xref: /llvm-project/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (revision 2f2e3c47373ca2ee60d4d0810da3429443fa4aca)
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(0 && "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     case ARM::tSETEND:
602       // Some instructions (mostly conditional branches) are not
603       // allowed in IT blocks.
604       if (!ITBlock.empty())
605         S = SoftFail;
606       else
607         return Success;
608       break;
609     case ARM::tB:
610     case ARM::t2B:
611     case ARM::t2TBB:
612     case ARM::t2TBH:
613       // Some instructions (mostly unconditional branches) can
614       // only appears at the end of, or outside of, an IT.
615       if (ITBlock.size() > 1)
616         S = SoftFail;
617       break;
618     default:
619       break;
620   }
621 
622   // If we're in an IT block, base the predicate on that.  Otherwise,
623   // assume a predicate of AL.
624   unsigned CC;
625   if (!ITBlock.empty()) {
626     CC = ITBlock.back();
627     if (CC == 0xF)
628       CC = ARMCC::AL;
629     ITBlock.pop_back();
630   } else
631     CC = ARMCC::AL;
632 
633   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
634   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
635   MCInst::iterator I = MI.begin();
636   for (unsigned i = 0; i < NumOps; ++i, ++I) {
637     if (I == MI.end()) break;
638     if (OpInfo[i].isPredicate()) {
639       I = MI.insert(I, MCOperand::CreateImm(CC));
640       ++I;
641       if (CC == ARMCC::AL)
642         MI.insert(I, MCOperand::CreateReg(0));
643       else
644         MI.insert(I, MCOperand::CreateReg(ARM::CPSR));
645       return S;
646     }
647   }
648 
649   I = MI.insert(I, MCOperand::CreateImm(CC));
650   ++I;
651   if (CC == ARMCC::AL)
652     MI.insert(I, MCOperand::CreateReg(0));
653   else
654     MI.insert(I, MCOperand::CreateReg(ARM::CPSR));
655 
656   return S;
657 }
658 
659 // Thumb VFP instructions are a special case.  Because we share their
660 // encodings between ARM and Thumb modes, and they are predicable in ARM
661 // mode, the auto-generated decoder will give them an (incorrect)
662 // predicate operand.  We need to rewrite these operands based on the IT
663 // context as a post-pass.
664 void ThumbDisassembler::UpdateThumbVFPPredicate(MCInst &MI) const {
665   unsigned CC;
666   if (!ITBlock.empty()) {
667     CC = ITBlock.back();
668     ITBlock.pop_back();
669   } else
670     CC = ARMCC::AL;
671 
672   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
673   MCInst::iterator I = MI.begin();
674   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
675   for (unsigned i = 0; i < NumOps; ++i, ++I) {
676     if (OpInfo[i].isPredicate() ) {
677       I->setImm(CC);
678       ++I;
679       if (CC == ARMCC::AL)
680         I->setReg(0);
681       else
682         I->setReg(ARM::CPSR);
683       return;
684     }
685   }
686 }
687 
688 DecodeStatus ThumbDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
689                                                const MemoryObject &Region,
690                                                uint64_t Address,
691                                                raw_ostream &os,
692                                                raw_ostream &cs) const {
693   CommentStream = &cs;
694 
695   uint8_t bytes[4];
696 
697   assert((STI.getFeatureBits() & ARM::ModeThumb) &&
698          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
699 
700   // We want to read exactly 2 bytes of data.
701   if (Region.readBytes(Address, 2, (uint8_t*)bytes, NULL) == -1) {
702     Size = 0;
703     return MCDisassembler::Fail;
704   }
705 
706   uint16_t insn16 = (bytes[1] << 8) | bytes[0];
707   DecodeStatus result = decodeThumbInstruction16(MI, insn16, Address, this, STI);
708   if (result != MCDisassembler::Fail) {
709     Size = 2;
710     Check(result, AddThumbPredicate(MI));
711     return result;
712   }
713 
714   MI.clear();
715   result = decodeThumbSBitInstruction16(MI, insn16, Address, this, STI);
716   if (result) {
717     Size = 2;
718     bool InITBlock = !ITBlock.empty();
719     Check(result, AddThumbPredicate(MI));
720     AddThumb1SBit(MI, InITBlock);
721     return result;
722   }
723 
724   MI.clear();
725   result = decodeThumb2Instruction16(MI, insn16, Address, this, STI);
726   if (result != MCDisassembler::Fail) {
727     Size = 2;
728 
729     // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
730     // the Thumb predicate.
731     if (MI.getOpcode() == ARM::t2IT && !ITBlock.empty())
732       result = MCDisassembler::SoftFail;
733 
734     Check(result, AddThumbPredicate(MI));
735 
736     // If we find an IT instruction, we need to parse its condition
737     // code and mask operands so that we can apply them correctly
738     // to the subsequent instructions.
739     if (MI.getOpcode() == ARM::t2IT) {
740 
741       // (3 - the number of trailing zeros) is the number of then / else.
742       unsigned firstcond = MI.getOperand(0).getImm();
743       unsigned Mask = MI.getOperand(1).getImm();
744       unsigned CondBit0 = Mask >> 4 & 1;
745       unsigned NumTZ = CountTrailingZeros_32(Mask);
746       assert(NumTZ <= 3 && "Invalid IT mask!");
747       for (unsigned Pos = 3, e = NumTZ; Pos > e; --Pos) {
748         bool T = ((Mask >> Pos) & 1) == CondBit0;
749         if (T)
750           ITBlock.insert(ITBlock.begin(), firstcond);
751         else
752           ITBlock.insert(ITBlock.begin(), firstcond ^ 1);
753       }
754 
755       ITBlock.push_back(firstcond);
756     }
757 
758     return result;
759   }
760 
761   // We want to read exactly 4 bytes of data.
762   if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1) {
763     Size = 0;
764     return MCDisassembler::Fail;
765   }
766 
767   uint32_t insn32 = (bytes[3] <<  8) |
768                     (bytes[2] <<  0) |
769                     (bytes[1] << 24) |
770                     (bytes[0] << 16);
771   MI.clear();
772   result = decodeThumbInstruction32(MI, insn32, Address, this, STI);
773   if (result != MCDisassembler::Fail) {
774     Size = 4;
775     bool InITBlock = ITBlock.size();
776     Check(result, AddThumbPredicate(MI));
777     AddThumb1SBit(MI, InITBlock);
778     return result;
779   }
780 
781   MI.clear();
782   result = decodeThumb2Instruction32(MI, insn32, Address, this, STI);
783   if (result != MCDisassembler::Fail) {
784     Size = 4;
785     Check(result, AddThumbPredicate(MI));
786     return result;
787   }
788 
789   MI.clear();
790   result = decodeVFPInstruction32(MI, insn32, Address, this, STI);
791   if (result != MCDisassembler::Fail) {
792     Size = 4;
793     UpdateThumbVFPPredicate(MI);
794     return result;
795   }
796 
797   MI.clear();
798   result = decodeNEONDupInstruction32(MI, insn32, Address, this, STI);
799   if (result != MCDisassembler::Fail) {
800     Size = 4;
801     Check(result, AddThumbPredicate(MI));
802     return result;
803   }
804 
805   if (fieldFromInstruction32(insn32, 24, 8) == 0xF9) {
806     MI.clear();
807     uint32_t NEONLdStInsn = insn32;
808     NEONLdStInsn &= 0xF0FFFFFF;
809     NEONLdStInsn |= 0x04000000;
810     result = decodeNEONLoadStoreInstruction32(MI, NEONLdStInsn, Address, this, STI);
811     if (result != MCDisassembler::Fail) {
812       Size = 4;
813       Check(result, AddThumbPredicate(MI));
814       return result;
815     }
816   }
817 
818   if (fieldFromInstruction32(insn32, 24, 4) == 0xF) {
819     MI.clear();
820     uint32_t NEONDataInsn = insn32;
821     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
822     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
823     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
824     result = decodeNEONDataInstruction32(MI, NEONDataInsn, Address, this, STI);
825     if (result != MCDisassembler::Fail) {
826       Size = 4;
827       Check(result, AddThumbPredicate(MI));
828       return result;
829     }
830   }
831 
832   Size = 0;
833   return MCDisassembler::Fail;
834 }
835 
836 
837 extern "C" void LLVMInitializeARMDisassembler() {
838   TargetRegistry::RegisterMCDisassembler(TheARMTarget,
839                                          createARMDisassembler);
840   TargetRegistry::RegisterMCDisassembler(TheThumbTarget,
841                                          createThumbDisassembler);
842 }
843 
844 static const unsigned GPRDecoderTable[] = {
845   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
846   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
847   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
848   ARM::R12, ARM::SP, ARM::LR, ARM::PC
849 };
850 
851 static DecodeStatus DecodeGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
852                                    uint64_t Address, const void *Decoder) {
853   if (RegNo > 15)
854     return MCDisassembler::Fail;
855 
856   unsigned Register = GPRDecoderTable[RegNo];
857   Inst.addOperand(MCOperand::CreateReg(Register));
858   return MCDisassembler::Success;
859 }
860 
861 static DecodeStatus
862 DecodeGPRnopcRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
863                            uint64_t Address, const void *Decoder) {
864   if (RegNo == 15) return MCDisassembler::Fail;
865   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
866 }
867 
868 static DecodeStatus DecodetGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
869                                    uint64_t Address, const void *Decoder) {
870   if (RegNo > 7)
871     return MCDisassembler::Fail;
872   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
873 }
874 
875 static DecodeStatus DecodetcGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
876                                    uint64_t Address, const void *Decoder) {
877   unsigned Register = 0;
878   switch (RegNo) {
879     case 0:
880       Register = ARM::R0;
881       break;
882     case 1:
883       Register = ARM::R1;
884       break;
885     case 2:
886       Register = ARM::R2;
887       break;
888     case 3:
889       Register = ARM::R3;
890       break;
891     case 9:
892       Register = ARM::R9;
893       break;
894     case 12:
895       Register = ARM::R12;
896       break;
897     default:
898       return MCDisassembler::Fail;
899     }
900 
901   Inst.addOperand(MCOperand::CreateReg(Register));
902   return MCDisassembler::Success;
903 }
904 
905 static DecodeStatus DecoderGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
906                                    uint64_t Address, const void *Decoder) {
907   if (RegNo == 13 || RegNo == 15) return MCDisassembler::Fail;
908   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
909 }
910 
911 static const unsigned SPRDecoderTable[] = {
912      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
913      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
914      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
915     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
916     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
917     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
918     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
919     ARM::S28, ARM::S29, ARM::S30, ARM::S31
920 };
921 
922 static DecodeStatus DecodeSPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
923                                    uint64_t Address, const void *Decoder) {
924   if (RegNo > 31)
925     return MCDisassembler::Fail;
926 
927   unsigned Register = SPRDecoderTable[RegNo];
928   Inst.addOperand(MCOperand::CreateReg(Register));
929   return MCDisassembler::Success;
930 }
931 
932 static const unsigned DPRDecoderTable[] = {
933      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
934      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
935      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
936     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
937     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
938     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
939     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
940     ARM::D28, ARM::D29, ARM::D30, ARM::D31
941 };
942 
943 static DecodeStatus DecodeDPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
944                                    uint64_t Address, const void *Decoder) {
945   if (RegNo > 31)
946     return MCDisassembler::Fail;
947 
948   unsigned Register = DPRDecoderTable[RegNo];
949   Inst.addOperand(MCOperand::CreateReg(Register));
950   return MCDisassembler::Success;
951 }
952 
953 static DecodeStatus DecodeDPR_8RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
954                                    uint64_t Address, const void *Decoder) {
955   if (RegNo > 7)
956     return MCDisassembler::Fail;
957   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
958 }
959 
960 static DecodeStatus
961 DecodeDPR_VFP2RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
962                             uint64_t Address, const void *Decoder) {
963   if (RegNo > 15)
964     return MCDisassembler::Fail;
965   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
966 }
967 
968 static const unsigned QPRDecoderTable[] = {
969      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
970      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
971      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
972     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
973 };
974 
975 
976 static DecodeStatus DecodeQPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
977                                    uint64_t Address, const void *Decoder) {
978   if (RegNo > 31)
979     return MCDisassembler::Fail;
980   RegNo >>= 1;
981 
982   unsigned Register = QPRDecoderTable[RegNo];
983   Inst.addOperand(MCOperand::CreateReg(Register));
984   return MCDisassembler::Success;
985 }
986 
987 static DecodeStatus DecodePredicateOperand(llvm::MCInst &Inst, unsigned Val,
988                                uint64_t Address, const void *Decoder) {
989   if (Val == 0xF) return MCDisassembler::Fail;
990   // AL predicate is not allowed on Thumb1 branches.
991   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
992     return MCDisassembler::Fail;
993   Inst.addOperand(MCOperand::CreateImm(Val));
994   if (Val == ARMCC::AL) {
995     Inst.addOperand(MCOperand::CreateReg(0));
996   } else
997     Inst.addOperand(MCOperand::CreateReg(ARM::CPSR));
998   return MCDisassembler::Success;
999 }
1000 
1001 static DecodeStatus DecodeCCOutOperand(llvm::MCInst &Inst, unsigned Val,
1002                                uint64_t Address, const void *Decoder) {
1003   if (Val)
1004     Inst.addOperand(MCOperand::CreateReg(ARM::CPSR));
1005   else
1006     Inst.addOperand(MCOperand::CreateReg(0));
1007   return MCDisassembler::Success;
1008 }
1009 
1010 static DecodeStatus DecodeSOImmOperand(llvm::MCInst &Inst, unsigned Val,
1011                                uint64_t Address, const void *Decoder) {
1012   uint32_t imm = Val & 0xFF;
1013   uint32_t rot = (Val & 0xF00) >> 7;
1014   uint32_t rot_imm = (imm >> rot) | (imm << ((32-rot) & 0x1F));
1015   Inst.addOperand(MCOperand::CreateImm(rot_imm));
1016   return MCDisassembler::Success;
1017 }
1018 
1019 static DecodeStatus DecodeSORegImmOperand(llvm::MCInst &Inst, unsigned Val,
1020                                uint64_t Address, const void *Decoder) {
1021   DecodeStatus S = MCDisassembler::Success;
1022 
1023   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
1024   unsigned type = fieldFromInstruction32(Val, 5, 2);
1025   unsigned imm = fieldFromInstruction32(Val, 7, 5);
1026 
1027   // Register-immediate
1028   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1029     return MCDisassembler::Fail;
1030 
1031   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1032   switch (type) {
1033     case 0:
1034       Shift = ARM_AM::lsl;
1035       break;
1036     case 1:
1037       Shift = ARM_AM::lsr;
1038       break;
1039     case 2:
1040       Shift = ARM_AM::asr;
1041       break;
1042     case 3:
1043       Shift = ARM_AM::ror;
1044       break;
1045   }
1046 
1047   if (Shift == ARM_AM::ror && imm == 0)
1048     Shift = ARM_AM::rrx;
1049 
1050   unsigned Op = Shift | (imm << 3);
1051   Inst.addOperand(MCOperand::CreateImm(Op));
1052 
1053   return S;
1054 }
1055 
1056 static DecodeStatus DecodeSORegRegOperand(llvm::MCInst &Inst, unsigned Val,
1057                                uint64_t Address, const void *Decoder) {
1058   DecodeStatus S = MCDisassembler::Success;
1059 
1060   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
1061   unsigned type = fieldFromInstruction32(Val, 5, 2);
1062   unsigned Rs = fieldFromInstruction32(Val, 8, 4);
1063 
1064   // Register-register
1065   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1066     return MCDisassembler::Fail;
1067   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
1068     return MCDisassembler::Fail;
1069 
1070   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
1071   switch (type) {
1072     case 0:
1073       Shift = ARM_AM::lsl;
1074       break;
1075     case 1:
1076       Shift = ARM_AM::lsr;
1077       break;
1078     case 2:
1079       Shift = ARM_AM::asr;
1080       break;
1081     case 3:
1082       Shift = ARM_AM::ror;
1083       break;
1084   }
1085 
1086   Inst.addOperand(MCOperand::CreateImm(Shift));
1087 
1088   return S;
1089 }
1090 
1091 static DecodeStatus DecodeRegListOperand(llvm::MCInst &Inst, unsigned Val,
1092                                  uint64_t Address, const void *Decoder) {
1093   DecodeStatus S = MCDisassembler::Success;
1094 
1095   bool writebackLoad = false;
1096   unsigned writebackReg = 0;
1097   switch (Inst.getOpcode()) {
1098     default:
1099       break;
1100     case ARM::LDMIA_UPD:
1101     case ARM::LDMDB_UPD:
1102     case ARM::LDMIB_UPD:
1103     case ARM::LDMDA_UPD:
1104     case ARM::t2LDMIA_UPD:
1105     case ARM::t2LDMDB_UPD:
1106       writebackLoad = true;
1107       writebackReg = Inst.getOperand(0).getReg();
1108       break;
1109   }
1110 
1111   // Empty register lists are not allowed.
1112   if (CountPopulation_32(Val) == 0) return MCDisassembler::Fail;
1113   for (unsigned i = 0; i < 16; ++i) {
1114     if (Val & (1 << i)) {
1115       if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
1116         return MCDisassembler::Fail;
1117       // Writeback not allowed if Rn is in the target list.
1118       if (writebackLoad && writebackReg == Inst.end()[-1].getReg())
1119         Check(S, MCDisassembler::SoftFail);
1120     }
1121   }
1122 
1123   return S;
1124 }
1125 
1126 static DecodeStatus DecodeSPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
1127                                  uint64_t Address, const void *Decoder) {
1128   DecodeStatus S = MCDisassembler::Success;
1129 
1130   unsigned Vd = fieldFromInstruction32(Val, 8, 4);
1131   unsigned regs = Val & 0xFF;
1132 
1133   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
1134     return MCDisassembler::Fail;
1135   for (unsigned i = 0; i < (regs - 1); ++i) {
1136     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1137       return MCDisassembler::Fail;
1138   }
1139 
1140   return S;
1141 }
1142 
1143 static DecodeStatus DecodeDPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
1144                                  uint64_t Address, const void *Decoder) {
1145   DecodeStatus S = MCDisassembler::Success;
1146 
1147   unsigned Vd = fieldFromInstruction32(Val, 8, 4);
1148   unsigned regs = (Val & 0xFF) / 2;
1149 
1150   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
1151       return MCDisassembler::Fail;
1152   for (unsigned i = 0; i < (regs - 1); ++i) {
1153     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
1154       return MCDisassembler::Fail;
1155   }
1156 
1157   return S;
1158 }
1159 
1160 static DecodeStatus DecodeBitfieldMaskOperand(llvm::MCInst &Inst, unsigned Val,
1161                                       uint64_t Address, const void *Decoder) {
1162   // This operand encodes a mask of contiguous zeros between a specified MSB
1163   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1164   // the mask of all bits LSB-and-lower, and then xor them to create
1165   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1166   // create the final mask.
1167   unsigned msb = fieldFromInstruction32(Val, 5, 5);
1168   unsigned lsb = fieldFromInstruction32(Val, 0, 5);
1169 
1170   DecodeStatus S = MCDisassembler::Success;
1171   if (lsb > msb) Check(S, MCDisassembler::SoftFail);
1172 
1173   uint32_t msb_mask = 0xFFFFFFFF;
1174   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1175   uint32_t lsb_mask = (1U << lsb) - 1;
1176 
1177   Inst.addOperand(MCOperand::CreateImm(~(msb_mask ^ lsb_mask)));
1178   return S;
1179 }
1180 
1181 static DecodeStatus DecodeCopMemInstruction(llvm::MCInst &Inst, unsigned Insn,
1182                                   uint64_t Address, const void *Decoder) {
1183   DecodeStatus S = MCDisassembler::Success;
1184 
1185   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1186   unsigned CRd = fieldFromInstruction32(Insn, 12, 4);
1187   unsigned coproc = fieldFromInstruction32(Insn, 8, 4);
1188   unsigned imm = fieldFromInstruction32(Insn, 0, 8);
1189   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1190   unsigned U = fieldFromInstruction32(Insn, 23, 1);
1191 
1192   switch (Inst.getOpcode()) {
1193     case ARM::LDC_OFFSET:
1194     case ARM::LDC_PRE:
1195     case ARM::LDC_POST:
1196     case ARM::LDC_OPTION:
1197     case ARM::LDCL_OFFSET:
1198     case ARM::LDCL_PRE:
1199     case ARM::LDCL_POST:
1200     case ARM::LDCL_OPTION:
1201     case ARM::STC_OFFSET:
1202     case ARM::STC_PRE:
1203     case ARM::STC_POST:
1204     case ARM::STC_OPTION:
1205     case ARM::STCL_OFFSET:
1206     case ARM::STCL_PRE:
1207     case ARM::STCL_POST:
1208     case ARM::STCL_OPTION:
1209     case ARM::t2LDC_OFFSET:
1210     case ARM::t2LDC_PRE:
1211     case ARM::t2LDC_POST:
1212     case ARM::t2LDC_OPTION:
1213     case ARM::t2LDCL_OFFSET:
1214     case ARM::t2LDCL_PRE:
1215     case ARM::t2LDCL_POST:
1216     case ARM::t2LDCL_OPTION:
1217     case ARM::t2STC_OFFSET:
1218     case ARM::t2STC_PRE:
1219     case ARM::t2STC_POST:
1220     case ARM::t2STC_OPTION:
1221     case ARM::t2STCL_OFFSET:
1222     case ARM::t2STCL_PRE:
1223     case ARM::t2STCL_POST:
1224     case ARM::t2STCL_OPTION:
1225       if (coproc == 0xA || coproc == 0xB)
1226         return MCDisassembler::Fail;
1227       break;
1228     default:
1229       break;
1230   }
1231 
1232   Inst.addOperand(MCOperand::CreateImm(coproc));
1233   Inst.addOperand(MCOperand::CreateImm(CRd));
1234   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1235     return MCDisassembler::Fail;
1236 
1237   switch (Inst.getOpcode()) {
1238     case ARM::t2LDC2_OFFSET:
1239     case ARM::t2LDC2L_OFFSET:
1240     case ARM::t2LDC2_PRE:
1241     case ARM::t2LDC2L_PRE:
1242     case ARM::t2STC2_OFFSET:
1243     case ARM::t2STC2L_OFFSET:
1244     case ARM::t2STC2_PRE:
1245     case ARM::t2STC2L_PRE:
1246     case ARM::LDC2_OFFSET:
1247     case ARM::LDC2L_OFFSET:
1248     case ARM::LDC2_PRE:
1249     case ARM::LDC2L_PRE:
1250     case ARM::STC2_OFFSET:
1251     case ARM::STC2L_OFFSET:
1252     case ARM::STC2_PRE:
1253     case ARM::STC2L_PRE:
1254     case ARM::t2LDC_OFFSET:
1255     case ARM::t2LDCL_OFFSET:
1256     case ARM::t2LDC_PRE:
1257     case ARM::t2LDCL_PRE:
1258     case ARM::t2STC_OFFSET:
1259     case ARM::t2STCL_OFFSET:
1260     case ARM::t2STC_PRE:
1261     case ARM::t2STCL_PRE:
1262     case ARM::LDC_OFFSET:
1263     case ARM::LDCL_OFFSET:
1264     case ARM::LDC_PRE:
1265     case ARM::LDCL_PRE:
1266     case ARM::STC_OFFSET:
1267     case ARM::STCL_OFFSET:
1268     case ARM::STC_PRE:
1269     case ARM::STCL_PRE:
1270       imm = ARM_AM::getAM5Opc(U ? ARM_AM::add : ARM_AM::sub, imm);
1271       Inst.addOperand(MCOperand::CreateImm(imm));
1272       break;
1273     case ARM::t2LDC2_POST:
1274     case ARM::t2LDC2L_POST:
1275     case ARM::t2STC2_POST:
1276     case ARM::t2STC2L_POST:
1277     case ARM::LDC2_POST:
1278     case ARM::LDC2L_POST:
1279     case ARM::STC2_POST:
1280     case ARM::STC2L_POST:
1281     case ARM::t2LDC_POST:
1282     case ARM::t2LDCL_POST:
1283     case ARM::t2STC_POST:
1284     case ARM::t2STCL_POST:
1285     case ARM::LDC_POST:
1286     case ARM::LDCL_POST:
1287     case ARM::STC_POST:
1288     case ARM::STCL_POST:
1289       imm |= U << 8;
1290       // fall through.
1291     default:
1292       // The 'option' variant doesn't encode 'U' in the immediate since
1293       // the immediate is unsigned [0,255].
1294       Inst.addOperand(MCOperand::CreateImm(imm));
1295       break;
1296   }
1297 
1298   switch (Inst.getOpcode()) {
1299     case ARM::LDC_OFFSET:
1300     case ARM::LDC_PRE:
1301     case ARM::LDC_POST:
1302     case ARM::LDC_OPTION:
1303     case ARM::LDCL_OFFSET:
1304     case ARM::LDCL_PRE:
1305     case ARM::LDCL_POST:
1306     case ARM::LDCL_OPTION:
1307     case ARM::STC_OFFSET:
1308     case ARM::STC_PRE:
1309     case ARM::STC_POST:
1310     case ARM::STC_OPTION:
1311     case ARM::STCL_OFFSET:
1312     case ARM::STCL_PRE:
1313     case ARM::STCL_POST:
1314     case ARM::STCL_OPTION:
1315       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1316         return MCDisassembler::Fail;
1317       break;
1318     default:
1319       break;
1320   }
1321 
1322   return S;
1323 }
1324 
1325 static DecodeStatus
1326 DecodeAddrMode2IdxInstruction(llvm::MCInst &Inst, unsigned Insn,
1327                               uint64_t Address, const void *Decoder) {
1328   DecodeStatus S = MCDisassembler::Success;
1329 
1330   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1331   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
1332   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1333   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
1334   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1335   unsigned reg = fieldFromInstruction32(Insn, 25, 1);
1336   unsigned P = fieldFromInstruction32(Insn, 24, 1);
1337   unsigned W = fieldFromInstruction32(Insn, 21, 1);
1338 
1339   // On stores, the writeback operand precedes Rt.
1340   switch (Inst.getOpcode()) {
1341     case ARM::STR_POST_IMM:
1342     case ARM::STR_POST_REG:
1343     case ARM::STRB_POST_IMM:
1344     case ARM::STRB_POST_REG:
1345     case ARM::STRT_POST_REG:
1346     case ARM::STRT_POST_IMM:
1347     case ARM::STRBT_POST_REG:
1348     case ARM::STRBT_POST_IMM:
1349       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1350         return MCDisassembler::Fail;
1351       break;
1352     default:
1353       break;
1354   }
1355 
1356   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1357     return MCDisassembler::Fail;
1358 
1359   // On loads, the writeback operand comes after Rt.
1360   switch (Inst.getOpcode()) {
1361     case ARM::LDR_POST_IMM:
1362     case ARM::LDR_POST_REG:
1363     case ARM::LDRB_POST_IMM:
1364     case ARM::LDRB_POST_REG:
1365     case ARM::LDRBT_POST_REG:
1366     case ARM::LDRBT_POST_IMM:
1367     case ARM::LDRT_POST_REG:
1368     case ARM::LDRT_POST_IMM:
1369       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1370         return MCDisassembler::Fail;
1371       break;
1372     default:
1373       break;
1374   }
1375 
1376   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1377     return MCDisassembler::Fail;
1378 
1379   ARM_AM::AddrOpc Op = ARM_AM::add;
1380   if (!fieldFromInstruction32(Insn, 23, 1))
1381     Op = ARM_AM::sub;
1382 
1383   bool writeback = (P == 0) || (W == 1);
1384   unsigned idx_mode = 0;
1385   if (P && writeback)
1386     idx_mode = ARMII::IndexModePre;
1387   else if (!P && writeback)
1388     idx_mode = ARMII::IndexModePost;
1389 
1390   if (writeback && (Rn == 15 || Rn == Rt))
1391     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1392 
1393   if (reg) {
1394     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1395       return MCDisassembler::Fail;
1396     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1397     switch( fieldFromInstruction32(Insn, 5, 2)) {
1398       case 0:
1399         Opc = ARM_AM::lsl;
1400         break;
1401       case 1:
1402         Opc = ARM_AM::lsr;
1403         break;
1404       case 2:
1405         Opc = ARM_AM::asr;
1406         break;
1407       case 3:
1408         Opc = ARM_AM::ror;
1409         break;
1410       default:
1411         return MCDisassembler::Fail;
1412     }
1413     unsigned amt = fieldFromInstruction32(Insn, 7, 5);
1414     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1415 
1416     Inst.addOperand(MCOperand::CreateImm(imm));
1417   } else {
1418     Inst.addOperand(MCOperand::CreateReg(0));
1419     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1420     Inst.addOperand(MCOperand::CreateImm(tmp));
1421   }
1422 
1423   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1424     return MCDisassembler::Fail;
1425 
1426   return S;
1427 }
1428 
1429 static DecodeStatus DecodeSORegMemOperand(llvm::MCInst &Inst, unsigned Val,
1430                                   uint64_t Address, const void *Decoder) {
1431   DecodeStatus S = MCDisassembler::Success;
1432 
1433   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
1434   unsigned Rm = fieldFromInstruction32(Val,  0, 4);
1435   unsigned type = fieldFromInstruction32(Val, 5, 2);
1436   unsigned imm = fieldFromInstruction32(Val, 7, 5);
1437   unsigned U = fieldFromInstruction32(Val, 12, 1);
1438 
1439   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1440   switch (type) {
1441     case 0:
1442       ShOp = ARM_AM::lsl;
1443       break;
1444     case 1:
1445       ShOp = ARM_AM::lsr;
1446       break;
1447     case 2:
1448       ShOp = ARM_AM::asr;
1449       break;
1450     case 3:
1451       ShOp = ARM_AM::ror;
1452       break;
1453   }
1454 
1455   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1456     return MCDisassembler::Fail;
1457   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1458     return MCDisassembler::Fail;
1459   unsigned shift;
1460   if (U)
1461     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1462   else
1463     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1464   Inst.addOperand(MCOperand::CreateImm(shift));
1465 
1466   return S;
1467 }
1468 
1469 static DecodeStatus
1470 DecodeAddrMode3Instruction(llvm::MCInst &Inst, unsigned Insn,
1471                            uint64_t Address, const void *Decoder) {
1472   DecodeStatus S = MCDisassembler::Success;
1473 
1474   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
1475   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1476   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1477   unsigned type = fieldFromInstruction32(Insn, 22, 1);
1478   unsigned imm = fieldFromInstruction32(Insn, 8, 4);
1479   unsigned U = ((~fieldFromInstruction32(Insn, 23, 1)) & 1) << 8;
1480   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1481   unsigned W = fieldFromInstruction32(Insn, 21, 1);
1482   unsigned P = fieldFromInstruction32(Insn, 24, 1);
1483 
1484   bool writeback = (W == 1) | (P == 0);
1485 
1486   // For {LD,ST}RD, Rt must be even, else undefined.
1487   switch (Inst.getOpcode()) {
1488     case ARM::STRD:
1489     case ARM::STRD_PRE:
1490     case ARM::STRD_POST:
1491     case ARM::LDRD:
1492     case ARM::LDRD_PRE:
1493     case ARM::LDRD_POST:
1494       if (Rt & 0x1) return MCDisassembler::Fail;
1495       break;
1496     default:
1497       break;
1498   }
1499 
1500   if (writeback) { // Writeback
1501     if (P)
1502       U |= ARMII::IndexModePre << 9;
1503     else
1504       U |= ARMII::IndexModePost << 9;
1505 
1506     // On stores, the writeback operand precedes Rt.
1507     switch (Inst.getOpcode()) {
1508     case ARM::STRD:
1509     case ARM::STRD_PRE:
1510     case ARM::STRD_POST:
1511     case ARM::STRH:
1512     case ARM::STRH_PRE:
1513     case ARM::STRH_POST:
1514       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1515         return MCDisassembler::Fail;
1516       break;
1517     default:
1518       break;
1519     }
1520   }
1521 
1522   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1523     return MCDisassembler::Fail;
1524   switch (Inst.getOpcode()) {
1525     case ARM::STRD:
1526     case ARM::STRD_PRE:
1527     case ARM::STRD_POST:
1528     case ARM::LDRD:
1529     case ARM::LDRD_PRE:
1530     case ARM::LDRD_POST:
1531       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
1532         return MCDisassembler::Fail;
1533       break;
1534     default:
1535       break;
1536   }
1537 
1538   if (writeback) {
1539     // On loads, the writeback operand comes after Rt.
1540     switch (Inst.getOpcode()) {
1541     case ARM::LDRD:
1542     case ARM::LDRD_PRE:
1543     case ARM::LDRD_POST:
1544     case ARM::LDRH:
1545     case ARM::LDRH_PRE:
1546     case ARM::LDRH_POST:
1547     case ARM::LDRSH:
1548     case ARM::LDRSH_PRE:
1549     case ARM::LDRSH_POST:
1550     case ARM::LDRSB:
1551     case ARM::LDRSB_PRE:
1552     case ARM::LDRSB_POST:
1553     case ARM::LDRHTr:
1554     case ARM::LDRSBTr:
1555       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1556         return MCDisassembler::Fail;
1557       break;
1558     default:
1559       break;
1560     }
1561   }
1562 
1563   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1564     return MCDisassembler::Fail;
1565 
1566   if (type) {
1567     Inst.addOperand(MCOperand::CreateReg(0));
1568     Inst.addOperand(MCOperand::CreateImm(U | (imm << 4) | Rm));
1569   } else {
1570     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1571     return MCDisassembler::Fail;
1572     Inst.addOperand(MCOperand::CreateImm(U));
1573   }
1574 
1575   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1576     return MCDisassembler::Fail;
1577 
1578   return S;
1579 }
1580 
1581 static DecodeStatus DecodeRFEInstruction(llvm::MCInst &Inst, unsigned Insn,
1582                                  uint64_t Address, const void *Decoder) {
1583   DecodeStatus S = MCDisassembler::Success;
1584 
1585   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1586   unsigned mode = fieldFromInstruction32(Insn, 23, 2);
1587 
1588   switch (mode) {
1589     case 0:
1590       mode = ARM_AM::da;
1591       break;
1592     case 1:
1593       mode = ARM_AM::ia;
1594       break;
1595     case 2:
1596       mode = ARM_AM::db;
1597       break;
1598     case 3:
1599       mode = ARM_AM::ib;
1600       break;
1601   }
1602 
1603   Inst.addOperand(MCOperand::CreateImm(mode));
1604   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1605     return MCDisassembler::Fail;
1606 
1607   return S;
1608 }
1609 
1610 static DecodeStatus DecodeMemMultipleWritebackInstruction(llvm::MCInst &Inst,
1611                                   unsigned Insn,
1612                                   uint64_t Address, const void *Decoder) {
1613   DecodeStatus S = MCDisassembler::Success;
1614 
1615   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1616   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1617   unsigned reglist = fieldFromInstruction32(Insn, 0, 16);
1618 
1619   if (pred == 0xF) {
1620     switch (Inst.getOpcode()) {
1621       case ARM::LDMDA:
1622         Inst.setOpcode(ARM::RFEDA);
1623         break;
1624       case ARM::LDMDA_UPD:
1625         Inst.setOpcode(ARM::RFEDA_UPD);
1626         break;
1627       case ARM::LDMDB:
1628         Inst.setOpcode(ARM::RFEDB);
1629         break;
1630       case ARM::LDMDB_UPD:
1631         Inst.setOpcode(ARM::RFEDB_UPD);
1632         break;
1633       case ARM::LDMIA:
1634         Inst.setOpcode(ARM::RFEIA);
1635         break;
1636       case ARM::LDMIA_UPD:
1637         Inst.setOpcode(ARM::RFEIA_UPD);
1638         break;
1639       case ARM::LDMIB:
1640         Inst.setOpcode(ARM::RFEIB);
1641         break;
1642       case ARM::LDMIB_UPD:
1643         Inst.setOpcode(ARM::RFEIB_UPD);
1644         break;
1645       case ARM::STMDA:
1646         Inst.setOpcode(ARM::SRSDA);
1647         break;
1648       case ARM::STMDA_UPD:
1649         Inst.setOpcode(ARM::SRSDA_UPD);
1650         break;
1651       case ARM::STMDB:
1652         Inst.setOpcode(ARM::SRSDB);
1653         break;
1654       case ARM::STMDB_UPD:
1655         Inst.setOpcode(ARM::SRSDB_UPD);
1656         break;
1657       case ARM::STMIA:
1658         Inst.setOpcode(ARM::SRSIA);
1659         break;
1660       case ARM::STMIA_UPD:
1661         Inst.setOpcode(ARM::SRSIA_UPD);
1662         break;
1663       case ARM::STMIB:
1664         Inst.setOpcode(ARM::SRSIB);
1665         break;
1666       case ARM::STMIB_UPD:
1667         Inst.setOpcode(ARM::SRSIB_UPD);
1668         break;
1669       default:
1670         if (!Check(S, MCDisassembler::Fail)) return MCDisassembler::Fail;
1671     }
1672 
1673     // For stores (which become SRS's, the only operand is the mode.
1674     if (fieldFromInstruction32(Insn, 20, 1) == 0) {
1675       Inst.addOperand(
1676           MCOperand::CreateImm(fieldFromInstruction32(Insn, 0, 4)));
1677       return S;
1678     }
1679 
1680     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
1681   }
1682 
1683   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1684     return MCDisassembler::Fail;
1685   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1686     return MCDisassembler::Fail; // Tied
1687   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1688     return MCDisassembler::Fail;
1689   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
1690     return MCDisassembler::Fail;
1691 
1692   return S;
1693 }
1694 
1695 static DecodeStatus DecodeCPSInstruction(llvm::MCInst &Inst, unsigned Insn,
1696                                  uint64_t Address, const void *Decoder) {
1697   unsigned imod = fieldFromInstruction32(Insn, 18, 2);
1698   unsigned M = fieldFromInstruction32(Insn, 17, 1);
1699   unsigned iflags = fieldFromInstruction32(Insn, 6, 3);
1700   unsigned mode = fieldFromInstruction32(Insn, 0, 5);
1701 
1702   DecodeStatus S = MCDisassembler::Success;
1703 
1704   // imod == '01' --> UNPREDICTABLE
1705   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
1706   // return failure here.  The '01' imod value is unprintable, so there's
1707   // nothing useful we could do even if we returned UNPREDICTABLE.
1708 
1709   if (imod == 1) return MCDisassembler::Fail;
1710 
1711   if (imod && M) {
1712     Inst.setOpcode(ARM::CPS3p);
1713     Inst.addOperand(MCOperand::CreateImm(imod));
1714     Inst.addOperand(MCOperand::CreateImm(iflags));
1715     Inst.addOperand(MCOperand::CreateImm(mode));
1716   } else if (imod && !M) {
1717     Inst.setOpcode(ARM::CPS2p);
1718     Inst.addOperand(MCOperand::CreateImm(imod));
1719     Inst.addOperand(MCOperand::CreateImm(iflags));
1720     if (mode) S = MCDisassembler::SoftFail;
1721   } else if (!imod && M) {
1722     Inst.setOpcode(ARM::CPS1p);
1723     Inst.addOperand(MCOperand::CreateImm(mode));
1724     if (iflags) S = MCDisassembler::SoftFail;
1725   } else {
1726     // imod == '00' && M == '0' --> UNPREDICTABLE
1727     Inst.setOpcode(ARM::CPS1p);
1728     Inst.addOperand(MCOperand::CreateImm(mode));
1729     S = MCDisassembler::SoftFail;
1730   }
1731 
1732   return S;
1733 }
1734 
1735 static DecodeStatus DecodeT2CPSInstruction(llvm::MCInst &Inst, unsigned Insn,
1736                                  uint64_t Address, const void *Decoder) {
1737   unsigned imod = fieldFromInstruction32(Insn, 9, 2);
1738   unsigned M = fieldFromInstruction32(Insn, 8, 1);
1739   unsigned iflags = fieldFromInstruction32(Insn, 5, 3);
1740   unsigned mode = fieldFromInstruction32(Insn, 0, 5);
1741 
1742   DecodeStatus S = MCDisassembler::Success;
1743 
1744   // imod == '01' --> UNPREDICTABLE
1745   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
1746   // return failure here.  The '01' imod value is unprintable, so there's
1747   // nothing useful we could do even if we returned UNPREDICTABLE.
1748 
1749   if (imod == 1) return MCDisassembler::Fail;
1750 
1751   if (imod && M) {
1752     Inst.setOpcode(ARM::t2CPS3p);
1753     Inst.addOperand(MCOperand::CreateImm(imod));
1754     Inst.addOperand(MCOperand::CreateImm(iflags));
1755     Inst.addOperand(MCOperand::CreateImm(mode));
1756   } else if (imod && !M) {
1757     Inst.setOpcode(ARM::t2CPS2p);
1758     Inst.addOperand(MCOperand::CreateImm(imod));
1759     Inst.addOperand(MCOperand::CreateImm(iflags));
1760     if (mode) S = MCDisassembler::SoftFail;
1761   } else if (!imod && M) {
1762     Inst.setOpcode(ARM::t2CPS1p);
1763     Inst.addOperand(MCOperand::CreateImm(mode));
1764     if (iflags) S = MCDisassembler::SoftFail;
1765   } else {
1766     // imod == '00' && M == '0' --> UNPREDICTABLE
1767     Inst.setOpcode(ARM::t2CPS1p);
1768     Inst.addOperand(MCOperand::CreateImm(mode));
1769     S = MCDisassembler::SoftFail;
1770   }
1771 
1772   return S;
1773 }
1774 
1775 static DecodeStatus DecodeT2MOVTWInstruction(llvm::MCInst &Inst, unsigned Insn,
1776                                  uint64_t Address, const void *Decoder) {
1777   DecodeStatus S = MCDisassembler::Success;
1778 
1779   unsigned Rd = fieldFromInstruction32(Insn, 8, 4);
1780   unsigned imm = 0;
1781 
1782   imm |= (fieldFromInstruction32(Insn, 0, 8) << 0);
1783   imm |= (fieldFromInstruction32(Insn, 12, 3) << 8);
1784   imm |= (fieldFromInstruction32(Insn, 16, 4) << 12);
1785   imm |= (fieldFromInstruction32(Insn, 26, 1) << 11);
1786 
1787   if (Inst.getOpcode() == ARM::t2MOVTi16)
1788     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
1789       return MCDisassembler::Fail;
1790   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
1791     return MCDisassembler::Fail;
1792 
1793   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
1794     Inst.addOperand(MCOperand::CreateImm(imm));
1795 
1796   return S;
1797 }
1798 
1799 static DecodeStatus DecodeArmMOVTWInstruction(llvm::MCInst &Inst, unsigned Insn,
1800                                  uint64_t Address, const void *Decoder) {
1801   DecodeStatus S = MCDisassembler::Success;
1802 
1803   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1804   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1805   unsigned imm = 0;
1806 
1807   imm |= (fieldFromInstruction32(Insn, 0, 12) << 0);
1808   imm |= (fieldFromInstruction32(Insn, 16, 4) << 12);
1809 
1810   if (Inst.getOpcode() == ARM::MOVTi16)
1811     if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
1812       return MCDisassembler::Fail;
1813   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
1814     return MCDisassembler::Fail;
1815 
1816   if (!tryAddingSymbolicOperand(Address, imm, false, 4, Inst, Decoder))
1817     Inst.addOperand(MCOperand::CreateImm(imm));
1818 
1819   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1820     return MCDisassembler::Fail;
1821 
1822   return S;
1823 }
1824 
1825 static DecodeStatus DecodeSMLAInstruction(llvm::MCInst &Inst, unsigned Insn,
1826                                  uint64_t Address, const void *Decoder) {
1827   DecodeStatus S = MCDisassembler::Success;
1828 
1829   unsigned Rd = fieldFromInstruction32(Insn, 16, 4);
1830   unsigned Rn = fieldFromInstruction32(Insn, 0, 4);
1831   unsigned Rm = fieldFromInstruction32(Insn, 8, 4);
1832   unsigned Ra = fieldFromInstruction32(Insn, 12, 4);
1833   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1834 
1835   if (pred == 0xF)
1836     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
1837 
1838   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
1839     return MCDisassembler::Fail;
1840   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
1841     return MCDisassembler::Fail;
1842   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1843     return MCDisassembler::Fail;
1844   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
1845     return MCDisassembler::Fail;
1846 
1847   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1848     return MCDisassembler::Fail;
1849 
1850   return S;
1851 }
1852 
1853 static DecodeStatus DecodeAddrModeImm12Operand(llvm::MCInst &Inst, unsigned Val,
1854                            uint64_t Address, const void *Decoder) {
1855   DecodeStatus S = MCDisassembler::Success;
1856 
1857   unsigned add = fieldFromInstruction32(Val, 12, 1);
1858   unsigned imm = fieldFromInstruction32(Val, 0, 12);
1859   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
1860 
1861   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1862     return MCDisassembler::Fail;
1863 
1864   if (!add) imm *= -1;
1865   if (imm == 0 && !add) imm = INT32_MIN;
1866   Inst.addOperand(MCOperand::CreateImm(imm));
1867   if (Rn == 15)
1868     tryAddingPcLoadReferenceComment(Address, Address + imm + 8, Decoder);
1869 
1870   return S;
1871 }
1872 
1873 static DecodeStatus DecodeAddrMode5Operand(llvm::MCInst &Inst, unsigned Val,
1874                                    uint64_t Address, const void *Decoder) {
1875   DecodeStatus S = MCDisassembler::Success;
1876 
1877   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
1878   unsigned U = fieldFromInstruction32(Val, 8, 1);
1879   unsigned imm = fieldFromInstruction32(Val, 0, 8);
1880 
1881   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1882     return MCDisassembler::Fail;
1883 
1884   if (U)
1885     Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
1886   else
1887     Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
1888 
1889   return S;
1890 }
1891 
1892 static DecodeStatus DecodeAddrMode7Operand(llvm::MCInst &Inst, unsigned Val,
1893                                    uint64_t Address, const void *Decoder) {
1894   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
1895 }
1896 
1897 static DecodeStatus
1898 DecodeBranchImmInstruction(llvm::MCInst &Inst, unsigned Insn,
1899                            uint64_t Address, const void *Decoder) {
1900   DecodeStatus S = MCDisassembler::Success;
1901 
1902   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1903   unsigned imm = fieldFromInstruction32(Insn, 0, 24) << 2;
1904 
1905   if (pred == 0xF) {
1906     Inst.setOpcode(ARM::BLXi);
1907     imm |= fieldFromInstruction32(Insn, 24, 1) << 1;
1908     Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1909     return S;
1910   }
1911 
1912   if (!tryAddingSymbolicOperand(Address, Address + SignExtend32<26>(imm) + 8, true,
1913                                 4, Inst, Decoder))
1914     Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1915   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1916     return MCDisassembler::Fail;
1917 
1918   return S;
1919 }
1920 
1921 
1922 static DecodeStatus DecodeVCVTImmOperand(llvm::MCInst &Inst, unsigned Val,
1923                                  uint64_t Address, const void *Decoder) {
1924   Inst.addOperand(MCOperand::CreateImm(64 - Val));
1925   return MCDisassembler::Success;
1926 }
1927 
1928 static DecodeStatus DecodeAddrMode6Operand(llvm::MCInst &Inst, unsigned Val,
1929                                    uint64_t Address, const void *Decoder) {
1930   DecodeStatus S = MCDisassembler::Success;
1931 
1932   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
1933   unsigned align = fieldFromInstruction32(Val, 4, 2);
1934 
1935   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1936     return MCDisassembler::Fail;
1937   if (!align)
1938     Inst.addOperand(MCOperand::CreateImm(0));
1939   else
1940     Inst.addOperand(MCOperand::CreateImm(4 << align));
1941 
1942   return S;
1943 }
1944 
1945 static DecodeStatus DecodeVLDInstruction(llvm::MCInst &Inst, unsigned Insn,
1946                                    uint64_t Address, const void *Decoder) {
1947   DecodeStatus S = MCDisassembler::Success;
1948 
1949   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1950   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1951   unsigned wb = fieldFromInstruction32(Insn, 16, 4);
1952   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1953   Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
1954   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1955 
1956   // First output register
1957   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
1958     return MCDisassembler::Fail;
1959 
1960   // Second output register
1961   switch (Inst.getOpcode()) {
1962     case ARM::VLD1d8T:
1963     case ARM::VLD1d16T:
1964     case ARM::VLD1d32T:
1965     case ARM::VLD1d64T:
1966     case ARM::VLD1d8T_UPD:
1967     case ARM::VLD1d16T_UPD:
1968     case ARM::VLD1d32T_UPD:
1969     case ARM::VLD1d64T_UPD:
1970     case ARM::VLD1d8Q:
1971     case ARM::VLD1d16Q:
1972     case ARM::VLD1d32Q:
1973     case ARM::VLD1d64Q:
1974     case ARM::VLD1d8Q_UPD:
1975     case ARM::VLD1d16Q_UPD:
1976     case ARM::VLD1d32Q_UPD:
1977     case ARM::VLD1d64Q_UPD:
1978     case ARM::VLD2d8:
1979     case ARM::VLD2d16:
1980     case ARM::VLD2d32:
1981     case ARM::VLD2d8_UPD:
1982     case ARM::VLD2d16_UPD:
1983     case ARM::VLD2d32_UPD:
1984     case ARM::VLD2q8:
1985     case ARM::VLD2q16:
1986     case ARM::VLD2q32:
1987     case ARM::VLD2q8_UPD:
1988     case ARM::VLD2q16_UPD:
1989     case ARM::VLD2q32_UPD:
1990     case ARM::VLD3d8:
1991     case ARM::VLD3d16:
1992     case ARM::VLD3d32:
1993     case ARM::VLD3d8_UPD:
1994     case ARM::VLD3d16_UPD:
1995     case ARM::VLD3d32_UPD:
1996     case ARM::VLD4d8:
1997     case ARM::VLD4d16:
1998     case ARM::VLD4d32:
1999     case ARM::VLD4d8_UPD:
2000     case ARM::VLD4d16_UPD:
2001     case ARM::VLD4d32_UPD:
2002       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2003         return MCDisassembler::Fail;
2004       break;
2005     case ARM::VLD2b8:
2006     case ARM::VLD2b16:
2007     case ARM::VLD2b32:
2008     case ARM::VLD2b8_UPD:
2009     case ARM::VLD2b16_UPD:
2010     case ARM::VLD2b32_UPD:
2011     case ARM::VLD3q8:
2012     case ARM::VLD3q16:
2013     case ARM::VLD3q32:
2014     case ARM::VLD3q8_UPD:
2015     case ARM::VLD3q16_UPD:
2016     case ARM::VLD3q32_UPD:
2017     case ARM::VLD4q8:
2018     case ARM::VLD4q16:
2019     case ARM::VLD4q32:
2020     case ARM::VLD4q8_UPD:
2021     case ARM::VLD4q16_UPD:
2022     case ARM::VLD4q32_UPD:
2023       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2024         return MCDisassembler::Fail;
2025     default:
2026       break;
2027   }
2028 
2029   // Third output register
2030   switch(Inst.getOpcode()) {
2031     case ARM::VLD1d8T:
2032     case ARM::VLD1d16T:
2033     case ARM::VLD1d32T:
2034     case ARM::VLD1d64T:
2035     case ARM::VLD1d8T_UPD:
2036     case ARM::VLD1d16T_UPD:
2037     case ARM::VLD1d32T_UPD:
2038     case ARM::VLD1d64T_UPD:
2039     case ARM::VLD1d8Q:
2040     case ARM::VLD1d16Q:
2041     case ARM::VLD1d32Q:
2042     case ARM::VLD1d64Q:
2043     case ARM::VLD1d8Q_UPD:
2044     case ARM::VLD1d16Q_UPD:
2045     case ARM::VLD1d32Q_UPD:
2046     case ARM::VLD1d64Q_UPD:
2047     case ARM::VLD2q8:
2048     case ARM::VLD2q16:
2049     case ARM::VLD2q32:
2050     case ARM::VLD2q8_UPD:
2051     case ARM::VLD2q16_UPD:
2052     case ARM::VLD2q32_UPD:
2053     case ARM::VLD3d8:
2054     case ARM::VLD3d16:
2055     case ARM::VLD3d32:
2056     case ARM::VLD3d8_UPD:
2057     case ARM::VLD3d16_UPD:
2058     case ARM::VLD3d32_UPD:
2059     case ARM::VLD4d8:
2060     case ARM::VLD4d16:
2061     case ARM::VLD4d32:
2062     case ARM::VLD4d8_UPD:
2063     case ARM::VLD4d16_UPD:
2064     case ARM::VLD4d32_UPD:
2065       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2066         return MCDisassembler::Fail;
2067       break;
2068     case ARM::VLD3q8:
2069     case ARM::VLD3q16:
2070     case ARM::VLD3q32:
2071     case ARM::VLD3q8_UPD:
2072     case ARM::VLD3q16_UPD:
2073     case ARM::VLD3q32_UPD:
2074     case ARM::VLD4q8:
2075     case ARM::VLD4q16:
2076     case ARM::VLD4q32:
2077     case ARM::VLD4q8_UPD:
2078     case ARM::VLD4q16_UPD:
2079     case ARM::VLD4q32_UPD:
2080       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2081         return MCDisassembler::Fail;
2082       break;
2083     default:
2084       break;
2085   }
2086 
2087   // Fourth output register
2088   switch (Inst.getOpcode()) {
2089     case ARM::VLD1d8Q:
2090     case ARM::VLD1d16Q:
2091     case ARM::VLD1d32Q:
2092     case ARM::VLD1d64Q:
2093     case ARM::VLD1d8Q_UPD:
2094     case ARM::VLD1d16Q_UPD:
2095     case ARM::VLD1d32Q_UPD:
2096     case ARM::VLD1d64Q_UPD:
2097     case ARM::VLD2q8:
2098     case ARM::VLD2q16:
2099     case ARM::VLD2q32:
2100     case ARM::VLD2q8_UPD:
2101     case ARM::VLD2q16_UPD:
2102     case ARM::VLD2q32_UPD:
2103     case ARM::VLD4d8:
2104     case ARM::VLD4d16:
2105     case ARM::VLD4d32:
2106     case ARM::VLD4d8_UPD:
2107     case ARM::VLD4d16_UPD:
2108     case ARM::VLD4d32_UPD:
2109       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2110         return MCDisassembler::Fail;
2111       break;
2112     case ARM::VLD4q8:
2113     case ARM::VLD4q16:
2114     case ARM::VLD4q32:
2115     case ARM::VLD4q8_UPD:
2116     case ARM::VLD4q16_UPD:
2117     case ARM::VLD4q32_UPD:
2118       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2119         return MCDisassembler::Fail;
2120       break;
2121     default:
2122       break;
2123   }
2124 
2125   // Writeback operand
2126   switch (Inst.getOpcode()) {
2127     case ARM::VLD1d8_UPD:
2128     case ARM::VLD1d16_UPD:
2129     case ARM::VLD1d32_UPD:
2130     case ARM::VLD1d64_UPD:
2131     case ARM::VLD1q8_UPD:
2132     case ARM::VLD1q16_UPD:
2133     case ARM::VLD1q32_UPD:
2134     case ARM::VLD1q64_UPD:
2135     case ARM::VLD1d8T_UPD:
2136     case ARM::VLD1d16T_UPD:
2137     case ARM::VLD1d32T_UPD:
2138     case ARM::VLD1d64T_UPD:
2139     case ARM::VLD1d8Q_UPD:
2140     case ARM::VLD1d16Q_UPD:
2141     case ARM::VLD1d32Q_UPD:
2142     case ARM::VLD1d64Q_UPD:
2143     case ARM::VLD2d8_UPD:
2144     case ARM::VLD2d16_UPD:
2145     case ARM::VLD2d32_UPD:
2146     case ARM::VLD2q8_UPD:
2147     case ARM::VLD2q16_UPD:
2148     case ARM::VLD2q32_UPD:
2149     case ARM::VLD2b8_UPD:
2150     case ARM::VLD2b16_UPD:
2151     case ARM::VLD2b32_UPD:
2152     case ARM::VLD3d8_UPD:
2153     case ARM::VLD3d16_UPD:
2154     case ARM::VLD3d32_UPD:
2155     case ARM::VLD3q8_UPD:
2156     case ARM::VLD3q16_UPD:
2157     case ARM::VLD3q32_UPD:
2158     case ARM::VLD4d8_UPD:
2159     case ARM::VLD4d16_UPD:
2160     case ARM::VLD4d32_UPD:
2161     case ARM::VLD4q8_UPD:
2162     case ARM::VLD4q16_UPD:
2163     case ARM::VLD4q32_UPD:
2164       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2165         return MCDisassembler::Fail;
2166       break;
2167     default:
2168       break;
2169   }
2170 
2171   // AddrMode6 Base (register+alignment)
2172   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2173     return MCDisassembler::Fail;
2174 
2175   // AddrMode6 Offset (register)
2176   if (Rm == 0xD)
2177     Inst.addOperand(MCOperand::CreateReg(0));
2178   else if (Rm != 0xF) {
2179     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2180       return MCDisassembler::Fail;
2181   }
2182 
2183   return S;
2184 }
2185 
2186 static DecodeStatus DecodeVSTInstruction(llvm::MCInst &Inst, unsigned Insn,
2187                                  uint64_t Address, const void *Decoder) {
2188   DecodeStatus S = MCDisassembler::Success;
2189 
2190   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2191   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2192   unsigned wb = fieldFromInstruction32(Insn, 16, 4);
2193   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2194   Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
2195   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2196 
2197   // Writeback Operand
2198   switch (Inst.getOpcode()) {
2199     case ARM::VST1d8_UPD:
2200     case ARM::VST1d16_UPD:
2201     case ARM::VST1d32_UPD:
2202     case ARM::VST1d64_UPD:
2203     case ARM::VST1q8_UPD:
2204     case ARM::VST1q16_UPD:
2205     case ARM::VST1q32_UPD:
2206     case ARM::VST1q64_UPD:
2207     case ARM::VST1d8T_UPD:
2208     case ARM::VST1d16T_UPD:
2209     case ARM::VST1d32T_UPD:
2210     case ARM::VST1d64T_UPD:
2211     case ARM::VST1d8Q_UPD:
2212     case ARM::VST1d16Q_UPD:
2213     case ARM::VST1d32Q_UPD:
2214     case ARM::VST1d64Q_UPD:
2215     case ARM::VST2d8_UPD:
2216     case ARM::VST2d16_UPD:
2217     case ARM::VST2d32_UPD:
2218     case ARM::VST2q8_UPD:
2219     case ARM::VST2q16_UPD:
2220     case ARM::VST2q32_UPD:
2221     case ARM::VST2b8_UPD:
2222     case ARM::VST2b16_UPD:
2223     case ARM::VST2b32_UPD:
2224     case ARM::VST3d8_UPD:
2225     case ARM::VST3d16_UPD:
2226     case ARM::VST3d32_UPD:
2227     case ARM::VST3q8_UPD:
2228     case ARM::VST3q16_UPD:
2229     case ARM::VST3q32_UPD:
2230     case ARM::VST4d8_UPD:
2231     case ARM::VST4d16_UPD:
2232     case ARM::VST4d32_UPD:
2233     case ARM::VST4q8_UPD:
2234     case ARM::VST4q16_UPD:
2235     case ARM::VST4q32_UPD:
2236       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2237         return MCDisassembler::Fail;
2238       break;
2239     default:
2240       break;
2241   }
2242 
2243   // AddrMode6 Base (register+alignment)
2244   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2245     return MCDisassembler::Fail;
2246 
2247   // AddrMode6 Offset (register)
2248   if (Rm == 0xD)
2249     Inst.addOperand(MCOperand::CreateReg(0));
2250   else if (Rm != 0xF) {
2251     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2252     return MCDisassembler::Fail;
2253   }
2254 
2255   // First input register
2256   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2257     return MCDisassembler::Fail;
2258 
2259   // Second input register
2260   switch (Inst.getOpcode()) {
2261     case ARM::VST1q8:
2262     case ARM::VST1q16:
2263     case ARM::VST1q32:
2264     case ARM::VST1q64:
2265     case ARM::VST1q8_UPD:
2266     case ARM::VST1q16_UPD:
2267     case ARM::VST1q32_UPD:
2268     case ARM::VST1q64_UPD:
2269     case ARM::VST1d8T:
2270     case ARM::VST1d16T:
2271     case ARM::VST1d32T:
2272     case ARM::VST1d64T:
2273     case ARM::VST1d8T_UPD:
2274     case ARM::VST1d16T_UPD:
2275     case ARM::VST1d32T_UPD:
2276     case ARM::VST1d64T_UPD:
2277     case ARM::VST1d8Q:
2278     case ARM::VST1d16Q:
2279     case ARM::VST1d32Q:
2280     case ARM::VST1d64Q:
2281     case ARM::VST1d8Q_UPD:
2282     case ARM::VST1d16Q_UPD:
2283     case ARM::VST1d32Q_UPD:
2284     case ARM::VST1d64Q_UPD:
2285     case ARM::VST2d8:
2286     case ARM::VST2d16:
2287     case ARM::VST2d32:
2288     case ARM::VST2d8_UPD:
2289     case ARM::VST2d16_UPD:
2290     case ARM::VST2d32_UPD:
2291     case ARM::VST2q8:
2292     case ARM::VST2q16:
2293     case ARM::VST2q32:
2294     case ARM::VST2q8_UPD:
2295     case ARM::VST2q16_UPD:
2296     case ARM::VST2q32_UPD:
2297     case ARM::VST3d8:
2298     case ARM::VST3d16:
2299     case ARM::VST3d32:
2300     case ARM::VST3d8_UPD:
2301     case ARM::VST3d16_UPD:
2302     case ARM::VST3d32_UPD:
2303     case ARM::VST4d8:
2304     case ARM::VST4d16:
2305     case ARM::VST4d32:
2306     case ARM::VST4d8_UPD:
2307     case ARM::VST4d16_UPD:
2308     case ARM::VST4d32_UPD:
2309       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2310         return MCDisassembler::Fail;
2311       break;
2312     case ARM::VST2b8:
2313     case ARM::VST2b16:
2314     case ARM::VST2b32:
2315     case ARM::VST2b8_UPD:
2316     case ARM::VST2b16_UPD:
2317     case ARM::VST2b32_UPD:
2318     case ARM::VST3q8:
2319     case ARM::VST3q16:
2320     case ARM::VST3q32:
2321     case ARM::VST3q8_UPD:
2322     case ARM::VST3q16_UPD:
2323     case ARM::VST3q32_UPD:
2324     case ARM::VST4q8:
2325     case ARM::VST4q16:
2326     case ARM::VST4q32:
2327     case ARM::VST4q8_UPD:
2328     case ARM::VST4q16_UPD:
2329     case ARM::VST4q32_UPD:
2330       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2331         return MCDisassembler::Fail;
2332       break;
2333     default:
2334       break;
2335   }
2336 
2337   // Third input register
2338   switch (Inst.getOpcode()) {
2339     case ARM::VST1d8T:
2340     case ARM::VST1d16T:
2341     case ARM::VST1d32T:
2342     case ARM::VST1d64T:
2343     case ARM::VST1d8T_UPD:
2344     case ARM::VST1d16T_UPD:
2345     case ARM::VST1d32T_UPD:
2346     case ARM::VST1d64T_UPD:
2347     case ARM::VST1d8Q:
2348     case ARM::VST1d16Q:
2349     case ARM::VST1d32Q:
2350     case ARM::VST1d64Q:
2351     case ARM::VST1d8Q_UPD:
2352     case ARM::VST1d16Q_UPD:
2353     case ARM::VST1d32Q_UPD:
2354     case ARM::VST1d64Q_UPD:
2355     case ARM::VST2q8:
2356     case ARM::VST2q16:
2357     case ARM::VST2q32:
2358     case ARM::VST2q8_UPD:
2359     case ARM::VST2q16_UPD:
2360     case ARM::VST2q32_UPD:
2361     case ARM::VST3d8:
2362     case ARM::VST3d16:
2363     case ARM::VST3d32:
2364     case ARM::VST3d8_UPD:
2365     case ARM::VST3d16_UPD:
2366     case ARM::VST3d32_UPD:
2367     case ARM::VST4d8:
2368     case ARM::VST4d16:
2369     case ARM::VST4d32:
2370     case ARM::VST4d8_UPD:
2371     case ARM::VST4d16_UPD:
2372     case ARM::VST4d32_UPD:
2373       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2374         return MCDisassembler::Fail;
2375       break;
2376     case ARM::VST3q8:
2377     case ARM::VST3q16:
2378     case ARM::VST3q32:
2379     case ARM::VST3q8_UPD:
2380     case ARM::VST3q16_UPD:
2381     case ARM::VST3q32_UPD:
2382     case ARM::VST4q8:
2383     case ARM::VST4q16:
2384     case ARM::VST4q32:
2385     case ARM::VST4q8_UPD:
2386     case ARM::VST4q16_UPD:
2387     case ARM::VST4q32_UPD:
2388       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2389         return MCDisassembler::Fail;
2390       break;
2391     default:
2392       break;
2393   }
2394 
2395   // Fourth input register
2396   switch (Inst.getOpcode()) {
2397     case ARM::VST1d8Q:
2398     case ARM::VST1d16Q:
2399     case ARM::VST1d32Q:
2400     case ARM::VST1d64Q:
2401     case ARM::VST1d8Q_UPD:
2402     case ARM::VST1d16Q_UPD:
2403     case ARM::VST1d32Q_UPD:
2404     case ARM::VST1d64Q_UPD:
2405     case ARM::VST2q8:
2406     case ARM::VST2q16:
2407     case ARM::VST2q32:
2408     case ARM::VST2q8_UPD:
2409     case ARM::VST2q16_UPD:
2410     case ARM::VST2q32_UPD:
2411     case ARM::VST4d8:
2412     case ARM::VST4d16:
2413     case ARM::VST4d32:
2414     case ARM::VST4d8_UPD:
2415     case ARM::VST4d16_UPD:
2416     case ARM::VST4d32_UPD:
2417       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2418         return MCDisassembler::Fail;
2419       break;
2420     case ARM::VST4q8:
2421     case ARM::VST4q16:
2422     case ARM::VST4q32:
2423     case ARM::VST4q8_UPD:
2424     case ARM::VST4q16_UPD:
2425     case ARM::VST4q32_UPD:
2426       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2427         return MCDisassembler::Fail;
2428       break;
2429     default:
2430       break;
2431   }
2432 
2433   return S;
2434 }
2435 
2436 static DecodeStatus DecodeVLD1DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2437                                     uint64_t Address, const void *Decoder) {
2438   DecodeStatus S = MCDisassembler::Success;
2439 
2440   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2441   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2442   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2443   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2444   unsigned align = fieldFromInstruction32(Insn, 4, 1);
2445   unsigned size = fieldFromInstruction32(Insn, 6, 2);
2446   unsigned regs = fieldFromInstruction32(Insn, 5, 1) + 1;
2447 
2448   align *= (1 << size);
2449 
2450   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2451     return MCDisassembler::Fail;
2452   if (regs == 2) {
2453     if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2454       return MCDisassembler::Fail;
2455   }
2456   if (Rm != 0xF) {
2457     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2458       return MCDisassembler::Fail;
2459   }
2460 
2461   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2462     return MCDisassembler::Fail;
2463   Inst.addOperand(MCOperand::CreateImm(align));
2464 
2465   if (Rm == 0xD)
2466     Inst.addOperand(MCOperand::CreateReg(0));
2467   else if (Rm != 0xF) {
2468     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2469       return MCDisassembler::Fail;
2470   }
2471 
2472   return S;
2473 }
2474 
2475 static DecodeStatus DecodeVLD2DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2476                                     uint64_t Address, const void *Decoder) {
2477   DecodeStatus S = MCDisassembler::Success;
2478 
2479   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2480   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2481   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2482   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2483   unsigned align = fieldFromInstruction32(Insn, 4, 1);
2484   unsigned size = 1 << fieldFromInstruction32(Insn, 6, 2);
2485   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2486   align *= 2*size;
2487 
2488   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2489     return MCDisassembler::Fail;
2490   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
2491     return MCDisassembler::Fail;
2492   if (Rm != 0xF) {
2493     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2494       return MCDisassembler::Fail;
2495   }
2496 
2497   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2498     return MCDisassembler::Fail;
2499   Inst.addOperand(MCOperand::CreateImm(align));
2500 
2501   if (Rm == 0xD)
2502     Inst.addOperand(MCOperand::CreateReg(0));
2503   else if (Rm != 0xF) {
2504     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2505       return MCDisassembler::Fail;
2506   }
2507 
2508   return S;
2509 }
2510 
2511 static DecodeStatus DecodeVLD3DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2512                                     uint64_t Address, const void *Decoder) {
2513   DecodeStatus S = MCDisassembler::Success;
2514 
2515   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2516   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2517   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2518   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2519   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2520 
2521   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2522     return MCDisassembler::Fail;
2523   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
2524     return MCDisassembler::Fail;
2525   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
2526     return MCDisassembler::Fail;
2527   if (Rm != 0xF) {
2528     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2529       return MCDisassembler::Fail;
2530   }
2531 
2532   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2533     return MCDisassembler::Fail;
2534   Inst.addOperand(MCOperand::CreateImm(0));
2535 
2536   if (Rm == 0xD)
2537     Inst.addOperand(MCOperand::CreateReg(0));
2538   else if (Rm != 0xF) {
2539     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2540       return MCDisassembler::Fail;
2541   }
2542 
2543   return S;
2544 }
2545 
2546 static DecodeStatus DecodeVLD4DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2547                                     uint64_t Address, const void *Decoder) {
2548   DecodeStatus S = MCDisassembler::Success;
2549 
2550   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2551   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2552   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2553   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2554   unsigned size = fieldFromInstruction32(Insn, 6, 2);
2555   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2556   unsigned align = fieldFromInstruction32(Insn, 4, 1);
2557 
2558   if (size == 0x3) {
2559     size = 4;
2560     align = 16;
2561   } else {
2562     if (size == 2) {
2563       size = 1 << size;
2564       align *= 8;
2565     } else {
2566       size = 1 << size;
2567       align *= 4*size;
2568     }
2569   }
2570 
2571   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2572     return MCDisassembler::Fail;
2573   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
2574     return MCDisassembler::Fail;
2575   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
2576     return MCDisassembler::Fail;
2577   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
2578     return MCDisassembler::Fail;
2579   if (Rm != 0xF) {
2580     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2581       return MCDisassembler::Fail;
2582   }
2583 
2584   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2585     return MCDisassembler::Fail;
2586   Inst.addOperand(MCOperand::CreateImm(align));
2587 
2588   if (Rm == 0xD)
2589     Inst.addOperand(MCOperand::CreateReg(0));
2590   else if (Rm != 0xF) {
2591     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2592       return MCDisassembler::Fail;
2593   }
2594 
2595   return S;
2596 }
2597 
2598 static DecodeStatus
2599 DecodeNEONModImmInstruction(llvm::MCInst &Inst, unsigned Insn,
2600                             uint64_t Address, const void *Decoder) {
2601   DecodeStatus S = MCDisassembler::Success;
2602 
2603   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2604   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2605   unsigned imm = fieldFromInstruction32(Insn, 0, 4);
2606   imm |= fieldFromInstruction32(Insn, 16, 3) << 4;
2607   imm |= fieldFromInstruction32(Insn, 24, 1) << 7;
2608   imm |= fieldFromInstruction32(Insn, 8, 4) << 8;
2609   imm |= fieldFromInstruction32(Insn, 5, 1) << 12;
2610   unsigned Q = fieldFromInstruction32(Insn, 6, 1);
2611 
2612   if (Q) {
2613     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
2614     return MCDisassembler::Fail;
2615   } else {
2616     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2617     return MCDisassembler::Fail;
2618   }
2619 
2620   Inst.addOperand(MCOperand::CreateImm(imm));
2621 
2622   switch (Inst.getOpcode()) {
2623     case ARM::VORRiv4i16:
2624     case ARM::VORRiv2i32:
2625     case ARM::VBICiv4i16:
2626     case ARM::VBICiv2i32:
2627       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2628         return MCDisassembler::Fail;
2629       break;
2630     case ARM::VORRiv8i16:
2631     case ARM::VORRiv4i32:
2632     case ARM::VBICiv8i16:
2633     case ARM::VBICiv4i32:
2634       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
2635         return MCDisassembler::Fail;
2636       break;
2637     default:
2638       break;
2639   }
2640 
2641   return S;
2642 }
2643 
2644 static DecodeStatus DecodeVSHLMaxInstruction(llvm::MCInst &Inst, unsigned Insn,
2645                                         uint64_t Address, const void *Decoder) {
2646   DecodeStatus S = MCDisassembler::Success;
2647 
2648   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2649   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2650   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2651   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2652   unsigned size = fieldFromInstruction32(Insn, 18, 2);
2653 
2654   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
2655     return MCDisassembler::Fail;
2656   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
2657     return MCDisassembler::Fail;
2658   Inst.addOperand(MCOperand::CreateImm(8 << size));
2659 
2660   return S;
2661 }
2662 
2663 static DecodeStatus DecodeShiftRight8Imm(llvm::MCInst &Inst, unsigned Val,
2664                                uint64_t Address, const void *Decoder) {
2665   Inst.addOperand(MCOperand::CreateImm(8 - Val));
2666   return MCDisassembler::Success;
2667 }
2668 
2669 static DecodeStatus DecodeShiftRight16Imm(llvm::MCInst &Inst, unsigned Val,
2670                                uint64_t Address, const void *Decoder) {
2671   Inst.addOperand(MCOperand::CreateImm(16 - Val));
2672   return MCDisassembler::Success;
2673 }
2674 
2675 static DecodeStatus DecodeShiftRight32Imm(llvm::MCInst &Inst, unsigned Val,
2676                                uint64_t Address, const void *Decoder) {
2677   Inst.addOperand(MCOperand::CreateImm(32 - Val));
2678   return MCDisassembler::Success;
2679 }
2680 
2681 static DecodeStatus DecodeShiftRight64Imm(llvm::MCInst &Inst, unsigned Val,
2682                                uint64_t Address, const void *Decoder) {
2683   Inst.addOperand(MCOperand::CreateImm(64 - Val));
2684   return MCDisassembler::Success;
2685 }
2686 
2687 static DecodeStatus DecodeTBLInstruction(llvm::MCInst &Inst, unsigned Insn,
2688                                uint64_t Address, const void *Decoder) {
2689   DecodeStatus S = MCDisassembler::Success;
2690 
2691   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2692   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2693   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2694   Rn |= fieldFromInstruction32(Insn, 7, 1) << 4;
2695   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2696   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2697   unsigned op = fieldFromInstruction32(Insn, 6, 1);
2698   unsigned length = fieldFromInstruction32(Insn, 8, 2) + 1;
2699 
2700   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2701     return MCDisassembler::Fail;
2702   if (op) {
2703     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2704     return MCDisassembler::Fail; // Writeback
2705   }
2706 
2707   for (unsigned i = 0; i < length; ++i) {
2708     if (!Check(S, DecodeDPRRegisterClass(Inst, (Rn+i)%32, Address, Decoder)))
2709     return MCDisassembler::Fail;
2710   }
2711 
2712   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
2713     return MCDisassembler::Fail;
2714 
2715   return S;
2716 }
2717 
2718 static DecodeStatus DecodeThumbAddSpecialReg(llvm::MCInst &Inst, uint16_t Insn,
2719                                      uint64_t Address, const void *Decoder) {
2720   DecodeStatus S = MCDisassembler::Success;
2721 
2722   unsigned dst = fieldFromInstruction16(Insn, 8, 3);
2723   unsigned imm = fieldFromInstruction16(Insn, 0, 8);
2724 
2725   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
2726     return MCDisassembler::Fail;
2727 
2728   switch(Inst.getOpcode()) {
2729     default:
2730       return MCDisassembler::Fail;
2731     case ARM::tADR:
2732       break; // tADR does not explicitly represent the PC as an operand.
2733     case ARM::tADDrSPi:
2734       Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2735       break;
2736   }
2737 
2738   Inst.addOperand(MCOperand::CreateImm(imm));
2739   return S;
2740 }
2741 
2742 static DecodeStatus DecodeThumbBROperand(llvm::MCInst &Inst, unsigned Val,
2743                                  uint64_t Address, const void *Decoder) {
2744   Inst.addOperand(MCOperand::CreateImm(SignExtend32<12>(Val << 1)));
2745   return MCDisassembler::Success;
2746 }
2747 
2748 static DecodeStatus DecodeT2BROperand(llvm::MCInst &Inst, unsigned Val,
2749                                  uint64_t Address, const void *Decoder) {
2750   Inst.addOperand(MCOperand::CreateImm(SignExtend32<21>(Val)));
2751   return MCDisassembler::Success;
2752 }
2753 
2754 static DecodeStatus DecodeThumbCmpBROperand(llvm::MCInst &Inst, unsigned Val,
2755                                  uint64_t Address, const void *Decoder) {
2756   Inst.addOperand(MCOperand::CreateImm(SignExtend32<7>(Val << 1)));
2757   return MCDisassembler::Success;
2758 }
2759 
2760 static DecodeStatus DecodeThumbAddrModeRR(llvm::MCInst &Inst, unsigned Val,
2761                                  uint64_t Address, const void *Decoder) {
2762   DecodeStatus S = MCDisassembler::Success;
2763 
2764   unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2765   unsigned Rm = fieldFromInstruction32(Val, 3, 3);
2766 
2767   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
2768     return MCDisassembler::Fail;
2769   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
2770     return MCDisassembler::Fail;
2771 
2772   return S;
2773 }
2774 
2775 static DecodeStatus DecodeThumbAddrModeIS(llvm::MCInst &Inst, unsigned Val,
2776                                   uint64_t Address, const void *Decoder) {
2777   DecodeStatus S = MCDisassembler::Success;
2778 
2779   unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2780   unsigned imm = fieldFromInstruction32(Val, 3, 5);
2781 
2782   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
2783     return MCDisassembler::Fail;
2784   Inst.addOperand(MCOperand::CreateImm(imm));
2785 
2786   return S;
2787 }
2788 
2789 static DecodeStatus DecodeThumbAddrModePC(llvm::MCInst &Inst, unsigned Val,
2790                                   uint64_t Address, const void *Decoder) {
2791   unsigned imm = Val << 2;
2792 
2793   Inst.addOperand(MCOperand::CreateImm(imm));
2794   tryAddingPcLoadReferenceComment(Address, (Address & ~2u) + imm + 4, Decoder);
2795 
2796   return MCDisassembler::Success;
2797 }
2798 
2799 static DecodeStatus DecodeThumbAddrModeSP(llvm::MCInst &Inst, unsigned Val,
2800                                   uint64_t Address, const void *Decoder) {
2801   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2802   Inst.addOperand(MCOperand::CreateImm(Val));
2803 
2804   return MCDisassembler::Success;
2805 }
2806 
2807 static DecodeStatus DecodeT2AddrModeSOReg(llvm::MCInst &Inst, unsigned Val,
2808                                   uint64_t Address, const void *Decoder) {
2809   DecodeStatus S = MCDisassembler::Success;
2810 
2811   unsigned Rn = fieldFromInstruction32(Val, 6, 4);
2812   unsigned Rm = fieldFromInstruction32(Val, 2, 4);
2813   unsigned imm = fieldFromInstruction32(Val, 0, 2);
2814 
2815   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2816     return MCDisassembler::Fail;
2817   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
2818     return MCDisassembler::Fail;
2819   Inst.addOperand(MCOperand::CreateImm(imm));
2820 
2821   return S;
2822 }
2823 
2824 static DecodeStatus DecodeT2LoadShift(llvm::MCInst &Inst, unsigned Insn,
2825                               uint64_t Address, const void *Decoder) {
2826   DecodeStatus S = MCDisassembler::Success;
2827 
2828   switch (Inst.getOpcode()) {
2829     case ARM::t2PLDs:
2830     case ARM::t2PLDWs:
2831     case ARM::t2PLIs:
2832       break;
2833     default: {
2834       unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2835       if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
2836     return MCDisassembler::Fail;
2837     }
2838   }
2839 
2840   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2841   if (Rn == 0xF) {
2842     switch (Inst.getOpcode()) {
2843       case ARM::t2LDRBs:
2844         Inst.setOpcode(ARM::t2LDRBpci);
2845         break;
2846       case ARM::t2LDRHs:
2847         Inst.setOpcode(ARM::t2LDRHpci);
2848         break;
2849       case ARM::t2LDRSHs:
2850         Inst.setOpcode(ARM::t2LDRSHpci);
2851         break;
2852       case ARM::t2LDRSBs:
2853         Inst.setOpcode(ARM::t2LDRSBpci);
2854         break;
2855       case ARM::t2PLDs:
2856         Inst.setOpcode(ARM::t2PLDi12);
2857         Inst.addOperand(MCOperand::CreateReg(ARM::PC));
2858         break;
2859       default:
2860         return MCDisassembler::Fail;
2861     }
2862 
2863     int imm = fieldFromInstruction32(Insn, 0, 12);
2864     if (!fieldFromInstruction32(Insn, 23, 1)) imm *= -1;
2865     Inst.addOperand(MCOperand::CreateImm(imm));
2866 
2867     return S;
2868   }
2869 
2870   unsigned addrmode = fieldFromInstruction32(Insn, 4, 2);
2871   addrmode |= fieldFromInstruction32(Insn, 0, 4) << 2;
2872   addrmode |= fieldFromInstruction32(Insn, 16, 4) << 6;
2873   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
2874     return MCDisassembler::Fail;
2875 
2876   return S;
2877 }
2878 
2879 static DecodeStatus DecodeT2Imm8S4(llvm::MCInst &Inst, unsigned Val,
2880                            uint64_t Address, const void *Decoder) {
2881   int imm = Val & 0xFF;
2882   if (!(Val & 0x100)) imm *= -1;
2883   Inst.addOperand(MCOperand::CreateImm(imm << 2));
2884 
2885   return MCDisassembler::Success;
2886 }
2887 
2888 static DecodeStatus DecodeT2AddrModeImm8s4(llvm::MCInst &Inst, unsigned Val,
2889                                    uint64_t Address, const void *Decoder) {
2890   DecodeStatus S = MCDisassembler::Success;
2891 
2892   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2893   unsigned imm = fieldFromInstruction32(Val, 0, 9);
2894 
2895   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2896     return MCDisassembler::Fail;
2897   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
2898     return MCDisassembler::Fail;
2899 
2900   return S;
2901 }
2902 
2903 static DecodeStatus DecodeT2AddrModeImm0_1020s4(llvm::MCInst &Inst,unsigned Val,
2904                                    uint64_t Address, const void *Decoder) {
2905   DecodeStatus S = MCDisassembler::Success;
2906 
2907   unsigned Rn = fieldFromInstruction32(Val, 8, 4);
2908   unsigned imm = fieldFromInstruction32(Val, 0, 8);
2909 
2910   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2911     return MCDisassembler::Fail;
2912 
2913   Inst.addOperand(MCOperand::CreateImm(imm));
2914 
2915   return S;
2916 }
2917 
2918 static DecodeStatus DecodeT2Imm8(llvm::MCInst &Inst, unsigned Val,
2919                          uint64_t Address, const void *Decoder) {
2920   int imm = Val & 0xFF;
2921   if (Val == 0)
2922     imm = INT32_MIN;
2923   else if (!(Val & 0x100))
2924     imm *= -1;
2925   Inst.addOperand(MCOperand::CreateImm(imm));
2926 
2927   return MCDisassembler::Success;
2928 }
2929 
2930 
2931 static DecodeStatus DecodeT2AddrModeImm8(llvm::MCInst &Inst, unsigned Val,
2932                                  uint64_t Address, const void *Decoder) {
2933   DecodeStatus S = MCDisassembler::Success;
2934 
2935   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2936   unsigned imm = fieldFromInstruction32(Val, 0, 9);
2937 
2938   // Some instructions always use an additive offset.
2939   switch (Inst.getOpcode()) {
2940     case ARM::t2LDRT:
2941     case ARM::t2LDRBT:
2942     case ARM::t2LDRHT:
2943     case ARM::t2LDRSBT:
2944     case ARM::t2LDRSHT:
2945     case ARM::t2STRT:
2946     case ARM::t2STRBT:
2947     case ARM::t2STRHT:
2948       imm |= 0x100;
2949       break;
2950     default:
2951       break;
2952   }
2953 
2954   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2955     return MCDisassembler::Fail;
2956   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
2957     return MCDisassembler::Fail;
2958 
2959   return S;
2960 }
2961 
2962 static DecodeStatus DecodeT2LdStPre(llvm::MCInst &Inst, unsigned Insn,
2963                                     uint64_t Address, const void *Decoder) {
2964   DecodeStatus S = MCDisassembler::Success;
2965 
2966   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2967   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2968   unsigned addr = fieldFromInstruction32(Insn, 0, 8);
2969   addr |= fieldFromInstruction32(Insn, 9, 1) << 8;
2970   addr |= Rn << 9;
2971   unsigned load = fieldFromInstruction32(Insn, 20, 1);
2972 
2973   if (!load) {
2974     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2975       return MCDisassembler::Fail;
2976   }
2977 
2978   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
2979     return MCDisassembler::Fail;
2980 
2981   if (load) {
2982     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2983       return MCDisassembler::Fail;
2984   }
2985 
2986   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
2987     return MCDisassembler::Fail;
2988 
2989   return S;
2990 }
2991 
2992 static DecodeStatus DecodeT2AddrModeImm12(llvm::MCInst &Inst, unsigned Val,
2993                                   uint64_t Address, const void *Decoder) {
2994   DecodeStatus S = MCDisassembler::Success;
2995 
2996   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
2997   unsigned imm = fieldFromInstruction32(Val, 0, 12);
2998 
2999   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3000     return MCDisassembler::Fail;
3001   Inst.addOperand(MCOperand::CreateImm(imm));
3002 
3003   return S;
3004 }
3005 
3006 
3007 static DecodeStatus DecodeThumbAddSPImm(llvm::MCInst &Inst, uint16_t Insn,
3008                                 uint64_t Address, const void *Decoder) {
3009   unsigned imm = fieldFromInstruction16(Insn, 0, 7);
3010 
3011   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
3012   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
3013   Inst.addOperand(MCOperand::CreateImm(imm));
3014 
3015   return MCDisassembler::Success;
3016 }
3017 
3018 static DecodeStatus DecodeThumbAddSPReg(llvm::MCInst &Inst, uint16_t Insn,
3019                                 uint64_t Address, const void *Decoder) {
3020   DecodeStatus S = MCDisassembler::Success;
3021 
3022   if (Inst.getOpcode() == ARM::tADDrSP) {
3023     unsigned Rdm = fieldFromInstruction16(Insn, 0, 3);
3024     Rdm |= fieldFromInstruction16(Insn, 7, 1) << 3;
3025 
3026     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
3027     return MCDisassembler::Fail;
3028     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
3029     return MCDisassembler::Fail;
3030     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
3031   } else if (Inst.getOpcode() == ARM::tADDspr) {
3032     unsigned Rm = fieldFromInstruction16(Insn, 3, 4);
3033 
3034     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
3035     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
3036     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3037     return MCDisassembler::Fail;
3038   }
3039 
3040   return S;
3041 }
3042 
3043 static DecodeStatus DecodeThumbCPS(llvm::MCInst &Inst, uint16_t Insn,
3044                            uint64_t Address, const void *Decoder) {
3045   unsigned imod = fieldFromInstruction16(Insn, 4, 1) | 0x2;
3046   unsigned flags = fieldFromInstruction16(Insn, 0, 3);
3047 
3048   Inst.addOperand(MCOperand::CreateImm(imod));
3049   Inst.addOperand(MCOperand::CreateImm(flags));
3050 
3051   return MCDisassembler::Success;
3052 }
3053 
3054 static DecodeStatus DecodePostIdxReg(llvm::MCInst &Inst, unsigned Insn,
3055                              uint64_t Address, const void *Decoder) {
3056   DecodeStatus S = MCDisassembler::Success;
3057   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3058   unsigned add = fieldFromInstruction32(Insn, 4, 1);
3059 
3060   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3061     return MCDisassembler::Fail;
3062   Inst.addOperand(MCOperand::CreateImm(add));
3063 
3064   return S;
3065 }
3066 
3067 static DecodeStatus DecodeThumbBLXOffset(llvm::MCInst &Inst, unsigned Val,
3068                                  uint64_t Address, const void *Decoder) {
3069   if (!tryAddingSymbolicOperand(Address,
3070                                 (Address & ~2u) + SignExtend32<22>(Val << 1) + 4,
3071                                 true, 4, Inst, Decoder))
3072     Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
3073   return MCDisassembler::Success;
3074 }
3075 
3076 static DecodeStatus DecodeCoprocessor(llvm::MCInst &Inst, unsigned Val,
3077                               uint64_t Address, const void *Decoder) {
3078   if (Val == 0xA || Val == 0xB)
3079     return MCDisassembler::Fail;
3080 
3081   Inst.addOperand(MCOperand::CreateImm(Val));
3082   return MCDisassembler::Success;
3083 }
3084 
3085 static DecodeStatus
3086 DecodeThumbTableBranch(llvm::MCInst &Inst, unsigned Insn,
3087                        uint64_t Address, const void *Decoder) {
3088   DecodeStatus S = MCDisassembler::Success;
3089 
3090   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3091   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3092 
3093   if (Rn == ARM::SP) S = MCDisassembler::SoftFail;
3094   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3095     return MCDisassembler::Fail;
3096   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
3097     return MCDisassembler::Fail;
3098   return S;
3099 }
3100 
3101 static DecodeStatus
3102 DecodeThumb2BCCInstruction(llvm::MCInst &Inst, unsigned Insn,
3103                            uint64_t Address, const void *Decoder) {
3104   DecodeStatus S = MCDisassembler::Success;
3105 
3106   unsigned pred = fieldFromInstruction32(Insn, 22, 4);
3107   if (pred == 0xE || pred == 0xF) {
3108     unsigned opc = fieldFromInstruction32(Insn, 4, 28);
3109     switch (opc) {
3110       default:
3111         return MCDisassembler::Fail;
3112       case 0xf3bf8f4:
3113         Inst.setOpcode(ARM::t2DSB);
3114         break;
3115       case 0xf3bf8f5:
3116         Inst.setOpcode(ARM::t2DMB);
3117         break;
3118       case 0xf3bf8f6:
3119         Inst.setOpcode(ARM::t2ISB);
3120         break;
3121     }
3122 
3123     unsigned imm = fieldFromInstruction32(Insn, 0, 4);
3124     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
3125   }
3126 
3127   unsigned brtarget = fieldFromInstruction32(Insn, 0, 11) << 1;
3128   brtarget |= fieldFromInstruction32(Insn, 11, 1) << 19;
3129   brtarget |= fieldFromInstruction32(Insn, 13, 1) << 18;
3130   brtarget |= fieldFromInstruction32(Insn, 16, 6) << 12;
3131   brtarget |= fieldFromInstruction32(Insn, 26, 1) << 20;
3132 
3133   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
3134     return MCDisassembler::Fail;
3135   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3136     return MCDisassembler::Fail;
3137 
3138   return S;
3139 }
3140 
3141 // Decode a shifted immediate operand.  These basically consist
3142 // of an 8-bit value, and a 4-bit directive that specifies either
3143 // a splat operation or a rotation.
3144 static DecodeStatus DecodeT2SOImm(llvm::MCInst &Inst, unsigned Val,
3145                           uint64_t Address, const void *Decoder) {
3146   unsigned ctrl = fieldFromInstruction32(Val, 10, 2);
3147   if (ctrl == 0) {
3148     unsigned byte = fieldFromInstruction32(Val, 8, 2);
3149     unsigned imm = fieldFromInstruction32(Val, 0, 8);
3150     switch (byte) {
3151       case 0:
3152         Inst.addOperand(MCOperand::CreateImm(imm));
3153         break;
3154       case 1:
3155         Inst.addOperand(MCOperand::CreateImm((imm << 16) | imm));
3156         break;
3157       case 2:
3158         Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 8)));
3159         break;
3160       case 3:
3161         Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 16) |
3162                                              (imm << 8)  |  imm));
3163         break;
3164     }
3165   } else {
3166     unsigned unrot = fieldFromInstruction32(Val, 0, 7) | 0x80;
3167     unsigned rot = fieldFromInstruction32(Val, 7, 5);
3168     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
3169     Inst.addOperand(MCOperand::CreateImm(imm));
3170   }
3171 
3172   return MCDisassembler::Success;
3173 }
3174 
3175 static DecodeStatus
3176 DecodeThumbBCCTargetOperand(llvm::MCInst &Inst, unsigned Val,
3177                             uint64_t Address, const void *Decoder){
3178   Inst.addOperand(MCOperand::CreateImm(Val << 1));
3179   return MCDisassembler::Success;
3180 }
3181 
3182 static DecodeStatus DecodeThumbBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
3183                                        uint64_t Address, const void *Decoder){
3184   Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
3185   return MCDisassembler::Success;
3186 }
3187 
3188 static DecodeStatus DecodeMemBarrierOption(llvm::MCInst &Inst, unsigned Val,
3189                                    uint64_t Address, const void *Decoder) {
3190   switch (Val) {
3191   default:
3192     return MCDisassembler::Fail;
3193   case 0xF: // SY
3194   case 0xE: // ST
3195   case 0xB: // ISH
3196   case 0xA: // ISHST
3197   case 0x7: // NSH
3198   case 0x6: // NSHST
3199   case 0x3: // OSH
3200   case 0x2: // OSHST
3201     break;
3202   }
3203 
3204   Inst.addOperand(MCOperand::CreateImm(Val));
3205   return MCDisassembler::Success;
3206 }
3207 
3208 static DecodeStatus DecodeMSRMask(llvm::MCInst &Inst, unsigned Val,
3209                           uint64_t Address, const void *Decoder) {
3210   if (!Val) return MCDisassembler::Fail;
3211   Inst.addOperand(MCOperand::CreateImm(Val));
3212   return MCDisassembler::Success;
3213 }
3214 
3215 static DecodeStatus DecodeDoubleRegLoad(llvm::MCInst &Inst, unsigned Insn,
3216                                         uint64_t Address, const void *Decoder) {
3217   DecodeStatus S = MCDisassembler::Success;
3218 
3219   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3220   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3221   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3222 
3223   if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return MCDisassembler::Fail;
3224 
3225   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3226     return MCDisassembler::Fail;
3227   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
3228     return MCDisassembler::Fail;
3229   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3230     return MCDisassembler::Fail;
3231   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3232     return MCDisassembler::Fail;
3233 
3234   return S;
3235 }
3236 
3237 
3238 static DecodeStatus DecodeDoubleRegStore(llvm::MCInst &Inst, unsigned Insn,
3239                                          uint64_t Address, const void *Decoder){
3240   DecodeStatus S = MCDisassembler::Success;
3241 
3242   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3243   unsigned Rt = fieldFromInstruction32(Insn, 0, 4);
3244   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3245   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3246 
3247   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
3248     return MCDisassembler::Fail;
3249 
3250   if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return MCDisassembler::Fail;
3251   if (Rd == Rn || Rd == Rt || Rd == Rt+1) return MCDisassembler::Fail;
3252 
3253   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3254     return MCDisassembler::Fail;
3255   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
3256     return MCDisassembler::Fail;
3257   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3258     return MCDisassembler::Fail;
3259   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3260     return MCDisassembler::Fail;
3261 
3262   return S;
3263 }
3264 
3265 static DecodeStatus DecodeLDRPreImm(llvm::MCInst &Inst, unsigned Insn,
3266                             uint64_t Address, const void *Decoder) {
3267   DecodeStatus S = MCDisassembler::Success;
3268 
3269   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3270   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3271   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3272   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3273   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3274   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3275 
3276   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3277 
3278   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3279     return MCDisassembler::Fail;
3280   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3281     return MCDisassembler::Fail;
3282   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
3283     return MCDisassembler::Fail;
3284   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3285     return MCDisassembler::Fail;
3286 
3287   return S;
3288 }
3289 
3290 static DecodeStatus DecodeLDRPreReg(llvm::MCInst &Inst, unsigned Insn,
3291                             uint64_t Address, const void *Decoder) {
3292   DecodeStatus S = MCDisassembler::Success;
3293 
3294   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3295   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3296   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3297   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3298   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3299   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3300   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3301 
3302   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3303   if (Rm == 0xF) S = MCDisassembler::SoftFail;
3304 
3305   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3306     return MCDisassembler::Fail;
3307   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3308     return MCDisassembler::Fail;
3309   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
3310     return MCDisassembler::Fail;
3311   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3312     return MCDisassembler::Fail;
3313 
3314   return S;
3315 }
3316 
3317 
3318 static DecodeStatus DecodeSTRPreImm(llvm::MCInst &Inst, unsigned Insn,
3319                             uint64_t Address, const void *Decoder) {
3320   DecodeStatus S = MCDisassembler::Success;
3321 
3322   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3323   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3324   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3325   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3326   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3327   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3328 
3329   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3330 
3331   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3332     return MCDisassembler::Fail;
3333   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3334     return MCDisassembler::Fail;
3335   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
3336     return MCDisassembler::Fail;
3337   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3338     return MCDisassembler::Fail;
3339 
3340   return S;
3341 }
3342 
3343 static DecodeStatus DecodeSTRPreReg(llvm::MCInst &Inst, unsigned Insn,
3344                             uint64_t Address, const void *Decoder) {
3345   DecodeStatus S = MCDisassembler::Success;
3346 
3347   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3348   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3349   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3350   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3351   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3352   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3353 
3354   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3355 
3356   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3357     return MCDisassembler::Fail;
3358   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3359     return MCDisassembler::Fail;
3360   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
3361     return MCDisassembler::Fail;
3362   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3363     return MCDisassembler::Fail;
3364 
3365   return S;
3366 }
3367 
3368 static DecodeStatus DecodeVLD1LN(llvm::MCInst &Inst, unsigned Insn,
3369                          uint64_t Address, const void *Decoder) {
3370   DecodeStatus S = MCDisassembler::Success;
3371 
3372   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3373   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3374   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3375   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3376   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3377 
3378   unsigned align = 0;
3379   unsigned index = 0;
3380   switch (size) {
3381     default:
3382       return MCDisassembler::Fail;
3383     case 0:
3384       if (fieldFromInstruction32(Insn, 4, 1))
3385         return MCDisassembler::Fail; // UNDEFINED
3386       index = fieldFromInstruction32(Insn, 5, 3);
3387       break;
3388     case 1:
3389       if (fieldFromInstruction32(Insn, 5, 1))
3390         return MCDisassembler::Fail; // UNDEFINED
3391       index = fieldFromInstruction32(Insn, 6, 2);
3392       if (fieldFromInstruction32(Insn, 4, 1))
3393         align = 2;
3394       break;
3395     case 2:
3396       if (fieldFromInstruction32(Insn, 6, 1))
3397         return MCDisassembler::Fail; // UNDEFINED
3398       index = fieldFromInstruction32(Insn, 7, 1);
3399       if (fieldFromInstruction32(Insn, 4, 2) != 0)
3400         align = 4;
3401   }
3402 
3403   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3404     return MCDisassembler::Fail;
3405   if (Rm != 0xF) { // Writeback
3406     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3407       return MCDisassembler::Fail;
3408   }
3409   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3410     return MCDisassembler::Fail;
3411   Inst.addOperand(MCOperand::CreateImm(align));
3412   if (Rm != 0xF) {
3413     if (Rm != 0xD) {
3414       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3415         return MCDisassembler::Fail;
3416     } else
3417       Inst.addOperand(MCOperand::CreateReg(0));
3418   }
3419 
3420   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3421     return MCDisassembler::Fail;
3422   Inst.addOperand(MCOperand::CreateImm(index));
3423 
3424   return S;
3425 }
3426 
3427 static DecodeStatus DecodeVST1LN(llvm::MCInst &Inst, unsigned Insn,
3428                          uint64_t Address, const void *Decoder) {
3429   DecodeStatus S = MCDisassembler::Success;
3430 
3431   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3432   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3433   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3434   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3435   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3436 
3437   unsigned align = 0;
3438   unsigned index = 0;
3439   switch (size) {
3440     default:
3441       return MCDisassembler::Fail;
3442     case 0:
3443       if (fieldFromInstruction32(Insn, 4, 1))
3444         return MCDisassembler::Fail; // UNDEFINED
3445       index = fieldFromInstruction32(Insn, 5, 3);
3446       break;
3447     case 1:
3448       if (fieldFromInstruction32(Insn, 5, 1))
3449         return MCDisassembler::Fail; // UNDEFINED
3450       index = fieldFromInstruction32(Insn, 6, 2);
3451       if (fieldFromInstruction32(Insn, 4, 1))
3452         align = 2;
3453       break;
3454     case 2:
3455       if (fieldFromInstruction32(Insn, 6, 1))
3456         return MCDisassembler::Fail; // UNDEFINED
3457       index = fieldFromInstruction32(Insn, 7, 1);
3458       if (fieldFromInstruction32(Insn, 4, 2) != 0)
3459         align = 4;
3460   }
3461 
3462   if (Rm != 0xF) { // Writeback
3463     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3464     return MCDisassembler::Fail;
3465   }
3466   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3467     return MCDisassembler::Fail;
3468   Inst.addOperand(MCOperand::CreateImm(align));
3469   if (Rm != 0xF) {
3470     if (Rm != 0xD) {
3471       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3472     return MCDisassembler::Fail;
3473     } else
3474       Inst.addOperand(MCOperand::CreateReg(0));
3475   }
3476 
3477   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3478     return MCDisassembler::Fail;
3479   Inst.addOperand(MCOperand::CreateImm(index));
3480 
3481   return S;
3482 }
3483 
3484 
3485 static DecodeStatus DecodeVLD2LN(llvm::MCInst &Inst, unsigned Insn,
3486                          uint64_t Address, const void *Decoder) {
3487   DecodeStatus S = MCDisassembler::Success;
3488 
3489   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3490   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3491   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3492   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3493   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3494 
3495   unsigned align = 0;
3496   unsigned index = 0;
3497   unsigned inc = 1;
3498   switch (size) {
3499     default:
3500       return MCDisassembler::Fail;
3501     case 0:
3502       index = fieldFromInstruction32(Insn, 5, 3);
3503       if (fieldFromInstruction32(Insn, 4, 1))
3504         align = 2;
3505       break;
3506     case 1:
3507       index = fieldFromInstruction32(Insn, 6, 2);
3508       if (fieldFromInstruction32(Insn, 4, 1))
3509         align = 4;
3510       if (fieldFromInstruction32(Insn, 5, 1))
3511         inc = 2;
3512       break;
3513     case 2:
3514       if (fieldFromInstruction32(Insn, 5, 1))
3515         return MCDisassembler::Fail; // UNDEFINED
3516       index = fieldFromInstruction32(Insn, 7, 1);
3517       if (fieldFromInstruction32(Insn, 4, 1) != 0)
3518         align = 8;
3519       if (fieldFromInstruction32(Insn, 6, 1))
3520         inc = 2;
3521       break;
3522   }
3523 
3524   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3525     return MCDisassembler::Fail;
3526   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3527     return MCDisassembler::Fail;
3528   if (Rm != 0xF) { // Writeback
3529     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3530       return MCDisassembler::Fail;
3531   }
3532   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3533     return MCDisassembler::Fail;
3534   Inst.addOperand(MCOperand::CreateImm(align));
3535   if (Rm != 0xF) {
3536     if (Rm != 0xD) {
3537       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3538         return MCDisassembler::Fail;
3539     } else
3540       Inst.addOperand(MCOperand::CreateReg(0));
3541   }
3542 
3543   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3544     return MCDisassembler::Fail;
3545   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3546     return MCDisassembler::Fail;
3547   Inst.addOperand(MCOperand::CreateImm(index));
3548 
3549   return S;
3550 }
3551 
3552 static DecodeStatus DecodeVST2LN(llvm::MCInst &Inst, unsigned Insn,
3553                          uint64_t Address, const void *Decoder) {
3554   DecodeStatus S = MCDisassembler::Success;
3555 
3556   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3557   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3558   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3559   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3560   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3561 
3562   unsigned align = 0;
3563   unsigned index = 0;
3564   unsigned inc = 1;
3565   switch (size) {
3566     default:
3567       return MCDisassembler::Fail;
3568     case 0:
3569       index = fieldFromInstruction32(Insn, 5, 3);
3570       if (fieldFromInstruction32(Insn, 4, 1))
3571         align = 2;
3572       break;
3573     case 1:
3574       index = fieldFromInstruction32(Insn, 6, 2);
3575       if (fieldFromInstruction32(Insn, 4, 1))
3576         align = 4;
3577       if (fieldFromInstruction32(Insn, 5, 1))
3578         inc = 2;
3579       break;
3580     case 2:
3581       if (fieldFromInstruction32(Insn, 5, 1))
3582         return MCDisassembler::Fail; // UNDEFINED
3583       index = fieldFromInstruction32(Insn, 7, 1);
3584       if (fieldFromInstruction32(Insn, 4, 1) != 0)
3585         align = 8;
3586       if (fieldFromInstruction32(Insn, 6, 1))
3587         inc = 2;
3588       break;
3589   }
3590 
3591   if (Rm != 0xF) { // Writeback
3592     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3593       return MCDisassembler::Fail;
3594   }
3595   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3596     return MCDisassembler::Fail;
3597   Inst.addOperand(MCOperand::CreateImm(align));
3598   if (Rm != 0xF) {
3599     if (Rm != 0xD) {
3600       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3601         return MCDisassembler::Fail;
3602     } else
3603       Inst.addOperand(MCOperand::CreateReg(0));
3604   }
3605 
3606   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3607     return MCDisassembler::Fail;
3608   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3609     return MCDisassembler::Fail;
3610   Inst.addOperand(MCOperand::CreateImm(index));
3611 
3612   return S;
3613 }
3614 
3615 
3616 static DecodeStatus DecodeVLD3LN(llvm::MCInst &Inst, unsigned Insn,
3617                          uint64_t Address, const void *Decoder) {
3618   DecodeStatus S = MCDisassembler::Success;
3619 
3620   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3621   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3622   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3623   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3624   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3625 
3626   unsigned align = 0;
3627   unsigned index = 0;
3628   unsigned inc = 1;
3629   switch (size) {
3630     default:
3631       return MCDisassembler::Fail;
3632     case 0:
3633       if (fieldFromInstruction32(Insn, 4, 1))
3634         return MCDisassembler::Fail; // UNDEFINED
3635       index = fieldFromInstruction32(Insn, 5, 3);
3636       break;
3637     case 1:
3638       if (fieldFromInstruction32(Insn, 4, 1))
3639         return MCDisassembler::Fail; // UNDEFINED
3640       index = fieldFromInstruction32(Insn, 6, 2);
3641       if (fieldFromInstruction32(Insn, 5, 1))
3642         inc = 2;
3643       break;
3644     case 2:
3645       if (fieldFromInstruction32(Insn, 4, 2))
3646         return MCDisassembler::Fail; // UNDEFINED
3647       index = fieldFromInstruction32(Insn, 7, 1);
3648       if (fieldFromInstruction32(Insn, 6, 1))
3649         inc = 2;
3650       break;
3651   }
3652 
3653   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3654     return MCDisassembler::Fail;
3655   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3656     return MCDisassembler::Fail;
3657   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3658     return MCDisassembler::Fail;
3659 
3660   if (Rm != 0xF) { // Writeback
3661     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3662     return MCDisassembler::Fail;
3663   }
3664   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3665     return MCDisassembler::Fail;
3666   Inst.addOperand(MCOperand::CreateImm(align));
3667   if (Rm != 0xF) {
3668     if (Rm != 0xD) {
3669       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3670     return MCDisassembler::Fail;
3671     } else
3672       Inst.addOperand(MCOperand::CreateReg(0));
3673   }
3674 
3675   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3676     return MCDisassembler::Fail;
3677   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3678     return MCDisassembler::Fail;
3679   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3680     return MCDisassembler::Fail;
3681   Inst.addOperand(MCOperand::CreateImm(index));
3682 
3683   return S;
3684 }
3685 
3686 static DecodeStatus DecodeVST3LN(llvm::MCInst &Inst, unsigned Insn,
3687                          uint64_t Address, const void *Decoder) {
3688   DecodeStatus S = MCDisassembler::Success;
3689 
3690   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3691   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3692   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3693   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3694   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3695 
3696   unsigned align = 0;
3697   unsigned index = 0;
3698   unsigned inc = 1;
3699   switch (size) {
3700     default:
3701       return MCDisassembler::Fail;
3702     case 0:
3703       if (fieldFromInstruction32(Insn, 4, 1))
3704         return MCDisassembler::Fail; // UNDEFINED
3705       index = fieldFromInstruction32(Insn, 5, 3);
3706       break;
3707     case 1:
3708       if (fieldFromInstruction32(Insn, 4, 1))
3709         return MCDisassembler::Fail; // UNDEFINED
3710       index = fieldFromInstruction32(Insn, 6, 2);
3711       if (fieldFromInstruction32(Insn, 5, 1))
3712         inc = 2;
3713       break;
3714     case 2:
3715       if (fieldFromInstruction32(Insn, 4, 2))
3716         return MCDisassembler::Fail; // UNDEFINED
3717       index = fieldFromInstruction32(Insn, 7, 1);
3718       if (fieldFromInstruction32(Insn, 6, 1))
3719         inc = 2;
3720       break;
3721   }
3722 
3723   if (Rm != 0xF) { // Writeback
3724     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3725     return MCDisassembler::Fail;
3726   }
3727   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3728     return MCDisassembler::Fail;
3729   Inst.addOperand(MCOperand::CreateImm(align));
3730   if (Rm != 0xF) {
3731     if (Rm != 0xD) {
3732       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3733     return MCDisassembler::Fail;
3734     } else
3735       Inst.addOperand(MCOperand::CreateReg(0));
3736   }
3737 
3738   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3739     return MCDisassembler::Fail;
3740   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3741     return MCDisassembler::Fail;
3742   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3743     return MCDisassembler::Fail;
3744   Inst.addOperand(MCOperand::CreateImm(index));
3745 
3746   return S;
3747 }
3748 
3749 
3750 static DecodeStatus DecodeVLD4LN(llvm::MCInst &Inst, unsigned Insn,
3751                          uint64_t Address, const void *Decoder) {
3752   DecodeStatus S = MCDisassembler::Success;
3753 
3754   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3755   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3756   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3757   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3758   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3759 
3760   unsigned align = 0;
3761   unsigned index = 0;
3762   unsigned inc = 1;
3763   switch (size) {
3764     default:
3765       return MCDisassembler::Fail;
3766     case 0:
3767       if (fieldFromInstruction32(Insn, 4, 1))
3768         align = 4;
3769       index = fieldFromInstruction32(Insn, 5, 3);
3770       break;
3771     case 1:
3772       if (fieldFromInstruction32(Insn, 4, 1))
3773         align = 8;
3774       index = fieldFromInstruction32(Insn, 6, 2);
3775       if (fieldFromInstruction32(Insn, 5, 1))
3776         inc = 2;
3777       break;
3778     case 2:
3779       if (fieldFromInstruction32(Insn, 4, 2))
3780         align = 4 << fieldFromInstruction32(Insn, 4, 2);
3781       index = fieldFromInstruction32(Insn, 7, 1);
3782       if (fieldFromInstruction32(Insn, 6, 1))
3783         inc = 2;
3784       break;
3785   }
3786 
3787   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3788     return MCDisassembler::Fail;
3789   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3790     return MCDisassembler::Fail;
3791   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3792     return MCDisassembler::Fail;
3793   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
3794     return MCDisassembler::Fail;
3795 
3796   if (Rm != 0xF) { // Writeback
3797     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3798       return MCDisassembler::Fail;
3799   }
3800   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3801     return MCDisassembler::Fail;
3802   Inst.addOperand(MCOperand::CreateImm(align));
3803   if (Rm != 0xF) {
3804     if (Rm != 0xD) {
3805       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3806         return MCDisassembler::Fail;
3807     } else
3808       Inst.addOperand(MCOperand::CreateReg(0));
3809   }
3810 
3811   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3812     return MCDisassembler::Fail;
3813   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3814     return MCDisassembler::Fail;
3815   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3816     return MCDisassembler::Fail;
3817   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
3818     return MCDisassembler::Fail;
3819   Inst.addOperand(MCOperand::CreateImm(index));
3820 
3821   return S;
3822 }
3823 
3824 static DecodeStatus DecodeVST4LN(llvm::MCInst &Inst, unsigned Insn,
3825                          uint64_t Address, const void *Decoder) {
3826   DecodeStatus S = MCDisassembler::Success;
3827 
3828   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3829   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3830   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3831   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3832   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3833 
3834   unsigned align = 0;
3835   unsigned index = 0;
3836   unsigned inc = 1;
3837   switch (size) {
3838     default:
3839       return MCDisassembler::Fail;
3840     case 0:
3841       if (fieldFromInstruction32(Insn, 4, 1))
3842         align = 4;
3843       index = fieldFromInstruction32(Insn, 5, 3);
3844       break;
3845     case 1:
3846       if (fieldFromInstruction32(Insn, 4, 1))
3847         align = 8;
3848       index = fieldFromInstruction32(Insn, 6, 2);
3849       if (fieldFromInstruction32(Insn, 5, 1))
3850         inc = 2;
3851       break;
3852     case 2:
3853       if (fieldFromInstruction32(Insn, 4, 2))
3854         align = 4 << fieldFromInstruction32(Insn, 4, 2);
3855       index = fieldFromInstruction32(Insn, 7, 1);
3856       if (fieldFromInstruction32(Insn, 6, 1))
3857         inc = 2;
3858       break;
3859   }
3860 
3861   if (Rm != 0xF) { // Writeback
3862     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3863     return MCDisassembler::Fail;
3864   }
3865   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3866     return MCDisassembler::Fail;
3867   Inst.addOperand(MCOperand::CreateImm(align));
3868   if (Rm != 0xF) {
3869     if (Rm != 0xD) {
3870       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3871     return MCDisassembler::Fail;
3872     } else
3873       Inst.addOperand(MCOperand::CreateReg(0));
3874   }
3875 
3876   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3877     return MCDisassembler::Fail;
3878   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3879     return MCDisassembler::Fail;
3880   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3881     return MCDisassembler::Fail;
3882   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
3883     return MCDisassembler::Fail;
3884   Inst.addOperand(MCOperand::CreateImm(index));
3885 
3886   return S;
3887 }
3888 
3889 static DecodeStatus DecodeVMOVSRR(llvm::MCInst &Inst, unsigned Insn,
3890                                   uint64_t Address, const void *Decoder) {
3891   DecodeStatus S = MCDisassembler::Success;
3892   unsigned Rt  = fieldFromInstruction32(Insn, 12, 4);
3893   unsigned Rt2 = fieldFromInstruction32(Insn, 16, 4);
3894   unsigned Rm  = fieldFromInstruction32(Insn,  0, 4);
3895   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3896   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
3897 
3898   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
3899     S = MCDisassembler::SoftFail;
3900 
3901   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
3902     return MCDisassembler::Fail;
3903   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
3904     return MCDisassembler::Fail;
3905   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
3906     return MCDisassembler::Fail;
3907   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
3908     return MCDisassembler::Fail;
3909   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3910     return MCDisassembler::Fail;
3911 
3912   return S;
3913 }
3914 
3915 static DecodeStatus DecodeVMOVRRS(llvm::MCInst &Inst, unsigned Insn,
3916                                   uint64_t Address, const void *Decoder) {
3917   DecodeStatus S = MCDisassembler::Success;
3918   unsigned Rt  = fieldFromInstruction32(Insn, 12, 4);
3919   unsigned Rt2 = fieldFromInstruction32(Insn, 16, 4);
3920   unsigned Rm  = fieldFromInstruction32(Insn,  0, 4);
3921   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3922   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
3923 
3924   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
3925     S = MCDisassembler::SoftFail;
3926 
3927   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
3928     return MCDisassembler::Fail;
3929   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
3930     return MCDisassembler::Fail;
3931   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
3932     return MCDisassembler::Fail;
3933   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
3934     return MCDisassembler::Fail;
3935   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3936     return MCDisassembler::Fail;
3937 
3938   return S;
3939 }
3940 
3941 static DecodeStatus DecodeIT(llvm::MCInst &Inst, unsigned Insn,
3942                              uint64_t Address, const void *Decoder) {
3943   DecodeStatus S = MCDisassembler::Success;
3944   unsigned pred = fieldFromInstruction16(Insn, 4, 4);
3945   // The InstPrinter needs to have the low bit of the predicate in
3946   // the mask operand to be able to print it properly.
3947   unsigned mask = fieldFromInstruction16(Insn, 0, 5);
3948 
3949   if (pred == 0xF) {
3950     pred = 0xE;
3951     S = MCDisassembler::SoftFail;
3952   }
3953 
3954   if ((mask & 0xF) == 0) {
3955     // Preserve the high bit of the mask, which is the low bit of
3956     // the predicate.
3957     mask &= 0x10;
3958     mask |= 0x8;
3959     S = MCDisassembler::SoftFail;
3960   }
3961 
3962   Inst.addOperand(MCOperand::CreateImm(pred));
3963   Inst.addOperand(MCOperand::CreateImm(mask));
3964   return S;
3965 }
3966 
3967 static DecodeStatus
3968 DecodeT2LDRDPreInstruction(llvm::MCInst &Inst, unsigned Insn,
3969                            uint64_t Address, const void *Decoder) {
3970   DecodeStatus S = MCDisassembler::Success;
3971 
3972   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3973   unsigned Rt2 = fieldFromInstruction32(Insn, 8, 4);
3974   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3975   unsigned addr = fieldFromInstruction32(Insn, 0, 8);
3976   unsigned W = fieldFromInstruction32(Insn, 21, 1);
3977   unsigned U = fieldFromInstruction32(Insn, 23, 1);
3978   unsigned P = fieldFromInstruction32(Insn, 24, 1);
3979   bool writeback = (W == 1) | (P == 0);
3980 
3981   addr |= (U << 8) | (Rn << 9);
3982 
3983   if (writeback && (Rn == Rt || Rn == Rt2))
3984     Check(S, MCDisassembler::SoftFail);
3985   if (Rt == Rt2)
3986     Check(S, MCDisassembler::SoftFail);
3987 
3988   // Rt
3989   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
3990     return MCDisassembler::Fail;
3991   // Rt2
3992   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
3993     return MCDisassembler::Fail;
3994   // Writeback operand
3995   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
3996     return MCDisassembler::Fail;
3997   // addr
3998   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
3999     return MCDisassembler::Fail;
4000 
4001   return S;
4002 }
4003 
4004 static DecodeStatus
4005 DecodeT2STRDPreInstruction(llvm::MCInst &Inst, unsigned Insn,
4006                            uint64_t Address, const void *Decoder) {
4007   DecodeStatus S = MCDisassembler::Success;
4008 
4009   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
4010   unsigned Rt2 = fieldFromInstruction32(Insn, 8, 4);
4011   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
4012   unsigned addr = fieldFromInstruction32(Insn, 0, 8);
4013   unsigned W = fieldFromInstruction32(Insn, 21, 1);
4014   unsigned U = fieldFromInstruction32(Insn, 23, 1);
4015   unsigned P = fieldFromInstruction32(Insn, 24, 1);
4016   bool writeback = (W == 1) | (P == 0);
4017 
4018   addr |= (U << 8) | (Rn << 9);
4019 
4020   if (writeback && (Rn == Rt || Rn == Rt2))
4021     Check(S, MCDisassembler::SoftFail);
4022 
4023   // Writeback operand
4024   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
4025     return MCDisassembler::Fail;
4026   // Rt
4027   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
4028     return MCDisassembler::Fail;
4029   // Rt2
4030   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
4031     return MCDisassembler::Fail;
4032   // addr
4033   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
4034     return MCDisassembler::Fail;
4035 
4036   return S;
4037 }
4038 
4039 static DecodeStatus DecodeT2Adr(llvm::MCInst &Inst, uint32_t Insn,
4040                                 uint64_t Address, const void *Decoder) {
4041   unsigned sign1 = fieldFromInstruction32(Insn, 21, 1);
4042   unsigned sign2 = fieldFromInstruction32(Insn, 23, 1);
4043   if (sign1 != sign2) return MCDisassembler::Fail;
4044 
4045   unsigned Val = fieldFromInstruction32(Insn, 0, 8);
4046   Val |= fieldFromInstruction32(Insn, 12, 3) << 8;
4047   Val |= fieldFromInstruction32(Insn, 26, 1) << 11;
4048   Val |= sign1 << 12;
4049   Inst.addOperand(MCOperand::CreateImm(SignExtend32<13>(Val)));
4050 
4051   return MCDisassembler::Success;
4052 }
4053 
4054 static DecodeStatus DecodeT2ShifterImmOperand(llvm::MCInst &Inst, uint32_t Val,
4055                                               uint64_t Address,
4056                                               const void *Decoder) {
4057   DecodeStatus S = MCDisassembler::Success;
4058 
4059   // Shift of "asr #32" is not allowed in Thumb2 mode.
4060   if (Val == 0x20) S = MCDisassembler::SoftFail;
4061   Inst.addOperand(MCOperand::CreateImm(Val));
4062   return S;
4063 }
4064 
4065