Inst,
1612                                   unsigned Insn,
1613                                   uint64_t Address, const void *Decoder) {
1614   DecodeStatus S = MCDisassembler::Success;
1615 
1616   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1617   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1618   unsigned reglist = fieldFromInstruction32(Insn, 0, 16);
1619 
1620   if (pred == 0xF) {
1621     switch (Inst.getOpcode()) {
1622       case ARM::LDMDA:
1623         Inst.setOpcode(ARM::RFEDA);
1624         break;
1625       case ARM::LDMDA_UPD:
1626         Inst.setOpcode(ARM::RFEDA_UPD);
1627         break;
1628       case ARM::LDMDB:
1629         Inst.setOpcode(ARM::RFEDB);
1630         break;
1631       case ARM::LDMDB_UPD:
1632         Inst.setOpcode(ARM::RFEDB_UPD);
1633         break;
1634       case ARM::LDMIA:
1635         Inst.setOpcode(ARM::RFEIA);
1636         break;
1637       case ARM::LDMIA_UPD:
1638         Inst.setOpcode(ARM::RFEIA_UPD);
1639         break;
1640       case ARM::LDMIB:
1641         Inst.setOpcode(ARM::RFEIB);
1642         break;
1643       case ARM::LDMIB_UPD:
1644         Inst.setOpcode(ARM::RFEIB_UPD);
1645         break;
1646       case ARM::STMDA:
1647         Inst.setOpcode(ARM::SRSDA);
1648         break;
1649       case ARM::STMDA_UPD:
1650         Inst.setOpcode(ARM::SRSDA_UPD);
1651         break;
1652       case ARM::STMDB:
1653         Inst.setOpcode(ARM::SRSDB);
1654         break;
1655       case ARM::STMDB_UPD:
1656         Inst.setOpcode(ARM::SRSDB_UPD);
1657         break;
1658       case ARM::STMIA:
1659         Inst.setOpcode(ARM::SRSIA);
1660         break;
1661       case ARM::STMIA_UPD:
1662         Inst.setOpcode(ARM::SRSIA_UPD);
1663         break;
1664       case ARM::STMIB:
1665         Inst.setOpcode(ARM::SRSIB);
1666         break;
1667       case ARM::STMIB_UPD:
1668         Inst.setOpcode(ARM::SRSIB_UPD);
1669         break;
1670       default:
1671         if (!Check(S, MCDisassembler::Fail)) return MCDisassembler::Fail;
1672     }
1673 
1674     // For stores (which become SRS's, the only operand is the mode.
1675     if (fieldFromInstruction32(Insn, 20, 1) == 0) {
1676       Inst.addOperand(
1677           MCOperand::CreateImm(fieldFromInstruction32(Insn, 0, 4)));
1678       return S;
1679     }
1680 
1681     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
1682   }
1683 
1684   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1685     return MCDisassembler::Fail;
1686   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1687     return MCDisassembler::Fail; // Tied
1688   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1689     return MCDisassembler::Fail;
1690   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
1691     return MCDisassembler::Fail;
1692 
1693   return S;
1694 }
1695 
1696 static DecodeStatus DecodeCPSInstruction(llvm::MCInst &Inst, unsigned Insn,
1697                                  uint64_t Address, const void *Decoder) {
1698   unsigned imod = fieldFromInstruction32(Insn, 18, 2);
1699   unsigned M = fieldFromInstruction32(Insn, 17, 1);
1700   unsigned iflags = fieldFromInstruction32(Insn, 6, 3);
1701   unsigned mode = fieldFromInstruction32(Insn, 0, 5);
1702 
1703   DecodeStatus S = MCDisassembler::Success;
1704 
1705   // imod == '01' --> UNPREDICTABLE
1706   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
1707   // return failure here.  The '01' imod value is unprintable, so there's
1708   // nothing useful we could do even if we returned UNPREDICTABLE.
1709 
1710   if (imod == 1) return MCDisassembler::Fail;
1711 
1712   if (imod && M) {
1713     Inst.setOpcode(ARM::CPS3p);
1714     Inst.addOperand(MCOperand::CreateImm(imod));
1715     Inst.addOperand(MCOperand::CreateImm(iflags));
1716     Inst.addOperand(MCOperand::CreateImm(mode));
1717   } else if (imod && !M) {
1718     Inst.setOpcode(ARM::CPS2p);
1719     Inst.addOperand(MCOperand::CreateImm(imod));
1720     Inst.addOperand(MCOperand::CreateImm(iflags));
1721     if (mode) S = MCDisassembler::SoftFail;
1722   } else if (!imod && M) {
1723     Inst.setOpcode(ARM::CPS1p);
1724     Inst.addOperand(MCOperand::CreateImm(mode));
1725     if (iflags) S = MCDisassembler::SoftFail;
1726   } else {
1727     // imod == '00' && M == '0' --> UNPREDICTABLE
1728     Inst.setOpcode(ARM::CPS1p);
1729     Inst.addOperand(MCOperand::CreateImm(mode));
1730     S = MCDisassembler::SoftFail;
1731   }
1732 
1733   return S;
1734 }
1735 
1736 static DecodeStatus DecodeT2CPSInstruction(llvm::MCInst &Inst, unsigned Insn,
1737                                  uint64_t Address, const void *Decoder) {
1738   unsigned imod = fieldFromInstruction32(Insn, 9, 2);
1739   unsigned M = fieldFromInstruction32(Insn, 8, 1);
1740   unsigned iflags = fieldFromInstruction32(Insn, 5, 3);
1741   unsigned mode = fieldFromInstruction32(Insn, 0, 5);
1742 
1743   DecodeStatus S = MCDisassembler::Success;
1744 
1745   // imod == '01' --> UNPREDICTABLE
1746   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
1747   // return failure here.  The '01' imod value is unprintable, so there's
1748   // nothing useful we could do even if we returned UNPREDICTABLE.
1749 
1750   if (imod == 1) return MCDisassembler::Fail;
1751 
1752   if (imod && M) {
1753     Inst.setOpcode(ARM::t2CPS3p);
1754     Inst.addOperand(MCOperand::CreateImm(imod));
1755     Inst.addOperand(MCOperand::CreateImm(iflags));
1756     Inst.addOperand(MCOperand::CreateImm(mode));
1757   } else if (imod && !M) {
1758     Inst.setOpcode(ARM::t2CPS2p);
1759     Inst.addOperand(MCOperand::CreateImm(imod));
1760     Inst.addOperand(MCOperand::CreateImm(iflags));
1761     if (mode) S = MCDisassembler::SoftFail;
1762   } else if (!imod && M) {
1763     Inst.setOpcode(ARM::t2CPS1p);
1764     Inst.addOperand(MCOperand::CreateImm(mode));
1765     if (iflags) S = MCDisassembler::SoftFail;
1766   } else {
1767     // imod == '00' && M == '0' --> UNPREDICTABLE
1768     Inst.setOpcode(ARM::t2CPS1p);
1769     Inst.addOperand(MCOperand::CreateImm(mode));
1770     S = MCDisassembler::SoftFail;
1771   }
1772 
1773   return S;
1774 }
1775 
1776 static DecodeStatus DecodeT2MOVTWInstruction(llvm::MCInst &Inst, unsigned Insn,
1777                                  uint64_t Address, const void *Decoder) {
1778   DecodeStatus S = MCDisassembler::Success;
1779 
1780   unsigned Rd = fieldFromInstruction32(Insn, 8, 4);
1781   unsigned imm = 0;
1782 
1783   imm |= (fieldFromInstruction32(Insn, 0, 8) << 0);
1784   imm |= (fieldFromInstruction32(Insn, 12, 3) << 8);
1785   imm |= (fieldFromInstruction32(Insn, 16, 4) << 12);
1786   imm |= (fieldFromInstruction32(Insn, 26, 1) << 11);
1787 
1788   if (Inst.getOpcode() == ARM::t2MOVTi16)
1789     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
1790       return MCDisassembler::Fail;
1791   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
1792     return MCDisassembler::Fail;
1793 
1794   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
1795     Inst.addOperand(MCOperand::CreateImm(imm));
1796 
1797   return S;
1798 }
1799 
1800 static DecodeStatus DecodeArmMOVTWInstruction(llvm::MCInst &Inst, unsigned Insn,
1801                                  uint64_t Address, const void *Decoder) {
1802   DecodeStatus S = MCDisassembler::Success;
1803 
1804   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1805   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1806   unsigned imm = 0;
1807 
1808   imm |= (fieldFromInstruction32(Insn, 0, 12) << 0);
1809   imm |= (fieldFromInstruction32(Insn, 16, 4) << 12);
1810 
1811   if (Inst.getOpcode() == ARM::MOVTi16)
1812     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
1813       return MCDisassembler::Fail;
1814   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
1815     return MCDisassembler::Fail;
1816 
1817   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
1818     Inst.addOperand(MCOperand::CreateImm(imm));
1819 
1820   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1821     return MCDisassembler::Fail;
1822 
1823   return S;
1824 }
1825 
1826 static DecodeStatus DecodeSMLAInstruction(llvm::MCInst &Inst, unsigned Insn,
1827                                  uint64_t Address, const void *Decoder) {
1828   DecodeStatus S = MCDisassembler::Success;
1829 
1830   unsigned Rd = fieldFromInstruction32(Insn, 16, 4);
1831   unsigned Rn = fieldFromInstruction32(Insn, 0, 4);
1832   unsigned Rm = fieldFromInstruction32(Insn, 8, 4);
1833   unsigned Ra = fieldFromInstruction32(Insn, 12, 4);
1834   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1835 
1836   if (pred == 0xF)
1837     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
1838 
1839   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
1840     return MCDisassembler::Fail;
1841   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
1842     return MCDisassembler::Fail;
1843   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1844     return MCDisassembler::Fail;
1845   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
1846     return MCDisassembler::Fail;
1847 
1848   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1849     return MCDisassembler::Fail;
1850 
1851   return S;
1852 }
1853 
1854 static DecodeStatus DecodeAddrModeImm12Operand(llvm::MCInst &Inst, unsigned Val,
1855                            uint64_t Address, const void *Decoder) {
1856   DecodeStatus S = MCDisassembler::Success;
1857 
1858   unsigned add = fieldFromInstruction32(Val, 12, 1);
1859   unsigned imm = fieldFromInstruction32(Val, 0, 12);
1860   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
1861 
1862   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1863     return MCDisassembler::Fail;
1864 
1865   if (!add) imm *= -1;
1866   if (imm == 0 && !add) imm = INT32_MIN;
1867   Inst.addOperand(MCOperand::CreateImm(imm));
1868   if (Rn == 15)
1869     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
1870 
1871   return S;
1872 }
1873 
1874 static DecodeStatus DecodeAddrMode5Operand(llvm::MCInst &Inst, unsigned Val,
1875                                    uint64_t Address, const void *Decoder) {
1876   DecodeStatus S = MCDisassembler::Success;
1877 
1878   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
1879   unsigned U = fieldFromInstruction32(Val, 8, 1);
1880   unsigned imm = fieldFromInstruction32(Val, 0, 8);
1881 
1882   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1883     return MCDisassembler::Fail;
1884 
1885   if (U)
1886     Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
1887   else
1888     Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
1889 
1890   return S;
1891 }
1892 
1893 static DecodeStatus DecodeAddrMode7Operand(llvm::MCInst &Inst, unsigned Val,
1894                                    uint64_t Address, const void *Decoder) {
1895   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
1896 }
1897 
1898 static DecodeStatus
1899 DecodeBranchImmInstruction(llvm::MCInst &Inst, unsigned Insn,
1900                            uint64_t Address, const void *Decoder) {
1901   DecodeStatus S = MCDisassembler::Success;
1902 
1903   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1904   unsigned imm = fieldFromInstruction32(Insn, 0, 24) << 2;
1905 
1906   if (pred == 0xF) {
1907     Inst.setOpcode(ARM::BLXi);
1908     imm |= fieldFromInstruction32(Insn, 24, 1) << 1;
1909     Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1910     return S;
1911   }
1912 
1913   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8, true,
1914                                 4, Inst, Decoder))
1915     Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1916   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1917     return MCDisassembler::Fail;
1918 
1919   return S;
1920 }
1921 
1922 
1923 static DecodeStatus DecodeVCVTImmOperand(llvm::MCInst &Inst, unsigned Val,
1924                                  uint64_t Address, const void *Decoder) {
1925   Inst.addOperand(MCOperand::CreateImm(64 - Val));
1926   return MCDisassembler::Success;
1927 }
1928 
1929 static DecodeStatus DecodeAddrMode6Operand(llvm::MCInst &Inst, unsigned Val,
1930                                    uint64_t Address, const void *Decoder) {
1931   DecodeStatus S = MCDisassembler::Success;
1932 
1933   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
1934   unsigned align = fieldFromInstruction32(Val, 4, 2);
1935 
1936   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1937     return MCDisassembler::Fail;
1938   if (!align)
1939     Inst.addOperand(MCOperand::CreateImm(0));
1940   else
1941     Inst.addOperand(MCOperand::CreateImm(4 << align));
1942 
1943   return S;
1944 }
1945 
1946 static DecodeStatus DecodeVLDInstruction(llvm::MCInst &Inst, unsigned Insn,
1947                                    uint64_t Address, const void *Decoder) {
1948   DecodeStatus S = MCDisassembler::Success;
1949 
1950   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1951   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1952   unsigned wb = fieldFromInstruction32(Insn, 16, 4);
1953   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1954   Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
1955   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1956 
1957   // First output register
1958   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
1959     return MCDisassembler::Fail;
1960 
1961   // Second output register
1962   switch (Inst.getOpcode()) {
1963     case ARM::VLD1q8:
1964     case ARM::VLD1q16:
1965     case ARM::VLD1q32:
1966     case ARM::VLD1q64:
1967     case ARM::VLD1q8_UPD:
1968     case ARM::VLD1q16_UPD:
1969     case ARM::VLD1q32_UPD:
1970     case ARM::VLD1q64_UPD:
1971     case ARM::VLD1d8T:
1972     case ARM::VLD1d16T:
1973     case ARM::VLD1d32T:
1974     case ARM::VLD1d64T:
1975     case ARM::VLD1d8T_UPD:
1976     case ARM::VLD1d16T_UPD:
1977     case ARM::VLD1d32T_UPD:
1978     case ARM::VLD1d64T_UPD:
1979     case ARM::VLD1d8Q:
1980     case ARM::VLD1d16Q:
1981     case ARM::VLD1d32Q:
1982     case ARM::VLD1d64Q:
1983     case ARM::VLD1d8Q_UPD:
1984     case ARM::VLD1d16Q_UPD:
1985     case ARM::VLD1d32Q_UPD:
1986     case ARM::VLD1d64Q_UPD:
1987     case ARM::VLD2d8:
1988     case ARM::VLD2d16:
1989     case ARM::VLD2d32:
1990     case ARM::VLD2d8_UPD:
1991     case ARM::VLD2d16_UPD:
1992     case ARM::VLD2d32_UPD:
1993     case ARM::VLD2q8:
1994     case ARM::VLD2q16:
1995     case ARM::VLD2q32:
1996     case ARM::VLD2q8_UPD:
1997     case ARM::VLD2q16_UPD:
1998     case ARM::VLD2q32_UPD:
1999     case ARM::VLD3d8:
2000     case ARM::VLD3d16:
2001     case ARM::VLD3d32:
2002     case ARM::VLD3d8_UPD:
2003     case ARM::VLD3d16_UPD:
2004     case ARM::VLD3d32_UPD:
2005     case ARM::VLD4d8:
2006     case ARM::VLD4d16:
2007     case ARM::VLD4d32:
2008     case ARM::VLD4d8_UPD:
2009     case ARM::VLD4d16_UPD:
2010     case ARM::VLD4d32_UPD:
2011       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2012         return MCDisassembler::Fail;
2013       break;
2014     case ARM::VLD2b8:
2015     case ARM::VLD2b16:
2016     case ARM::VLD2b32:
2017     case ARM::VLD2b8_UPD:
2018     case ARM::VLD2b16_UPD:
2019     case ARM::VLD2b32_UPD:
2020     case ARM::VLD3q8:
2021     case ARM::VLD3q16:
2022     case ARM::VLD3q32:
2023     case ARM::VLD3q8_UPD:
2024     case ARM::VLD3q16_UPD:
2025     case ARM::VLD3q32_UPD:
2026     case ARM::VLD4q8:
2027     case ARM::VLD4q16:
2028     case ARM::VLD4q32:
2029     case ARM::VLD4q8_UPD:
2030     case ARM::VLD4q16_UPD:
2031     case ARM::VLD4q32_UPD:
2032       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2033         return MCDisassembler::Fail;
2034     default:
2035       break;
2036   }
2037 
2038   // Third output register
2039   switch(Inst.getOpcode()) {
2040     case ARM::VLD1d8T:
2041     case ARM::VLD1d16T:
2042     case ARM::VLD1d32T:
2043     case ARM::VLD1d64T:
2044     case ARM::VLD1d8T_UPD:
2045     case ARM::VLD1d16T_UPD:
2046     case ARM::VLD1d32T_UPD:
2047     case ARM::VLD1d64T_UPD:
2048     case ARM::VLD1d8Q:
2049     case ARM::VLD1d16Q:
2050     case ARM::VLD1d32Q:
2051     case ARM::VLD1d64Q:
2052     case ARM::VLD1d8Q_UPD:
2053     case ARM::VLD1d16Q_UPD:
2054     case ARM::VLD1d32Q_UPD:
2055     case ARM::VLD1d64Q_UPD:
2056     case ARM::VLD2q8:
2057     case ARM::VLD2q16:
2058     case ARM::VLD2q32:
2059     case ARM::VLD2q8_UPD:
2060     case ARM::VLD2q16_UPD:
2061     case ARM::VLD2q32_UPD:
2062     case ARM::VLD3d8:
2063     case ARM::VLD3d16:
2064     case ARM::VLD3d32:
2065     case ARM::VLD3d8_UPD:
2066     case ARM::VLD3d16_UPD:
2067     case ARM::VLD3d32_UPD:
2068     case ARM::VLD4d8:
2069     case ARM::VLD4d16:
2070     case ARM::VLD4d32:
2071     case ARM::VLD4d8_UPD:
2072     case ARM::VLD4d16_UPD:
2073     case ARM::VLD4d32_UPD:
2074       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2075         return MCDisassembler::Fail;
2076       break;
2077     case ARM::VLD3q8:
2078     case ARM::VLD3q16:
2079     case ARM::VLD3q32:
2080     case ARM::VLD3q8_UPD:
2081     case ARM::VLD3q16_UPD:
2082     case ARM::VLD3q32_UPD:
2083     case ARM::VLD4q8:
2084     case ARM::VLD4q16:
2085     case ARM::VLD4q32:
2086     case ARM::VLD4q8_UPD:
2087     case ARM::VLD4q16_UPD:
2088     case ARM::VLD4q32_UPD:
2089       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2090         return MCDisassembler::Fail;
2091       break;
2092     default:
2093       break;
2094   }
2095 
2096   // Fourth output register
2097   switch (Inst.getOpcode()) {
2098     case ARM::VLD1d8Q:
2099     case ARM::VLD1d16Q:
2100     case ARM::VLD1d32Q:
2101     case ARM::VLD1d64Q:
2102     case ARM::VLD1d8Q_UPD:
2103     case ARM::VLD1d16Q_UPD:
2104     case ARM::VLD1d32Q_UPD:
2105     case ARM::VLD1d64Q_UPD:
2106     case ARM::VLD2q8:
2107     case ARM::VLD2q16:
2108     case ARM::VLD2q32:
2109     case ARM::VLD2q8_UPD:
2110     case ARM::VLD2q16_UPD:
2111     case ARM::VLD2q32_UPD:
2112     case ARM::VLD4d8:
2113     case ARM::VLD4d16:
2114     case ARM::VLD4d32:
2115     case ARM::VLD4d8_UPD:
2116     case ARM::VLD4d16_UPD:
2117     case ARM::VLD4d32_UPD:
2118       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2119         return MCDisassembler::Fail;
2120       break;
2121     case ARM::VLD4q8:
2122     case ARM::VLD4q16:
2123     case ARM::VLD4q32:
2124     case ARM::VLD4q8_UPD:
2125     case ARM::VLD4q16_UPD:
2126     case ARM::VLD4q32_UPD:
2127       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2128         return MCDisassembler::Fail;
2129       break;
2130     default:
2131       break;
2132   }
2133 
2134   // Writeback operand
2135   switch (Inst.getOpcode()) {
2136     case ARM::VLD1d8_UPD:
2137     case ARM::VLD1d16_UPD:
2138     case ARM::VLD1d32_UPD:
2139     case ARM::VLD1d64_UPD:
2140     case ARM::VLD1q8_UPD:
2141     case ARM::VLD1q16_UPD:
2142     case ARM::VLD1q32_UPD:
2143     case ARM::VLD1q64_UPD:
2144     case ARM::VLD1d8T_UPD:
2145     case ARM::VLD1d16T_UPD:
2146     case ARM::VLD1d32T_UPD:
2147     case ARM::VLD1d64T_UPD:
2148     case ARM::VLD1d8Q_UPD:
2149     case ARM::VLD1d16Q_UPD:
2150     case ARM::VLD1d32Q_UPD:
2151     case ARM::VLD1d64Q_UPD:
2152     case ARM::VLD2d8_UPD:
2153     case ARM::VLD2d16_UPD:
2154     case ARM::VLD2d32_UPD:
2155     case ARM::VLD2q8_UPD:
2156     case ARM::VLD2q16_UPD:
2157     case ARM::VLD2q32_UPD:
2158     case ARM::VLD2b8_UPD:
2159     case ARM::VLD2b16_UPD:
2160     case ARM::VLD2b32_UPD:
2161     case ARM::VLD3d8_UPD:
2162     case ARM::VLD3d16_UPD:
2163     case ARM::VLD3d32_UPD:
2164     case ARM::VLD3q8_UPD:
2165     case ARM::VLD3q16_UPD:
2166     case ARM::VLD3q32_UPD:
2167     case ARM::VLD4d8_UPD:
2168     case ARM::VLD4d16_UPD:
2169     case ARM::VLD4d32_UPD:
2170     case ARM::VLD4q8_UPD:
2171     case ARM::VLD4q16_UPD:
2172     case ARM::VLD4q32_UPD:
2173       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2174         return MCDisassembler::Fail;
2175       break;
2176     default:
2177       break;
2178   }
2179 
2180   // AddrMode6 Base (register+alignment)
2181   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2182     return MCDisassembler::Fail;
2183 
2184   // AddrMode6 Offset (register)
2185   if (Rm == 0xD)
2186     Inst.addOperand(MCOperand::CreateReg(0));
2187   else if (Rm != 0xF) {
2188     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2189       return MCDisassembler::Fail;
2190   }
2191 
2192   return S;
2193 }
2194 
2195 static DecodeStatus DecodeVSTInstruction(llvm::MCInst &Inst, unsigned Insn,
2196                                  uint64_t Address, const void *Decoder) {
2197   DecodeStatus S = MCDisassembler::Success;
2198 
2199   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2200   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2201   unsigned wb = fieldFromInstruction32(Insn, 16, 4);
2202   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2203   Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
2204   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2205 
2206   // Writeback Operand
2207   switch (Inst.getOpcode()) {
2208     case ARM::VST1d8_UPD:
2209     case ARM::VST1d16_UPD:
2210     case ARM::VST1d32_UPD:
2211     case ARM::VST1d64_UPD:
2212     case ARM::VST1q8_UPD:
2213     case ARM::VST1q16_UPD:
2214     case ARM::VST1q32_UPD:
2215     case ARM::VST1q64_UPD:
2216     case ARM::VST1d8T_UPD:
2217     case ARM::VST1d16T_UPD:
2218     case ARM::VST1d32T_UPD:
2219     case ARM::VST1d64T_UPD:
2220     case ARM::VST1d8Q_UPD:
2221     case ARM::VST1d16Q_UPD:
2222     case ARM::VST1d32Q_UPD:
2223     case ARM::VST1d64Q_UPD:
2224     case ARM::VST2d8_UPD:
2225     case ARM::VST2d16_UPD:
2226     case ARM::VST2d32_UPD:
2227     case ARM::VST2q8_UPD:
2228     case ARM::VST2q16_UPD:
2229     case ARM::VST2q32_UPD:
2230     case ARM::VST2b8_UPD:
2231     case ARM::VST2b16_UPD:
2232     case ARM::VST2b32_UPD:
2233     case ARM::VST3d8_UPD:
2234     case ARM::VST3d16_UPD:
2235     case ARM::VST3d32_UPD:
2236     case ARM::VST3q8_UPD:
2237     case ARM::VST3q16_UPD:
2238     case ARM::VST3q32_UPD:
2239     case ARM::VST4d8_UPD:
2240     case ARM::VST4d16_UPD:
2241     case ARM::VST4d32_UPD:
2242     case ARM::VST4q8_UPD:
2243     case ARM::VST4q16_UPD:
2244     case ARM::VST4q32_UPD:
2245       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2246         return MCDisassembler::Fail;
2247       break;
2248     default:
2249       break;
2250   }
2251 
2252   // AddrMode6 Base (register+alignment)
2253   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2254     return MCDisassembler::Fail;
2255 
2256   // AddrMode6 Offset (register)
2257   if (Rm == 0xD)
2258     Inst.addOperand(MCOperand::CreateReg(0));
2259   else if (Rm != 0xF) {
2260     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2261     return MCDisassembler::Fail;
2262   }
2263 
2264   // First input register
2265   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2266     return MCDisassembler::Fail;
2267 
2268   // Second input register
2269   switch (Inst.getOpcode()) {
2270     case ARM::VST1q8:
2271     case ARM::VST1q16:
2272     case ARM::VST1q32:
2273     case ARM::VST1q64:
2274     case ARM::VST1q8_UPD:
2275     case ARM::VST1q16_UPD:
2276     case ARM::VST1q32_UPD:
2277     case ARM::VST1q64_UPD:
2278     case ARM::VST1d8T:
2279     case ARM::VST1d16T:
2280     case ARM::VST1d32T:
2281     case ARM::VST1d64T:
2282     case ARM::VST1d8T_UPD:
2283     case ARM::VST1d16T_UPD:
2284     case ARM::VST1d32T_UPD:
2285     case ARM::VST1d64T_UPD:
2286     case ARM::VST1d8Q:
2287     case ARM::VST1d16Q:
2288     case ARM::VST1d32Q:
2289     case ARM::VST1d64Q:
2290     case ARM::VST1d8Q_UPD:
2291     case ARM::VST1d16Q_UPD:
2292     case ARM::VST1d32Q_UPD:
2293     case ARM::VST1d64Q_UPD:
2294     case ARM::VST2d8:
2295     case ARM::VST2d16:
2296     case ARM::VST2d32:
2297     case ARM::VST2d8_UPD:
2298     case ARM::VST2d16_UPD:
2299     case ARM::VST2d32_UPD:
2300     case ARM::VST2q8:
2301     case ARM::VST2q16:
2302     case ARM::VST2q32:
2303     case ARM::VST2q8_UPD:
2304     case ARM::VST2q16_UPD:
2305     case ARM::VST2q32_UPD:
2306     case ARM::VST3d8:
2307     case ARM::VST3d16:
2308     case ARM::VST3d32:
2309     case ARM::VST3d8_UPD:
2310     case ARM::VST3d16_UPD:
2311     case ARM::VST3d32_UPD:
2312     case ARM::VST4d8:
2313     case ARM::VST4d16:
2314     case ARM::VST4d32:
2315     case ARM::VST4d8_UPD:
2316     case ARM::VST4d16_UPD:
2317     case ARM::VST4d32_UPD:
2318       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2319         return MCDisassembler::Fail;
2320       break;
2321     case ARM::VST2b8:
2322     case ARM::VST2b16:
2323     case ARM::VST2b32:
2324     case ARM::VST2b8_UPD:
2325     case ARM::VST2b16_UPD:
2326     case ARM::VST2b32_UPD:
2327     case ARM::VST3q8:
2328     case ARM::VST3q16:
2329     case ARM::VST3q32:
2330     case ARM::VST3q8_UPD:
2331     case ARM::VST3q16_UPD:
2332     case ARM::VST3q32_UPD:
2333     case ARM::VST4q8:
2334     case ARM::VST4q16:
2335     case ARM::VST4q32:
2336     case ARM::VST4q8_UPD:
2337     case ARM::VST4q16_UPD:
2338     case ARM::VST4q32_UPD:
2339       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2340         return MCDisassembler::Fail;
2341       break;
2342     default:
2343       break;
2344   }
2345 
2346   // Third input register
2347   switch (Inst.getOpcode()) {
2348     case ARM::VST1d8T:
2349     case ARM::VST1d16T:
2350     case ARM::VST1d32T:
2351     case ARM::VST1d64T:
2352     case ARM::VST1d8T_UPD:
2353     case ARM::VST1d16T_UPD:
2354     case ARM::VST1d32T_UPD:
2355     case ARM::VST1d64T_UPD:
2356     case ARM::VST1d8Q:
2357     case ARM::VST1d16Q:
2358     case ARM::VST1d32Q:
2359     case ARM::VST1d64Q:
2360     case ARM::VST1d8Q_UPD:
2361     case ARM::VST1d16Q_UPD:
2362     case ARM::VST1d32Q_UPD:
2363     case ARM::VST1d64Q_UPD:
2364     case ARM::VST2q8:
2365     case ARM::VST2q16:
2366     case ARM::VST2q32:
2367     case ARM::VST2q8_UPD:
2368     case ARM::VST2q16_UPD:
2369     case ARM::VST2q32_UPD:
2370     case ARM::VST3d8:
2371     case ARM::VST3d16:
2372     case ARM::VST3d32:
2373     case ARM::VST3d8_UPD:
2374     case ARM::VST3d16_UPD:
2375     case ARM::VST3d32_UPD:
2376     case ARM::VST4d8:
2377     case ARM::VST4d16:
2378     case ARM::VST4d32:
2379     case ARM::VST4d8_UPD:
2380     case ARM::VST4d16_UPD:
2381     case ARM::VST4d32_UPD:
2382       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2383         return MCDisassembler::Fail;
2384       break;
2385     case ARM::VST3q8:
2386     case ARM::VST3q16:
2387     case ARM::VST3q32:
2388     case ARM::VST3q8_UPD:
2389     case ARM::VST3q16_UPD:
2390     case ARM::VST3q32_UPD:
2391     case ARM::VST4q8:
2392     case ARM::VST4q16:
2393     case ARM::VST4q32:
2394     case ARM::VST4q8_UPD:
2395     case ARM::VST4q16_UPD:
2396     case ARM::VST4q32_UPD:
2397       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2398         return MCDisassembler::Fail;
2399       break;
2400     default:
2401       break;
2402   }
2403 
2404   // Fourth input register
2405   switch (Inst.getOpcode()) {
2406     case ARM::VST1d8Q:
2407     case ARM::VST1d16Q:
2408     case ARM::VST1d32Q:
2409     case ARM::VST1d64Q:
2410     case ARM::VST1d8Q_UPD:
2411     case ARM::VST1d16Q_UPD:
2412     case ARM::VST1d32Q_UPD:
2413     case ARM::VST1d64Q_UPD:
2414     case ARM::VST2q8:
2415     case ARM::VST2q16:
2416     case ARM::VST2q32:
2417     case ARM::VST2q8_UPD:
2418     case ARM::VST2q16_UPD:
2419     case ARM::VST2q32_UPD:
2420     case ARM::VST4d8:
2421     case ARM::VST4d16:
2422     case ARM::VST4d32:
2423     case ARM::VST4d8_UPD:
2424     case ARM::VST4d16_UPD:
2425     case ARM::VST4d32_UPD:
2426       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2427         return MCDisassembler::Fail;
2428       break;
2429     case ARM::VST4q8:
2430     case ARM::VST4q16:
2431     case ARM::VST4q32:
2432     case ARM::VST4q8_UPD:
2433     case ARM::VST4q16_UPD:
2434     case ARM::VST4q32_UPD:
2435       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2436         return MCDisassembler::Fail;
2437       break;
2438     default:
2439       break;
2440   }
2441 
2442   return S;
2443 }
2444 
2445 static DecodeStatus DecodeVLD1DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2446                                     uint64_t Address, const void *Decoder) {
2447   DecodeStatus S = MCDisassembler::Success;
2448 
2449   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2450   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2451   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2452   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2453   unsigned align = fieldFromInstruction32(Insn, 4, 1);
2454   unsigned size = fieldFromInstruction32(Insn, 6, 2);
2455   unsigned regs = fieldFromInstruction32(Insn, 5, 1) + 1;
2456 
2457   align *= (1 << size);
2458 
2459   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2460     return MCDisassembler::Fail;
2461   if (regs == 2) {
2462     if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2463       return MCDisassembler::Fail;
2464   }
2465   if (Rm != 0xF) {
2466     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2467       return MCDisassembler::Fail;
2468   }
2469 
2470   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2471     return MCDisassembler::Fail;
2472   Inst.addOperand(MCOperand::CreateImm(align));
2473 
2474   if (Rm == 0xD)
2475     Inst.addOperand(MCOperand::CreateReg(0));
2476   else if (Rm != 0xF) {
2477     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2478       return MCDisassembler::Fail;
2479   }
2480 
2481   return S;
2482 }
2483 
2484 static DecodeStatus DecodeVLD2DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2485                                     uint64_t Address, const void *Decoder) {
2486   DecodeStatus S = MCDisassembler::Success;
2487 
2488   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2489   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2490   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2491   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2492   unsigned align = fieldFromInstruction32(Insn, 4, 1);
2493   unsigned size = 1 << fieldFromInstruction32(Insn, 6, 2);
2494   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2495   align *= 2*size;
2496 
2497   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2498     return MCDisassembler::Fail;
2499   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
2500     return MCDisassembler::Fail;
2501   if (Rm != 0xF) {
2502     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2503       return MCDisassembler::Fail;
2504   }
2505 
2506   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2507     return MCDisassembler::Fail;
2508   Inst.addOperand(MCOperand::CreateImm(align));
2509 
2510   if (Rm == 0xD)
2511     Inst.addOperand(MCOperand::CreateReg(0));
2512   else if (Rm != 0xF) {
2513     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2514       return MCDisassembler::Fail;
2515   }
2516 
2517   return S;
2518 }
2519 
2520 static DecodeStatus DecodeVLD3DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2521                                     uint64_t Address, const void *Decoder) {
2522   DecodeStatus S = MCDisassembler::Success;
2523 
2524   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2525   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2526   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2527   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2528   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2529 
2530   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2531     return MCDisassembler::Fail;
2532   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
2533     return MCDisassembler::Fail;
2534   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
2535     return MCDisassembler::Fail;
2536   if (Rm != 0xF) {
2537     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2538       return MCDisassembler::Fail;
2539   }
2540 
2541   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2542     return MCDisassembler::Fail;
2543   Inst.addOperand(MCOperand::CreateImm(0));
2544 
2545   if (Rm == 0xD)
2546     Inst.addOperand(MCOperand::CreateReg(0));
2547   else if (Rm != 0xF) {
2548     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2549       return MCDisassembler::Fail;
2550   }
2551 
2552   return S;
2553 }
2554 
2555 static DecodeStatus DecodeVLD4DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2556                                     uint64_t Address, const void *Decoder) {
2557   DecodeStatus S = MCDisassembler::Success;
2558 
2559   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2560   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2561   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2562   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2563   unsigned size = fieldFromInstruction32(Insn, 6, 2);
2564   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2565   unsigned align = fieldFromInstruction32(Insn, 4, 1);
2566 
2567   if (size == 0x3) {
2568     size = 4;
2569     align = 16;
2570   } else {
2571     if (size == 2) {
2572       size = 1 << size;
2573       align *= 8;
2574     } else {
2575       size = 1 << size;
2576       align *= 4*size;
2577     }
2578   }
2579 
2580   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2581     return MCDisassembler::Fail;
2582   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
2583     return MCDisassembler::Fail;
2584   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
2585     return MCDisassembler::Fail;
2586   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
2587     return MCDisassembler::Fail;
2588   if (Rm != 0xF) {
2589     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2590       return MCDisassembler::Fail;
2591   }
2592 
2593   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2594     return MCDisassembler::Fail;
2595   Inst.addOperand(MCOperand::CreateImm(align));
2596 
2597   if (Rm == 0xD)
2598     Inst.addOperand(MCOperand::CreateReg(0));
2599   else if (Rm != 0xF) {
2600     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2601       return MCDisassembler::Fail;
2602   }
2603 
2604   return S;
2605 }
2606 
2607 static DecodeStatus
2608 DecodeNEONModImmInstruction(llvm::MCInst &Inst, unsigned Insn,
2609                             uint64_t Address, const void *Decoder) {
2610   DecodeStatus S = MCDisassembler::Success;
2611 
2612   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2613   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2614   unsigned imm = fieldFromInstruction32(Insn, 0, 4);
2615   imm |= fieldFromInstruction32(Insn, 16, 3) << 4;
2616   imm |= fieldFromInstruction32(Insn, 24, 1) << 7;
2617   imm |= fieldFromInstruction32(Insn, 8, 4) << 8;
2618   imm |= fieldFromInstruction32(Insn, 5, 1) << 12;
2619   unsigned Q = fieldFromInstruction32(Insn, 6, 1);
2620 
2621   if (Q) {
2622     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
2623     return MCDisassembler::Fail;
2624   } else {
2625     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2626     return MCDisassembler::Fail;
2627   }
2628 
2629   Inst.addOperand(MCOperand::CreateImm(imm));
2630 
2631   switch (Inst.getOpcode()) {
2632     case ARM::VORRiv4i16:
2633     case ARM::VORRiv2i32:
2634     case ARM::VBICiv4i16:
2635     case ARM::VBICiv2i32:
2636       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2637         return MCDisassembler::Fail;
2638       break;
2639     case ARM::VORRiv8i16:
2640     case ARM::VORRiv4i32:
2641     case ARM::VBICiv8i16:
2642     case ARM::VBICiv4i32:
2643       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
2644         return MCDisassembler::Fail;
2645       break;
2646     default:
2647       break;
2648   }
2649 
2650   return S;
2651 }
2652 
2653 static DecodeStatus DecodeVSHLMaxInstruction(llvm::MCInst &Inst, unsigned Insn,
2654                                         uint64_t Address, const void *Decoder) {
2655   DecodeStatus S = MCDisassembler::Success;
2656 
2657   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2658   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2659   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2660   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2661   unsigned size = fieldFromInstruction32(Insn, 18, 2);
2662 
2663   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
2664     return MCDisassembler::Fail;
2665   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
2666     return MCDisassembler::Fail;
2667   Inst.addOperand(MCOperand::CreateImm(8 << size));
2668 
2669   return S;
2670 }
2671 
2672 static DecodeStatus DecodeShiftRight8Imm(llvm::MCInst &Inst, unsigned Val,
2673                                uint64_t Address, const void *Decoder) {
2674   Inst.addOperand(MCOperand::CreateImm(8 - Val));
2675   return MCDisassembler::Success;
2676 }
2677 
2678 static DecodeStatus DecodeShiftRight16Imm(llvm::MCInst &Inst, unsigned Val,
2679                                uint64_t Address, const void *Decoder) {
2680   Inst.addOperand(MCOperand::CreateImm(16 - Val));
2681   return MCDisassembler::Success;
2682 }
2683 
2684 static DecodeStatus DecodeShiftRight32Imm(llvm::MCInst &Inst, unsigned Val,
2685                                uint64_t Address, const void *Decoder) {
2686   Inst.addOperand(MCOperand::CreateImm(32 - Val));
2687   return MCDisassembler::Success;
2688 }
2689 
2690 static DecodeStatus DecodeShiftRight64Imm(llvm::MCInst &Inst, unsigned Val,
2691                                uint64_t Address, const void *Decoder) {
2692   Inst.addOperand(MCOperand::CreateImm(64 - Val));
2693   return MCDisassembler::Success;
2694 }
2695 
2696 static DecodeStatus DecodeTBLInstruction(llvm::MCInst &Inst, unsigned Insn,
2697                                uint64_t Address, const void *Decoder) {
2698   DecodeStatus S = MCDisassembler::Success;
2699 
2700   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2701   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2702   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2703   Rn |= fieldFromInstruction32(Insn, 7, 1) << 4;
2704   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2705   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2706   unsigned op = fieldFromInstruction32(Insn, 6, 1);
2707   unsigned length = fieldFromInstruction32(Insn, 8, 2) + 1;
2708 
2709   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2710     return MCDisassembler::Fail;
2711   if (op) {
2712     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2713     return MCDisassembler::Fail; // Writeback
2714   }
2715 
2716   for (unsigned i = 0; i < length; ++i) {
2717     if (!Check(S, DecodeDPRRegisterClass(Inst, (Rn+i)%32, Address, Decoder)))
2718     return MCDisassembler::Fail;
2719   }
2720 
2721   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
2722     return MCDisassembler::Fail;
2723 
2724   return S;
2725 }
2726 
2727 static DecodeStatus DecodeThumbAddSpecialReg(llvm::MCInst &Inst, uint16_t Insn,
2728                                      uint64_t Address, const void *Decoder) {
2729   DecodeStatus S = MCDisassembler::Success;
2730 
2731   unsigned dst = fieldFromInstruction16(Insn, 8, 3);
2732   unsigned imm = fieldFromInstruction16(Insn, 0, 8);
2733 
2734   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
2735     return MCDisassembler::Fail;
2736 
2737   switch(Inst.getOpcode()) {
2738     default:
2739       return MCDisassembler::Fail;
2740     case ARM::tADR:
2741       break; // tADR does not explicitly represent the PC as an operand.
2742     case ARM::tADDrSPi:
2743       Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2744       break;
2745   }
2746 
2747   Inst.addOperand(MCOperand::CreateImm(imm));
2748   return S;
2749 }
2750 
2751 static DecodeStatus DecodeThumbBROperand(llvm::MCInst &Inst, unsigned Val,
2752                                  uint64_t Address, const void *Decoder) {
2753   Inst.addOperand(MCOperand::CreateImm(SignExtend32<12>(Val << 1)));
2754   return MCDisassembler::Success;
2755 }
2756 
2757 static DecodeStatus DecodeT2BROperand(llvm::MCInst &Inst, unsigned Val,
2758                                  uint64_t Address, const void *Decoder) {
2759   Inst.addOperand(MCOperand::CreateImm(SignExtend32<21>(Val)));
2760   return MCDisassembler::Success;
2761 }
2762 
2763 static DecodeStatus DecodeThumbCmpBROperand(llvm::MCInst &Inst, unsigned Val,
2764                                  uint64_t Address, const void *Decoder) {
2765   Inst.addOperand(MCOperand::CreateImm(SignExtend32<7>(Val << 1)));
2766   return MCDisassembler::Success;
2767 }
2768 
2769 static DecodeStatus DecodeThumbAddrModeRR(llvm::MCInst &Inst, unsigned Val,
2770                                  uint64_t Address, const void *Decoder) {
2771   DecodeStatus S = MCDisassembler::Success;
2772 
2773   unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2774   unsigned Rm = fieldFromInstruction32(Val, 3, 3);
2775 
2776   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
2777     return MCDisassembler::Fail;
2778   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
2779     return MCDisassembler::Fail;
2780 
2781   return S;
2782 }
2783 
2784 static DecodeStatus DecodeThumbAddrModeIS(llvm::MCInst &Inst, unsigned Val,
2785                                   uint64_t Address, const void *Decoder) {
2786   DecodeStatus S = MCDisassembler::Success;
2787 
2788   unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2789   unsigned imm = fieldFromInstruction32(Val, 3, 5);
2790 
2791   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
2792     return MCDisassembler::Fail;
2793   Inst.addOperand(MCOperand::CreateImm(imm));
2794 
2795   return S;
2796 }
2797 
2798 static DecodeStatus DecodeThumbAddrModePC(llvm::MCInst &Inst, unsigned Val,
2799                                   uint64_t Address, const void *Decoder) {
2800   unsigned imm = Val << 2;
2801 
2802   Inst.addOperand(MCOperand::CreateImm(imm));
2803   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
2804 
2805   return MCDisassembler::Success;
2806 }
2807 
2808 static DecodeStatus DecodeThumbAddrModeSP(llvm::MCInst &Inst, unsigned Val,
2809                                   uint64_t Address, const void *Decoder) {
2810   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2811   Inst.addOperand(MCOperand::CreateImm(Val));
2812 
2813   return MCDisassembler::Success;
2814 }
2815 
2816 static DecodeStatus DecodeT2AddrModeSOReg(llvm::MCInst &Inst, unsigned Val,
2817                                   uint64_t Address, const void *Decoder) {
2818   DecodeStatus S = MCDisassembler::Success;
2819 
2820   unsigned Rn = fieldFromInstruction32(Val, 6, 4);
2821   unsigned Rm = fieldFromInstruction32(Val, 2, 4);
2822   unsigned imm = fieldFromInstruction32(Val, 0, 2);
2823 
2824   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2825     return MCDisassembler::Fail;
2826   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
2827     return MCDisassembler::Fail;
2828   Inst.addOperand(MCOperand::CreateImm(imm));
2829 
2830   return S;
2831 }
2832 
2833 static DecodeStatus DecodeT2LoadShift(llvm::MCInst &Inst, unsigned Insn,
2834                               uint64_t Address, const void *Decoder) {
2835   DecodeStatus S = MCDisassembler::Success;
2836 
2837   switch (Inst.getOpcode()) {
2838     case ARM::t2PLDs:
2839     case ARM::t2PLDWs:
2840     case ARM::t2PLIs:
2841       break;
2842     default: {
2843       unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2844       if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
2845     return MCDisassembler::Fail;
2846     }
2847   }
2848 
2849   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2850   if (Rn == 0xF) {
2851     switch (Inst.getOpcode()) {
2852       case ARM::t2LDRBs:
2853         Inst.setOpcode(ARM::t2LDRBpci);
2854         break;
2855       case ARM::t2LDRHs:
2856         Inst.setOpcode(ARM::t2LDRHpci);
2857         break;
2858       case ARM::t2LDRSHs:
2859         Inst.setOpcode(ARM::t2LDRSHpci);
2860         break;
2861       case ARM::t2LDRSBs:
2862         Inst.setOpcode(ARM::t2LDRSBpci);
2863         break;
2864       case ARM::t2PLDs:
2865         Inst.setOpcode(ARM::t2PLDi12);
2866         Inst.addOperand(MCOperand::CreateReg(ARM::PC));
2867         break;
2868       default:
2869         return MCDisassembler::Fail;
2870     }
2871 
2872     int imm = fieldFromInstruction32(Insn, 0, 12);
2873     if (!fieldFromInstruction32(Insn, 23, 1)) imm *= -1;
2874     Inst.addOperand(MCOperand::CreateImm(imm));
2875 
2876     return S;
2877   }
2878 
2879   unsigned addrmode = fieldFromInstruction32(Insn, 4, 2);
2880   addrmode |= fieldFromInstruction32(Insn, 0, 4) << 2;
2881   addrmode |= fieldFromInstruction32(Insn, 16, 4) << 6;
2882   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
2883     return MCDisassembler::Fail;
2884 
2885   return S;
2886 }
2887 
2888 static DecodeStatus DecodeT2Imm8S4(llvm::MCInst &Inst, unsigned Val,
2889                            uint64_t Address, const void *Decoder) {
2890   int imm = Val & 0xFF;
2891   if (!(Val & 0x100)) imm *= -1;
2892   Inst.addOperand(MCOperand::CreateImm(imm << 2));
2893 
2894   return MCDisassembler::Success;
2895 }
2896 
2897 static DecodeStatus DecodeT2AddrModeImm8s4(llvm::MCInst &Inst, unsigned Val,
2898                                    uint64_t Address, const void *Decoder) {
2899   DecodeStatus S = MCDisassembler::Success;
2900 
2901   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2902   unsigned imm = fieldFromInstruction32(Val, 0, 9);
2903 
2904   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2905     return MCDisassembler::Fail;
2906   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
2907     return MCDisassembler::Fail;
2908 
2909   return S;
2910 }
2911 
2912 static DecodeStatus DecodeT2AddrModeImm0_1020s4(llvm::MCInst &Inst,unsigned Val,
2913                                    uint64_t Address, const void *Decoder) {
2914   DecodeStatus S = MCDisassembler::Success;
2915 
2916   unsigned Rn = fieldFromInstruction32(Val, 8, 4);
2917   unsigned imm = fieldFromInstruction32(Val, 0, 8);
2918 
2919   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2920     return MCDisassembler::Fail;
2921 
2922   Inst.addOperand(MCOperand::CreateImm(imm));
2923 
2924   return S;
2925 }
2926 
2927 static DecodeStatus DecodeT2Imm8(llvm::MCInst &Inst, unsigned Val,
2928                          uint64_t Address, const void *Decoder) {
2929   int imm = Val & 0xFF;
2930   if (Val == 0)
2931     imm = INT32_MIN;
2932   else if (!(Val & 0x100))
2933     imm *= -1;
2934   Inst.addOperand(MCOperand::CreateImm(imm));
2935 
2936   return MCDisassembler::Success;
2937 }
2938 
2939 
2940 static DecodeStatus DecodeT2AddrModeImm8(llvm::MCInst &Inst, unsigned Val,
2941                                  uint64_t Address, const void *Decoder) {
2942   DecodeStatus S = MCDisassembler::Success;
2943 
2944   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2945   unsigned imm = fieldFromInstruction32(Val, 0, 9);
2946 
2947   // Some instructions always use an additive offset.
2948   switch (Inst.getOpcode()) {
2949     case ARM::t2LDRT:
2950     case ARM::t2LDRBT:
2951     case ARM::t2LDRHT:
2952     case ARM::t2LDRSBT:
2953     case ARM::t2LDRSHT:
2954     case ARM::t2STRT:
2955     case ARM::t2STRBT:
2956     case ARM::t2STRHT:
2957       imm |= 0x100;
2958       break;
2959     default:
2960       break;
2961   }
2962 
2963   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2964     return MCDisassembler::Fail;
2965   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
2966     return MCDisassembler::Fail;
2967 
2968   return S;
2969 }
2970 
2971 static DecodeStatus DecodeT2LdStPre(llvm::MCInst &Inst, unsigned Insn,
2972                                     uint64_t Address, const void *Decoder) {
2973   DecodeStatus S = MCDisassembler::Success;
2974 
2975   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2976   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2977   unsigned addr = fieldFromInstruction32(Insn, 0, 8);
2978   addr |= fieldFromInstruction32(Insn, 9, 1) << 8;
2979   addr |= Rn << 9;
2980   unsigned load = fieldFromInstruction32(Insn, 20, 1);
2981 
2982   if (!load) {
2983     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2984       return MCDisassembler::Fail;
2985   }
2986 
2987   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
2988     return MCDisassembler::Fail;
2989 
2990   if (load) {
2991     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2992       return MCDisassembler::Fail;
2993   }
2994 
2995   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
2996     return MCDisassembler::Fail;
2997 
2998   return S;
2999 }
3000 
3001 static DecodeStatus DecodeT2AddrModeImm12(llvm::MCInst &Inst, unsigned Val,
3002                                   uint64_t Address, const void *Decoder) {
3003   DecodeStatus S = MCDisassembler::Success;
3004 
3005   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
3006   unsigned imm = fieldFromInstruction32(Val, 0, 12);
3007 
3008   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3009     return MCDisassembler::Fail;
3010   Inst.addOperand(MCOperand::CreateImm(imm));
3011 
3012   return S;
3013 }
3014 
3015 
3016 static DecodeStatus DecodeThumbAddSPImm(llvm::MCInst &Inst, uint16_t Insn,
3017                                 uint64_t Address, const void *Decoder) {
3018   unsigned imm = fieldFromInstruction16(Insn, 0, 7);
3019 
3020   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
3021   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
3022   Inst.addOperand(MCOperand::CreateImm(imm));
3023 
3024   return MCDisassembler::Success;
3025 }
3026 
3027 static DecodeStatus DecodeThumbAddSPReg(llvm::MCInst &Inst, uint16_t Insn,
3028                                 uint64_t Address, const void *Decoder) {
3029   DecodeStatus S = MCDisassembler::Success;
3030 
3031   if (Inst.getOpcode() == ARM::tADDrSP) {
3032     unsigned Rdm = fieldFromInstruction16(Insn, 0, 3);
3033     Rdm |= fieldFromInstruction16(Insn, 7, 1) << 3;
3034 
3035     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
3036     return MCDisassembler::Fail;
3037     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
3038     return MCDisassembler::Fail;
3039     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
3040   } else if (Inst.getOpcode() == ARM::tADDspr) {
3041     unsigned Rm = fieldFromInstruction16(Insn, 3, 4);
3042 
3043     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
3044     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
3045     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3046     return MCDisassembler::Fail;
3047   }
3048 
3049   return S;
3050 }
3051 
3052 static DecodeStatus DecodeThumbCPS(llvm::MCInst &Inst, uint16_t Insn,
3053                            uint64_t Address, const void *Decoder) {
3054   unsigned imod = fieldFromInstruction16(Insn, 4, 1) | 0x2;
3055   unsigned flags = fieldFromInstruction16(Insn, 0, 3);
3056 
3057   Inst.addOperand(MCOperand::CreateImm(imod));
3058   Inst.addOperand(MCOperand::CreateImm(flags));
3059 
3060   return MCDisassembler::Success;
3061 }
3062 
3063 static DecodeStatus DecodePostIdxReg(llvm::MCInst &Inst, unsigned Insn,
3064                              uint64_t Address, const void *Decoder) {
3065   DecodeStatus S = MCDisassembler::Success;
3066   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3067   unsigned add = fieldFromInstruction32(Insn, 4, 1);
3068 
3069   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3070     return MCDisassembler::Fail;
3071   Inst.addOperand(MCOperand::CreateImm(add));
3072 
3073   return S;
3074 }
3075 
3076 static DecodeStatus DecodeThumbBLXOffset(llvm::MCInst &Inst, unsigned Val,
3077                                  uint64_t Address, const void *Decoder) {
3078   if (!tryAddingSymbolicOperand(Address,
3079                                 (Address & ~2u) + SignExtend32<22>(Val << 1) + 4,
3080                                 true, 4, Inst, Decoder))
3081     Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
3082   return MCDisassembler::Success;
3083 }
3084 
3085 static DecodeStatus DecodeCoprocessor(llvm::MCInst &Inst, unsigned Val,
3086                               uint64_t Address, const void *Decoder) {
3087   if (Val == 0xA || Val == 0xB)
3088     return MCDisassembler::Fail;
3089 
3090   Inst.addOperand(MCOperand::CreateImm(Val));
3091   return MCDisassembler::Success;
3092 }
3093 
3094 static DecodeStatus
3095 DecodeThumbTableBranch(llvm::MCInst &Inst, unsigned Insn,
3096                        uint64_t Address, const void *Decoder) {
3097   DecodeStatus S = MCDisassembler::Success;
3098 
3099   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3100   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3101 
3102   if (Rn == ARM::SP) S = MCDisassembler::SoftFail;
3103   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3104     return MCDisassembler::Fail;
3105   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3106     return MCDisassembler::Fail;
3107   return S;
3108 }
3109 
3110 static DecodeStatus
3111 DecodeThumb2BCCInstruction(llvm::MCInst &Inst, unsigned Insn,
3112                            uint64_t Address, const void *Decoder) {
3113   DecodeStatus S = MCDisassembler::Success;
3114 
3115   unsigned pred = fieldFromInstruction32(Insn, 22, 4);
3116   if (pred == 0xE || pred == 0xF) {
3117     unsigned opc = fieldFromInstruction32(Insn, 4, 28);
3118     switch (opc) {
3119       default:
3120         return MCDisassembler::Fail;
3121       case 0xf3bf8f4:
3122         Inst.setOpcode(ARM::t2DSB);
3123         break;
3124       case 0xf3bf8f5:
3125         Inst.setOpcode(ARM::t2DMB);
3126         break;
3127       case 0xf3bf8f6:
3128         Inst.setOpcode(ARM::t2ISB);
3129         break;
3130     }
3131 
3132     unsigned imm = fieldFromInstruction32(Insn, 0, 4);
3133     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
3134   }
3135 
3136   unsigned brtarget = fieldFromInstruction32(Insn, 0, 11) << 1;
3137   brtarget |= fieldFromInstruction32(Insn, 11, 1) << 19;
3138   brtarget |= fieldFromInstruction32(Insn, 13, 1) << 18;
3139   brtarget |= fieldFromInstruction32(Insn, 16, 6) << 12;
3140   brtarget |= fieldFromInstruction32(Insn, 26, 1) << 20;
3141 
3142   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
3143     return MCDisassembler::Fail;
3144   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3145     return MCDisassembler::Fail;
3146 
3147   return S;
3148 }
3149 
3150 // Decode a shifted immediate operand.  These basically consist
3151 // of an 8-bit value, and a 4-bit directive that specifies either
3152 // a splat operation or a rotation.
3153 static DecodeStatus DecodeT2SOImm(llvm::MCInst &Inst, unsigned Val,
3154                           uint64_t Address, const void *Decoder) {
3155   unsigned ctrl = fieldFromInstruction32(Val, 10, 2);
3156   if (ctrl == 0) {
3157     unsigned byte = fieldFromInstruction32(Val, 8, 2);
3158     unsigned imm = fieldFromInstruction32(Val, 0, 8);
3159     switch (byte) {
3160       case 0:
3161         Inst.addOperand(MCOperand::CreateImm(imm));
3162         break;
3163       case 1:
3164         Inst.addOperand(MCOperand::CreateImm((imm << 16) | imm));
3165         break;
3166       case 2:
3167         Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 8)));
3168         break;
3169       case 3:
3170         Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 16) |
3171                                              (imm << 8)  |  imm));
3172         break;
3173     }
3174   } else {
3175     unsigned unrot = fieldFromInstruction32(Val, 0, 7) | 0x80;
3176     unsigned rot = fieldFromInstruction32(Val, 7, 5);
3177     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
3178     Inst.addOperand(MCOperand::CreateImm(imm));
3179   }
3180 
3181   return MCDisassembler::Success;
3182 }
3183 
3184 static DecodeStatus
3185 DecodeThumbBCCTargetOperand(llvm::MCInst &Inst, unsigned Val,
3186                             uint64_t Address, const void *Decoder){
3187   Inst.addOperand(MCOperand::CreateImm(Val << 1));
3188   return MCDisassembler::Success;
3189 }
3190 
3191 static DecodeStatus DecodeThumbBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
3192                                        uint64_t Address, const void *Decoder){
3193   Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
3194   return MCDisassembler::Success;
3195 }
3196 
3197 static DecodeStatus DecodeMemBarrierOption(llvm::MCInst &Inst, unsigned Val,
3198                                    uint64_t Address, const void *Decoder) {
3199   switch (Val) {
3200   default:
3201     return MCDisassembler::Fail;
3202   case 0xF: // SY
3203   case 0xE: // ST
3204   case 0xB: // ISH
3205   case 0xA: // ISHST
3206   case 0x7: // NSH
3207   case 0x6: // NSHST
3208   case 0x3: // OSH
3209   case 0x2: // OSHST
3210     break;
3211   }
3212 
3213   Inst.addOperand(MCOperand::CreateImm(Val));
3214   return MCDisassembler::Success;
3215 }
3216 
3217 static DecodeStatus DecodeMSRMask(llvm::MCInst &Inst, unsigned Val,
3218                           uint64_t Address, const void *Decoder) {
3219   if (!Val) return MCDisassembler::Fail;
3220   Inst.addOperand(MCOperand::CreateImm(Val));
3221   return MCDisassembler::Success;
3222 }
3223 
3224 static DecodeStatus DecodeDoubleRegLoad(llvm::MCInst &Inst, unsigned Insn,
3225                                         uint64_t Address, const void *Decoder) {
3226   DecodeStatus S = MCDisassembler::Success;
3227 
3228   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3229   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3230   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3231 
3232   if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return MCDisassembler::Fail;
3233 
3234   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3235     return MCDisassembler::Fail;
3236   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
3237     return MCDisassembler::Fail;
3238   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3239     return MCDisassembler::Fail;
3240   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3241     return MCDisassembler::Fail;
3242 
3243   return S;
3244 }
3245 
3246 
3247 static DecodeStatus DecodeDoubleRegStore(llvm::MCInst &Inst, unsigned Insn,
3248                                          uint64_t Address, const void *Decoder){
3249   DecodeStatus S = MCDisassembler::Success;
3250 
3251   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3252   unsigned Rt = fieldFromInstruction32(Insn, 0, 4);
3253   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3254   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3255 
3256   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
3257     return MCDisassembler::Fail;
3258 
3259   if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return MCDisassembler::Fail;
3260   if (Rd == Rn || Rd == Rt || Rd == Rt+1) return MCDisassembler::Fail;
3261 
3262   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3263     return MCDisassembler::Fail;
3264   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
3265     return MCDisassembler::Fail;
3266   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3267     return MCDisassembler::Fail;
3268   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3269     return MCDisassembler::Fail;
3270 
3271   return S;
3272 }
3273 
3274 static DecodeStatus DecodeLDRPreImm(llvm::MCInst &Inst, unsigned Insn,
3275                             uint64_t Address, const void *Decoder) {
3276   DecodeStatus S = MCDisassembler::Success;
3277 
3278   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3279   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3280   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3281   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3282   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3283   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3284 
3285   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3286 
3287   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3288     return MCDisassembler::Fail;
3289   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3290     return MCDisassembler::Fail;
3291   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
3292     return MCDisassembler::Fail;
3293   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3294     return MCDisassembler::Fail;
3295 
3296   return S;
3297 }
3298 
3299 static DecodeStatus DecodeLDRPreReg(llvm::MCInst &Inst, unsigned Insn,
3300                             uint64_t Address, const void *Decoder) {
3301   DecodeStatus S = MCDisassembler::Success;
3302 
3303   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3304   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3305   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3306   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3307   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3308   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3309   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3310 
3311   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3312   if (Rm == 0xF) S = MCDisassembler::SoftFail;
3313 
3314   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3315     return MCDisassembler::Fail;
3316   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3317     return MCDisassembler::Fail;
3318   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
3319     return MCDisassembler::Fail;
3320   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3321     return MCDisassembler::Fail;
3322 
3323   return S;
3324 }
3325 
3326 
3327 static DecodeStatus DecodeSTRPreImm(llvm::MCInst &Inst, unsigned Insn,
3328                             uint64_t Address, const void *Decoder) {
3329   DecodeStatus S = MCDisassembler::Success;
3330 
3331   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3332   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3333   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3334   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3335   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3336   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3337 
3338   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3339 
3340   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3341     return MCDisassembler::Fail;
3342   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3343     return MCDisassembler::Fail;
3344   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
3345     return MCDisassembler::Fail;
3346   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3347     return MCDisassembler::Fail;
3348 
3349   return S;
3350 }
3351 
3352 static DecodeStatus DecodeSTRPreReg(llvm::MCInst &Inst, unsigned Insn,
3353                             uint64_t Address, const void *Decoder) {
3354   DecodeStatus S = MCDisassembler::Success;
3355 
3356   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3357   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3358   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3359   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3360   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3361   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3362 
3363   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3364 
3365   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3366     return MCDisassembler::Fail;
3367   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3368     return MCDisassembler::Fail;
3369   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
3370     return MCDisassembler::Fail;
3371   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3372     return MCDisassembler::Fail;
3373 
3374   return S;
3375 }
3376 
3377 static DecodeStatus DecodeVLD1LN(llvm::MCInst &Inst, unsigned Insn,
3378                          uint64_t Address, const void *Decoder) {
3379   DecodeStatus S = MCDisassembler::Success;
3380 
3381   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3382   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3383   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3384   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3385   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3386 
3387   unsigned align = 0;
3388   unsigned index = 0;
3389   switch (size) {
3390     default:
3391       return MCDisassembler::Fail;
3392     case 0:
3393       if (fieldFromInstruction32(Insn, 4, 1))
3394         return MCDisassembler::Fail; // UNDEFINED
3395       index = fieldFromInstruction32(Insn, 5, 3);
3396       break;
3397     case 1:
3398       if (fieldFromInstruction32(Insn, 5, 1))
3399         return MCDisassembler::Fail; // UNDEFINED
3400       index = fieldFromInstruction32(Insn, 6, 2);
3401       if (fieldFromInstruction32(Insn, 4, 1))
3402         align = 2;
3403       break;
3404     case 2:
3405       if (fieldFromInstruction32(Insn, 6, 1))
3406         return MCDisassembler::Fail; // UNDEFINED
3407       index = fieldFromInstruction32(Insn, 7, 1);
3408       if (fieldFromInstruction32(Insn, 4, 2) != 0)
3409         align = 4;
3410   }
3411 
3412   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3413     return MCDisassembler::Fail;
3414   if (Rm != 0xF) { // Writeback
3415     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3416       return MCDisassembler::Fail;
3417   }
3418   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3419     return MCDisassembler::Fail;
3420   Inst.addOperand(MCOperand::CreateImm(align));
3421   if (Rm != 0xF) {
3422     if (Rm != 0xD) {
3423       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3424         return MCDisassembler::Fail;
3425     } else
3426       Inst.addOperand(MCOperand::CreateReg(0));
3427   }
3428 
3429   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3430     return MCDisassembler::Fail;
3431   Inst.addOperand(MCOperand::CreateImm(index));
3432 
3433   return S;
3434 }
3435 
3436 static DecodeStatus DecodeVST1LN(llvm::MCInst &Inst, unsigned Insn,
3437                          uint64_t Address, const void *Decoder) {
3438   DecodeStatus S = MCDisassembler::Success;
3439 
3440   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3441   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3442   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3443   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3444   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3445 
3446   unsigned align = 0;
3447   unsigned index = 0;
3448   switch (size) {
3449     default:
3450       return MCDisassembler::Fail;
3451     case 0:
3452       if (fieldFromInstruction32(Insn, 4, 1))
3453         return MCDisassembler::Fail; // UNDEFINED
3454       index = fieldFromInstruction32(Insn, 5, 3);
3455       break;
3456     case 1:
3457       if (fieldFromInstruction32(Insn, 5, 1))
3458         return MCDisassembler::Fail; // UNDEFINED
3459       index = fieldFromInstruction32(Insn, 6, 2);
3460       if (fieldFromInstruction32(Insn, 4, 1))
3461         align = 2;
3462       break;
3463     case 2:
3464       if (fieldFromInstruction32(Insn, 6, 1))
3465         return MCDisassembler::Fail; // UNDEFINED
3466       index = fieldFromInstruction32(Insn, 7, 1);
3467       if (fieldFromInstruction32(Insn, 4, 2) != 0)
3468         align = 4;
3469   }
3470 
3471   if (Rm != 0xF) { // Writeback
3472     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3473     return MCDisassembler::Fail;
3474   }
3475   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3476     return MCDisassembler::Fail;
3477   Inst.addOperand(MCOperand::CreateImm(align));
3478   if (Rm != 0xF) {
3479     if (Rm != 0xD) {
3480       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3481     return MCDisassembler::Fail;
3482     } else
3483       Inst.addOperand(MCOperand::CreateReg(0));
3484   }
3485 
3486   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3487     return MCDisassembler::Fail;
3488   Inst.addOperand(MCOperand::CreateImm(index));
3489 
3490   return S;
3491 }
3492 
3493 
3494 static DecodeStatus DecodeVLD2LN(llvm::MCInst &Inst, unsigned Insn,
3495                          uint64_t Address, const void *Decoder) {
3496   DecodeStatus S = MCDisassembler::Success;
3497 
3498   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3499   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3500   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3501   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3502   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3503 
3504   unsigned align = 0;
3505   unsigned index = 0;
3506   unsigned inc = 1;
3507   switch (size) {
3508     default:
3509       return MCDisassembler::Fail;
3510     case 0:
3511       index = fieldFromInstruction32(Insn, 5, 3);
3512       if (fieldFromInstruction32(Insn, 4, 1))
3513         align = 2;
3514       break;
3515     case 1:
3516       index = fieldFromInstruction32(Insn, 6, 2);
3517       if (fieldFromInstruction32(Insn, 4, 1))
3518         align = 4;
3519       if (fieldFromInstruction32(Insn, 5, 1))
3520         inc = 2;
3521       break;
3522     case 2:
3523       if (fieldFromInstruction32(Insn, 5, 1))
3524         return MCDisassembler::Fail; // UNDEFINED
3525       index = fieldFromInstruction32(Insn, 7, 1);
3526       if (fieldFromInstruction32(Insn, 4, 1) != 0)
3527         align = 8;
3528       if (fieldFromInstruction32(Insn, 6, 1))
3529         inc = 2;
3530       break;
3531   }
3532 
3533   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3534     return MCDisassembler::Fail;
3535   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3536     return MCDisassembler::Fail;
3537   if (Rm != 0xF) { // Writeback
3538     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3539       return MCDisassembler::Fail;
3540   }
3541   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3542     return MCDisassembler::Fail;
3543   Inst.addOperand(MCOperand::CreateImm(align));
3544   if (Rm != 0xF) {
3545     if (Rm != 0xD) {
3546       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3547         return MCDisassembler::Fail;
3548     } else
3549       Inst.addOperand(MCOperand::CreateReg(0));
3550   }
3551 
3552   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3553     return MCDisassembler::Fail;
3554   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3555     return MCDisassembler::Fail;
3556   Inst.addOperand(MCOperand::CreateImm(index));
3557 
3558   return S;
3559 }
3560 
3561 static DecodeStatus DecodeVST2LN(llvm::MCInst &Inst, unsigned Insn,
3562                          uint64_t Address, const void *Decoder) {
3563   DecodeStatus S = MCDisassembler::Success;
3564 
3565   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3566   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3567   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3568   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3569   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3570 
3571   unsigned align = 0;
3572   unsigned index = 0;
3573   unsigned inc = 1;
3574   switch (size) {
3575     default:
3576       return MCDisassembler::Fail;
3577     case 0:
3578       index = fieldFromInstruction32(Insn, 5, 3);
3579       if (fieldFromInstruction32(Insn, 4, 1))
3580         align = 2;
3581       break;
3582     case 1:
3583       index = fieldFromInstruction32(Insn, 6, 2);
3584       if (fieldFromInstruction32(Insn, 4, 1))
3585         align = 4;
3586       if (fieldFromInstruction32(Insn, 5, 1))
3587         inc = 2;
3588       break;
3589     case 2:
3590       if (fieldFromInstruction32(Insn, 5, 1))
3591         return MCDisassembler::Fail; // UNDEFINED
3592       index = fieldFromInstruction32(Insn, 7, 1);
3593       if (fieldFromInstruction32(Insn, 4, 1) != 0)
3594         align = 8;
3595       if (fieldFromInstruction32(Insn, 6, 1))
3596         inc = 2;
3597       break;
3598   }
3599 
3600   if (Rm != 0xF) { // Writeback
3601     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3602       return MCDisassembler::Fail;
3603   }
3604   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3605     return MCDisassembler::Fail;
3606   Inst.addOperand(MCOperand::CreateImm(align));
3607   if (Rm != 0xF) {
3608     if (Rm != 0xD) {
3609       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3610         return MCDisassembler::Fail;
3611     } else
3612       Inst.addOperand(MCOperand::CreateReg(0));
3613   }
3614 
3615   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3616     return MCDisassembler::Fail;
3617   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3618     return MCDisassembler::Fail;
3619   Inst.addOperand(MCOperand::CreateImm(index));
3620 
3621   return S;
3622 }
3623 
3624 
3625 static DecodeStatus DecodeVLD3LN(llvm::MCInst &Inst, unsigned Insn,
3626                          uint64_t Address, const void *Decoder) {
3627   DecodeStatus S = MCDisassembler::Success;
3628 
3629   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3630   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3631   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3632   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3633   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3634 
3635   unsigned align = 0;
3636   unsigned index = 0;
3637   unsigned inc = 1;
3638   switch (size) {
3639     default:
3640       return MCDisassembler::Fail;
3641     case 0:
3642       if (fieldFromInstruction32(Insn, 4, 1))
3643         return MCDisassembler::Fail; // UNDEFINED
3644       index = fieldFromInstruction32(Insn, 5, 3);
3645       break;
3646     case 1:
3647       if (fieldFromInstruction32(Insn, 4, 1))
3648         return MCDisassembler::Fail; // UNDEFINED
3649       index = fieldFromInstruction32(Insn, 6, 2);
3650       if (fieldFromInstruction32(Insn, 5, 1))
3651         inc = 2;
3652       break;
3653     case 2:
3654       if (fieldFromInstruction32(Insn, 4, 2))
3655         return MCDisassembler::Fail; // UNDEFINED
3656       index = fieldFromInstruction32(Insn, 7, 1);
3657       if (fieldFromInstruction32(Insn, 6, 1))
3658         inc = 2;
3659       break;
3660   }
3661 
3662   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3663     return MCDisassembler::Fail;
3664   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3665     return MCDisassembler::Fail;
3666   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3667     return MCDisassembler::Fail;
3668 
3669   if (Rm != 0xF) { // Writeback
3670     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3671     return MCDisassembler::Fail;
3672   }
3673   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3674     return MCDisassembler::Fail;
3675   Inst.addOperand(MCOperand::CreateImm(align));
3676   if (Rm != 0xF) {
3677     if (Rm != 0xD) {
3678       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3679     return MCDisassembler::Fail;
3680     } else
3681       Inst.addOperand(MCOperand::CreateReg(0));
3682   }
3683 
3684   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3685     return MCDisassembler::Fail;
3686   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3687     return MCDisassembler::Fail;
3688   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3689     return MCDisassembler::Fail;
3690   Inst.addOperand(MCOperand::CreateImm(index));
3691 
3692   return S;
3693 }
3694 
3695 static DecodeStatus DecodeVST3LN(llvm::MCInst &Inst, unsigned Insn,
3696                          uint64_t Address, const void *Decoder) {
3697   DecodeStatus S = MCDisassembler::Success;
3698 
3699   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3700   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3701   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3702   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3703   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3704 
3705   unsigned align = 0;
3706   unsigned index = 0;
3707   unsigned inc = 1;
3708   switch (size) {
3709     default:
3710       return MCDisassembler::Fail;
3711     case 0:
3712       if (fieldFromInstruction32(Insn, 4, 1))
3713         return MCDisassembler::Fail; // UNDEFINED
3714       index = fieldFromInstruction32(Insn, 5, 3);
3715       break;
3716     case 1:
3717       if (fieldFromInstruction32(Insn, 4, 1))
3718         return MCDisassembler::Fail; // UNDEFINED
3719       index = fieldFromInstruction32(Insn, 6, 2);
3720       if (fieldFromInstruction32(Insn, 5, 1))
3721         inc = 2;
3722       break;
3723     case 2:
3724       if (fieldFromInstruction32(Insn, 4, 2))
3725         return MCDisassembler::Fail; // UNDEFINED
3726       index = fieldFromInstruction32(Insn, 7, 1);
3727       if (fieldFromInstruction32(Insn, 6, 1))
3728         inc = 2;
3729       break;
3730   }
3731 
3732   if (Rm != 0xF) { // Writeback
3733     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3734     return MCDisassembler::Fail;
3735   }
3736   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3737     return MCDisassembler::Fail;
3738   Inst.addOperand(MCOperand::CreateImm(align));
3739   if (Rm != 0xF) {
3740     if (Rm != 0xD) {
3741       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3742     return MCDisassembler::Fail;
3743     } else
3744       Inst.addOperand(MCOperand::CreateReg(0));
3745   }
3746 
3747   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3748     return MCDisassembler::Fail;
3749   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3750     return MCDisassembler::Fail;
3751   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3752     return MCDisassembler::Fail;
3753   Inst.addOperand(MCOperand::CreateImm(index));
3754 
3755   return S;
3756 }
3757 
3758 
3759 static DecodeStatus DecodeVLD4LN(llvm::MCInst &Inst, unsigned Insn,
3760                          uint64_t Address, const void *Decoder) {
3761   DecodeStatus S = MCDisassembler::Success;
3762 
3763   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3764   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3765   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3766   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3767   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3768 
3769   unsigned align = 0;
3770   unsigned index = 0;
3771   unsigned inc = 1;
3772   switch (size) {
3773     default:
3774       return MCDisassembler::Fail;
3775     case 0:
3776       if (fieldFromInstruction32(Insn, 4, 1))
3777         align = 4;
3778       index = fieldFromInstruction32(Insn, 5, 3);
3779       break;
3780     case 1:
3781       if (fieldFromInstruction32(Insn, 4, 1))
3782         align = 8;
3783       index = fieldFromInstruction32(Insn, 6, 2);
3784       if (fieldFromInstruction32(Insn, 5, 1))
3785         inc = 2;
3786       break;
3787     case 2:
3788       if (fieldFromInstruction32(Insn, 4, 2))
3789         align = 4 << fieldFromInstruction32(Insn, 4, 2);
3790       index = fieldFromInstruction32(Insn, 7, 1);
3791       if (fieldFromInstruction32(Insn, 6, 1))
3792         inc = 2;
3793       break;
3794   }
3795 
3796   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3797     return MCDisassembler::Fail;
3798   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3799     return MCDisassembler::Fail;
3800   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3801     return MCDisassembler::Fail;
3802   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
3803     return MCDisassembler::Fail;
3804 
3805   if (Rm != 0xF) { // Writeback
3806     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3807       return MCDisassembler::Fail;
3808   }
3809   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3810     return MCDisassembler::Fail;
3811   Inst.addOperand(MCOperand::CreateImm(align));
3812   if (Rm != 0xF) {
3813     if (Rm != 0xD) {
3814       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3815         return MCDisassembler::Fail;
3816     } else
3817       Inst.addOperand(MCOperand::CreateReg(0));
3818   }
3819 
3820   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3821     return MCDisassembler::Fail;
3822   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3823     return MCDisassembler::Fail;
3824   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3825     return MCDisassembler::Fail;
3826   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
3827     return MCDisassembler::Fail;
3828   Inst.addOperand(MCOperand::CreateImm(index));
3829 
3830   return S;
3831 }
3832 
3833 static DecodeStatus DecodeVST4LN(llvm::MCInst &Inst, unsigned Insn,
3834                          uint64_t Address, const void *Decoder) {
3835   DecodeStatus S = MCDisassembler::Success;
3836 
3837   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3838   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3839   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3840   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3841   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3842 
3843   unsigned align = 0;
3844   unsigned index = 0;
3845   unsigned inc = 1;
3846   switch (size) {
3847     default:
3848       return MCDisassembler::Fail;
3849     case 0:
3850       if (fieldFromInstruction32(Insn, 4, 1))
3851         align = 4;
3852       index = fieldFromInstruction32(Insn, 5, 3);
3853       break;
3854     case 1:
3855       if (fieldFromInstruction32(Insn, 4, 1))
3856         align = 8;
3857       index = fieldFromInstruction32(Insn, 6, 2);
3858       if (fieldFromInstruction32(Insn, 5, 1))
3859         inc = 2;
3860       break;
3861     case 2:
3862       if (fieldFromInstruction32(Insn, 4, 2))
3863         align = 4 << fieldFromInstruction32(Insn, 4, 2);
3864       index = fieldFromInstruction32(Insn, 7, 1);
3865       if (fieldFromInstruction32(Insn, 6, 1))
3866         inc = 2;
3867       break;
3868   }
3869 
3870   if (Rm != 0xF) { // Writeback
3871     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3872     return MCDisassembler::Fail;
3873   }
3874   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3875     return MCDisassembler::Fail;
3876   Inst.addOperand(MCOperand::CreateImm(align));
3877   if (Rm != 0xF) {
3878     if (Rm != 0xD) {
3879       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3880     return MCDisassembler::Fail;
3881     } else
3882       Inst.addOperand(MCOperand::CreateReg(0));
3883   }
3884 
3885   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3886     return MCDisassembler::Fail;
3887   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3888     return MCDisassembler::Fail;
3889   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3890     return MCDisassembler::Fail;
3891   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
3892     return MCDisassembler::Fail;
3893   Inst.addOperand(MCOperand::CreateImm(index));
3894 
3895   return S;
3896 }
3897 
3898 static DecodeStatus DecodeVMOVSRR(llvm::MCInst &Inst, unsigned Insn,
3899                                   uint64_t Address, const void *Decoder) {
3900   DecodeStatus S = MCDisassembler::Success;
3901   unsigned Rt  = fieldFromInstruction32(Insn, 12, 4);
3902   unsigned Rt2 = fieldFromInstruction32(Insn, 16, 4);
3903   unsigned Rm  = fieldFromInstruction32(Insn,  0, 4);
3904   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3905   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
3906 
3907   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
3908     S = MCDisassembler::SoftFail;
3909 
3910   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
3911     return MCDisassembler::Fail;
3912   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
3913     return MCDisassembler::Fail;
3914   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
3915     return MCDisassembler::Fail;
3916   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
3917     return MCDisassembler::Fail;
3918   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3919     return MCDisassembler::Fail;
3920 
3921   return S;
3922 }
3923 
3924 static DecodeStatus DecodeVMOVRRS(llvm::MCInst &Inst, unsigned Insn,
3925                                   uint64_t Address, const void *Decoder) {
3926   DecodeStatus S = MCDisassembler::Success;
3927   unsigned Rt  = fieldFromInstruction32(Insn, 12, 4);
3928   unsigned Rt2 = fieldFromInstruction32(Insn, 16, 4);
3929   unsigned Rm  = fieldFromInstruction32(Insn,  0, 4);
3930   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3931   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
3932 
3933   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
3934     S = MCDisassembler::SoftFail;
3935 
3936   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
3937     return MCDisassembler::Fail;
3938   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
3939     return MCDisassembler::Fail;
3940   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
3941     return MCDisassembler::Fail;
3942   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
3943     return MCDisassembler::Fail;
3944   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3945     return MCDisassembler::Fail;
3946 
3947   return S;
3948 }
3949 
3950 static DecodeStatus DecodeIT(llvm::MCInst &Inst, unsigned Insn,
3951                              uint64_t Address, const void *Decoder) {
3952   DecodeStatus S = MCDisassembler::Success;
3953   unsigned pred = fieldFromInstruction16(Insn, 4, 4);
3954   // The InstPrinter needs to have the low bit of the predicate in
3955   // the mask operand to be able to print it properly.
3956   unsigned mask = fieldFromInstruction16(Insn, 0, 5);
3957 
3958   if (pred == 0xF) {
3959     pred = 0xE;
3960     S = MCDisassembler::SoftFail;
3961   }
3962 
3963   if ((mask & 0xF) == 0) {
3964     // Preserve the high bit of the mask, which is the low bit of
3965     // the predicate.
3966     mask &= 0x10;
3967     mask |= 0x8;
3968     S = MCDisassembler::SoftFail;
3969   }
3970 
3971   Inst.addOperand(MCOperand::CreateImm(pred));
3972   Inst.addOperand(MCOperand::CreateImm(mask));
3973   return S;
3974 }
3975 
3976 static DecodeStatus
3977 DecodeT2LDRDPreInstruction(llvm::MCInst &Inst, unsigned Insn,
3978                            uint64_t Address, const void *Decoder) {
3979   DecodeStatus S = MCDisassembler::Success;
3980 
3981   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3982   unsigned Rt2 = fieldFromInstruction32(Insn, 8, 4);
3983   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3984   unsigned addr = fieldFromInstruction32(Insn, 0, 8);
3985   unsigned W = fieldFromInstruction32(Insn, 21, 1);
3986   unsigned U = fieldFromInstruction32(Insn, 23, 1);
3987   unsigned P = fieldFromInstruction32(Insn, 24, 1);
3988   bool writeback = (W == 1) | (P == 0);
3989 
3990   addr |= (U << 8) | (Rn << 9);
3991 
3992   if (writeback && (Rn == Rt || Rn == Rt2))
3993     Check(S, MCDisassembler::SoftFail);
3994   if (Rt == Rt2)
3995     Check(S, MCDisassembler::SoftFail);
3996 
3997   // Rt
3998   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
3999     return MCDisassembler::Fail;
4000   // Rt2
4001   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
4002     return MCDisassembler::Fail;
4003   // Writeback operand
4004   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
4005     return MCDisassembler::Fail;
4006   // addr
4007   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
4008     return MCDisassembler::Fail;
4009 
4010   return S;
4011 }
4012 
4013 static DecodeStatus
4014 DecodeT2STRDPreInstruction(llvm::MCInst &Inst, unsigned Insn,
4015                            uint64_t Address, const void *Decoder) {
4016   DecodeStatus S = MCDisassembler::Success;
4017 
4018   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
4019   unsigned Rt2 = fieldFromInstruction32(Insn, 8, 4);
4020   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
4021   unsigned addr = fieldFromInstruction32(Insn, 0, 8);
4022   unsigned W = fieldFromInstruction32(Insn, 21, 1);
4023   unsigned U = fieldFromInstruction32(Insn, 23, 1);
4024   unsigned P = fieldFromInstruction32(Insn, 24, 1);
4025   bool writeback = (W == 1) | (P == 0);
4026 
4027   addr |= (U << 8) | (Rn << 9);
4028 
4029   if (writeback && (Rn == Rt || Rn == Rt2))
4030     Check(S, MCDisassembler::SoftFail);
4031 
4032   // Writeback operand
4033   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
4034     return MCDisassembler::Fail;
4035   // Rt
4036   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
4037     return MCDisassembler::Fail;
4038   // Rt2
4039   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
4040     return MCDisassembler::Fail;
4041   // addr
4042   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
4043     return MCDisassembler::Fail;
4044 
4045   return S;
4046 }
4047 
4048 static DecodeStatus DecodeT2Adr(llvm::MCInst &Inst, uint32_t Insn,
4049                                 uint64_t Address, const void *Decoder) {
4050   unsigned sign1 = fieldFromInstruction32(Insn, 21, 1);
4051   unsigned sign2 = fieldFromInstruction32(Insn, 23, 1);
4052   if (sign1 != sign2) return MCDisassembler::Fail;
4053 
4054   unsigned Val = fieldFromInstruction32(Insn, 0, 8);
4055   Val |= fieldFromInstruction32(Insn, 12, 3) << 8;
4056   Val |= fieldFromInstruction32(Insn, 26, 1) << 11;
4057   Val |= sign1 << 12;
4058   Inst.addOperand(MCOperand::CreateImm(SignExtend32<13>(Val)));
4059 
4060   return MCDisassembler::Success;
4061 }
4062 
4063 static DecodeStatus DecodeT2ShifterImmOperand(llvm::MCInst &Inst, uint32_t Val,
4064                                               uint64_t Address,
4065                                               const void *Decoder) {
4066   DecodeStatus S = MCDisassembler::Success;
4067 
4068   // Shift of "asr #32" is not allowed in Thumb2 mode.
4069   if (Val == 0x20) S = MCDisassembler::SoftFail;
4070   Inst.addOperand(MCOperand::CreateImm(Val));
4071   return S;
4072 }
4073 
4074