xref: /llvm-project/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (revision f902d92fc91496fc821285d828db0ee45f05edef)
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/ARMBaseInfo.h"
17 #include "llvm/MC/EDInstInfo.h"
18 #include "llvm/MC/MCInst.h"
19 #include "llvm/MC/MCExpr.h"
20 #include "llvm/MC/MCContext.h"
21 #include "llvm/MC/MCDisassembler.h"
22 #include "llvm/Support/Debug.h"
23 #include "llvm/Support/MemoryObject.h"
24 #include "llvm/Support/ErrorHandling.h"
25 #include "llvm/Support/TargetRegistry.h"
26 #include "llvm/Support/raw_ostream.h"
27 
28 using namespace llvm;
29 
30 typedef MCDisassembler::DecodeStatus DecodeStatus;
31 
32 namespace {
33 /// ARMDisassembler - ARM disassembler for all ARM platforms.
34 class ARMDisassembler : public MCDisassembler {
35 public:
36   /// Constructor     - Initializes the disassembler.
37   ///
38   ARMDisassembler(const MCSubtargetInfo &STI) :
39     MCDisassembler(STI) {
40   }
41 
42   ~ARMDisassembler() {
43   }
44 
45   /// getInstruction - See MCDisassembler.
46   DecodeStatus getInstruction(MCInst &instr,
47                               uint64_t &size,
48                               const MemoryObject &region,
49                               uint64_t address,
50                               raw_ostream &vStream,
51                               raw_ostream &cStream) const;
52 
53   /// getEDInfo - See MCDisassembler.
54   EDInstInfo *getEDInfo() const;
55 private:
56 };
57 
58 /// ThumbDisassembler - Thumb disassembler for all Thumb platforms.
59 class ThumbDisassembler : public MCDisassembler {
60 public:
61   /// Constructor     - Initializes the disassembler.
62   ///
63   ThumbDisassembler(const MCSubtargetInfo &STI) :
64     MCDisassembler(STI) {
65   }
66 
67   ~ThumbDisassembler() {
68   }
69 
70   /// getInstruction - See MCDisassembler.
71   DecodeStatus getInstruction(MCInst &instr,
72                               uint64_t &size,
73                               const MemoryObject &region,
74                               uint64_t address,
75                               raw_ostream &vStream,
76                               raw_ostream &cStream) const;
77 
78   /// getEDInfo - See MCDisassembler.
79   EDInstInfo *getEDInfo() const;
80 private:
81   mutable std::vector<unsigned> ITBlock;
82   DecodeStatus AddThumbPredicate(MCInst&) const;
83   void UpdateThumbVFPPredicate(MCInst&) const;
84 };
85 }
86 
87 static bool Check(DecodeStatus &Out, DecodeStatus In) {
88   switch (In) {
89     case MCDisassembler::Success:
90       // Out stays the same.
91       return true;
92     case MCDisassembler::SoftFail:
93       Out = In;
94       return true;
95     case MCDisassembler::Fail:
96       Out = In;
97       return false;
98   }
99   return false;
100 }
101 
102 
103 // Forward declare these because the autogenerated code will reference them.
104 // Definitions are further down.
105 static DecodeStatus DecodeGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
106                                    uint64_t Address, const void *Decoder);
107 static DecodeStatus DecodeGPRnopcRegisterClass(llvm::MCInst &Inst,
108                                                unsigned RegNo, uint64_t Address,
109                                                const void *Decoder);
110 static DecodeStatus DecodetGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
111                                    uint64_t Address, const void *Decoder);
112 static DecodeStatus DecodetcGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
113                                    uint64_t Address, const void *Decoder);
114 static DecodeStatus DecoderGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
115                                    uint64_t Address, const void *Decoder);
116 static DecodeStatus DecodeSPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
117                                    uint64_t Address, const void *Decoder);
118 static DecodeStatus DecodeDPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
119                                    uint64_t Address, const void *Decoder);
120 static DecodeStatus DecodeDPR_8RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
121                                    uint64_t Address, const void *Decoder);
122 static DecodeStatus DecodeDPR_VFP2RegisterClass(llvm::MCInst &Inst,
123                                                 unsigned RegNo,
124                                                 uint64_t Address,
125                                                 const void *Decoder);
126 static DecodeStatus DecodeQPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
127                                    uint64_t Address, const void *Decoder);
128 
129 static DecodeStatus DecodePredicateOperand(llvm::MCInst &Inst, unsigned Val,
130                                uint64_t Address, const void *Decoder);
131 static DecodeStatus DecodeCCOutOperand(llvm::MCInst &Inst, unsigned Val,
132                                uint64_t Address, const void *Decoder);
133 static DecodeStatus DecodeSOImmOperand(llvm::MCInst &Inst, unsigned Val,
134                                uint64_t Address, const void *Decoder);
135 static DecodeStatus DecodeRegListOperand(llvm::MCInst &Inst, unsigned Val,
136                                uint64_t Address, const void *Decoder);
137 static DecodeStatus DecodeSPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
138                                uint64_t Address, const void *Decoder);
139 static DecodeStatus DecodeDPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
140                                uint64_t Address, const void *Decoder);
141 
142 static DecodeStatus DecodeBitfieldMaskOperand(llvm::MCInst &Inst, unsigned Insn,
143                                uint64_t Address, const void *Decoder);
144 static DecodeStatus DecodeCopMemInstruction(llvm::MCInst &Inst, unsigned Insn,
145                                uint64_t Address, const void *Decoder);
146 static DecodeStatus DecodeAddrMode2IdxInstruction(llvm::MCInst &Inst,
147                                                   unsigned Insn,
148                                                   uint64_t Address,
149                                                   const void *Decoder);
150 static DecodeStatus DecodeSORegMemOperand(llvm::MCInst &Inst, unsigned Insn,
151                                uint64_t Address, const void *Decoder);
152 static DecodeStatus DecodeAddrMode3Instruction(llvm::MCInst &Inst,unsigned Insn,
153                                uint64_t Address, const void *Decoder);
154 static DecodeStatus DecodeSORegImmOperand(llvm::MCInst &Inst, unsigned Insn,
155                                uint64_t Address, const void *Decoder);
156 static DecodeStatus DecodeSORegRegOperand(llvm::MCInst &Inst, unsigned Insn,
157                                uint64_t Address, const void *Decoder);
158 
159 static DecodeStatus DecodeMemMultipleWritebackInstruction(llvm::MCInst & Inst,
160                                                   unsigned Insn,
161                                                   uint64_t Adddress,
162                                                   const void *Decoder);
163 static DecodeStatus DecodeSMLAInstruction(llvm::MCInst &Inst, unsigned Insn,
164                                uint64_t Address, const void *Decoder);
165 static DecodeStatus DecodeCPSInstruction(llvm::MCInst &Inst, unsigned Insn,
166                                uint64_t Address, const void *Decoder);
167 static DecodeStatus DecodeT2CPSInstruction(llvm::MCInst &Inst, unsigned Insn,
168                                uint64_t Address, const void *Decoder);
169 static DecodeStatus DecodeAddrModeImm12Operand(llvm::MCInst &Inst, unsigned Val,
170                                uint64_t Address, const void *Decoder);
171 static DecodeStatus DecodeAddrMode5Operand(llvm::MCInst &Inst, unsigned Val,
172                                uint64_t Address, const void *Decoder);
173 static DecodeStatus DecodeAddrMode7Operand(llvm::MCInst &Inst, unsigned Val,
174                                uint64_t Address, const void *Decoder);
175 static DecodeStatus DecodeBranchImmInstruction(llvm::MCInst &Inst,unsigned Insn,
176                                uint64_t Address, const void *Decoder);
177 static DecodeStatus DecodeVCVTImmOperand(llvm::MCInst &Inst, unsigned Val,
178                                uint64_t Address, const void *Decoder);
179 static DecodeStatus DecodeAddrMode6Operand(llvm::MCInst &Inst, unsigned Val,
180                                uint64_t Address, const void *Decoder);
181 static DecodeStatus DecodeVLDInstruction(llvm::MCInst &Inst, unsigned Val,
182                                uint64_t Address, const void *Decoder);
183 static DecodeStatus DecodeVSTInstruction(llvm::MCInst &Inst, unsigned Val,
184                                uint64_t Address, const void *Decoder);
185 static DecodeStatus DecodeVLD1DupInstruction(llvm::MCInst &Inst, unsigned Val,
186                                uint64_t Address, const void *Decoder);
187 static DecodeStatus DecodeVLD2DupInstruction(llvm::MCInst &Inst, unsigned Val,
188                                uint64_t Address, const void *Decoder);
189 static DecodeStatus DecodeVLD3DupInstruction(llvm::MCInst &Inst, unsigned Val,
190                                uint64_t Address, const void *Decoder);
191 static DecodeStatus DecodeVLD4DupInstruction(llvm::MCInst &Inst, unsigned Val,
192                                uint64_t Address, const void *Decoder);
193 static DecodeStatus DecodeNEONModImmInstruction(llvm::MCInst &Inst,unsigned Val,
194                                uint64_t Address, const void *Decoder);
195 static DecodeStatus DecodeVSHLMaxInstruction(llvm::MCInst &Inst, unsigned Val,
196                                uint64_t Address, const void *Decoder);
197 static DecodeStatus DecodeShiftRight8Imm(llvm::MCInst &Inst, unsigned Val,
198                                uint64_t Address, const void *Decoder);
199 static DecodeStatus DecodeShiftRight16Imm(llvm::MCInst &Inst, unsigned Val,
200                                uint64_t Address, const void *Decoder);
201 static DecodeStatus DecodeShiftRight32Imm(llvm::MCInst &Inst, unsigned Val,
202                                uint64_t Address, const void *Decoder);
203 static DecodeStatus DecodeShiftRight64Imm(llvm::MCInst &Inst, unsigned Val,
204                                uint64_t Address, const void *Decoder);
205 static DecodeStatus DecodeTBLInstruction(llvm::MCInst &Inst, unsigned Insn,
206                                uint64_t Address, const void *Decoder);
207 static DecodeStatus DecodeVFPfpImm(llvm::MCInst &Inst, unsigned Val,
208                                uint64_t Address, const void *Decoder);
209 static DecodeStatus DecodePostIdxReg(llvm::MCInst &Inst, unsigned Insn,
210                                uint64_t Address, const void *Decoder);
211 static DecodeStatus DecodeCoprocessor(llvm::MCInst &Inst, unsigned Insn,
212                                uint64_t Address, const void *Decoder);
213 static DecodeStatus DecodeMemBarrierOption(llvm::MCInst &Inst, unsigned Insn,
214                                uint64_t Address, const void *Decoder);
215 static DecodeStatus DecodeMSRMask(llvm::MCInst &Inst, unsigned Insn,
216                                uint64_t Address, const void *Decoder);
217 static DecodeStatus DecodeDoubleRegLoad(llvm::MCInst &Inst, unsigned Insn,
218                                uint64_t Address, const void *Decoder);
219 static DecodeStatus DecodeDoubleRegStore(llvm::MCInst &Inst, unsigned Insn,
220                                uint64_t Address, const void *Decoder);
221 static DecodeStatus DecodeLDRPreImm(llvm::MCInst &Inst, unsigned Insn,
222                                uint64_t Address, const void *Decoder);
223 static DecodeStatus DecodeLDRPreReg(llvm::MCInst &Inst, unsigned Insn,
224                                uint64_t Address, const void *Decoder);
225 static DecodeStatus DecodeSTRPreImm(llvm::MCInst &Inst, unsigned Insn,
226                                uint64_t Address, const void *Decoder);
227 static DecodeStatus DecodeSTRPreReg(llvm::MCInst &Inst, unsigned Insn,
228                                uint64_t Address, const void *Decoder);
229 static DecodeStatus DecodeVLD1LN(llvm::MCInst &Inst, unsigned Insn,
230                                uint64_t Address, const void *Decoder);
231 static DecodeStatus DecodeVLD2LN(llvm::MCInst &Inst, unsigned Insn,
232                                uint64_t Address, const void *Decoder);
233 static DecodeStatus DecodeVLD3LN(llvm::MCInst &Inst, unsigned Insn,
234                                uint64_t Address, const void *Decoder);
235 static DecodeStatus DecodeVLD4LN(llvm::MCInst &Inst, unsigned Insn,
236                                uint64_t Address, const void *Decoder);
237 static DecodeStatus DecodeVST1LN(llvm::MCInst &Inst, unsigned Insn,
238                                uint64_t Address, const void *Decoder);
239 static DecodeStatus DecodeVST2LN(llvm::MCInst &Inst, unsigned Insn,
240                                uint64_t Address, const void *Decoder);
241 static DecodeStatus DecodeVST3LN(llvm::MCInst &Inst, unsigned Insn,
242                                uint64_t Address, const void *Decoder);
243 static DecodeStatus DecodeVST4LN(llvm::MCInst &Inst, unsigned Insn,
244                                uint64_t Address, const void *Decoder);
245 static DecodeStatus DecodeVMOVSRR(llvm::MCInst &Inst, unsigned Insn,
246                                uint64_t Address, const void *Decoder);
247 static DecodeStatus DecodeVMOVRRS(llvm::MCInst &Inst, unsigned Insn,
248                                uint64_t Address, const void *Decoder);
249 
250 static DecodeStatus DecodeThumbAddSpecialReg(llvm::MCInst &Inst, uint16_t Insn,
251                                uint64_t Address, const void *Decoder);
252 static DecodeStatus DecodeThumbBROperand(llvm::MCInst &Inst, unsigned Val,
253                                uint64_t Address, const void *Decoder);
254 static DecodeStatus DecodeT2BROperand(llvm::MCInst &Inst, unsigned Val,
255                                uint64_t Address, const void *Decoder);
256 static DecodeStatus DecodeThumbCmpBROperand(llvm::MCInst &Inst, unsigned Val,
257                                uint64_t Address, const void *Decoder);
258 static DecodeStatus DecodeThumbAddrModeRR(llvm::MCInst &Inst, unsigned Val,
259                                uint64_t Address, const void *Decoder);
260 static DecodeStatus DecodeThumbAddrModeIS(llvm::MCInst &Inst, unsigned Val,
261                                uint64_t Address, const void *Decoder);
262 static DecodeStatus DecodeThumbAddrModePC(llvm::MCInst &Inst, unsigned Val,
263                                uint64_t Address, const void *Decoder);
264 static DecodeStatus DecodeThumbAddrModeSP(llvm::MCInst &Inst, unsigned Val,
265                                uint64_t Address, const void *Decoder);
266 static DecodeStatus DecodeT2AddrModeSOReg(llvm::MCInst &Inst, unsigned Val,
267                                uint64_t Address, const void *Decoder);
268 static DecodeStatus DecodeT2LoadShift(llvm::MCInst &Inst, unsigned Val,
269                                uint64_t Address, const void *Decoder);
270 static DecodeStatus DecodeT2Imm8S4(llvm::MCInst &Inst, unsigned Val,
271                                uint64_t Address, const void *Decoder);
272 static DecodeStatus DecodeT2AddrModeImm8s4(llvm::MCInst &Inst, unsigned Val,
273                                uint64_t Address, const void *Decoder);
274 static DecodeStatus DecodeT2AddrModeImm0_1020s4(llvm::MCInst &Inst,unsigned Val,
275                                uint64_t Address, const void *Decoder);
276 static DecodeStatus DecodeT2Imm8(llvm::MCInst &Inst, unsigned Val,
277                                uint64_t Address, const void *Decoder);
278 static DecodeStatus DecodeT2AddrModeImm8(llvm::MCInst &Inst, unsigned Val,
279                                uint64_t Address, const void *Decoder);
280 static DecodeStatus DecodeThumbAddSPImm(llvm::MCInst &Inst, uint16_t Val,
281                                uint64_t Address, const void *Decoder);
282 static DecodeStatus DecodeThumbAddSPReg(llvm::MCInst &Inst, uint16_t Insn,
283                                 uint64_t Address, const void *Decoder);
284 static DecodeStatus DecodeThumbCPS(llvm::MCInst &Inst, uint16_t Insn,
285                                 uint64_t Address, const void *Decoder);
286 static DecodeStatus DecodeThumbBLXOffset(llvm::MCInst &Inst, unsigned Insn,
287                                 uint64_t Address, const void *Decoder);
288 static DecodeStatus DecodeT2AddrModeImm12(llvm::MCInst &Inst, unsigned Val,
289                                 uint64_t Address, const void *Decoder);
290 static DecodeStatus DecodeThumbTableBranch(llvm::MCInst &Inst, unsigned Val,
291                                 uint64_t Address, const void *Decoder);
292 static DecodeStatus DecodeThumb2BCCInstruction(llvm::MCInst &Inst, unsigned Val,
293                                 uint64_t Address, const void *Decoder);
294 static DecodeStatus DecodeT2SOImm(llvm::MCInst &Inst, unsigned Val,
295                                 uint64_t Address, const void *Decoder);
296 static DecodeStatus DecodeThumbBCCTargetOperand(llvm::MCInst &Inst,unsigned Val,
297                                 uint64_t Address, const void *Decoder);
298 static DecodeStatus DecodeThumbBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
299                                 uint64_t Address, const void *Decoder);
300 static DecodeStatus DecodeIT(llvm::MCInst &Inst, unsigned Val,
301                                 uint64_t Address, const void *Decoder);
302 static DecodeStatus DecodeT2LDRDPreInstruction(llvm::MCInst &Inst,unsigned Insn,
303                                uint64_t Address, const void *Decoder);
304 static DecodeStatus DecodeT2STRDPreInstruction(llvm::MCInst &Inst,unsigned Insn,
305                                uint64_t Address, const void *Decoder);
306 static DecodeStatus DecodeT2Adr(llvm::MCInst &Inst, unsigned Val,
307                                 uint64_t Address, const void *Decoder);
308 static DecodeStatus DecodeT2LdStPre(llvm::MCInst &Inst, unsigned Val,
309                                 uint64_t Address, const void *Decoder);
310 
311 
312 #include "ARMGenDisassemblerTables.inc"
313 #include "ARMGenInstrInfo.inc"
314 #include "ARMGenEDInfo.inc"
315 
316 static MCDisassembler *createARMDisassembler(const Target &T, const MCSubtargetInfo &STI) {
317   return new ARMDisassembler(STI);
318 }
319 
320 static MCDisassembler *createThumbDisassembler(const Target &T, const MCSubtargetInfo &STI) {
321   return new ThumbDisassembler(STI);
322 }
323 
324 EDInstInfo *ARMDisassembler::getEDInfo() const {
325   return instInfoARM;
326 }
327 
328 EDInstInfo *ThumbDisassembler::getEDInfo() const {
329   return instInfoARM;
330 }
331 
332 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
333                                              const MemoryObject &Region,
334                                              uint64_t Address,
335                                              raw_ostream &os,
336                                              raw_ostream &cs) const {
337   uint8_t bytes[4];
338 
339   assert(!(STI.getFeatureBits() & ARM::ModeThumb) &&
340          "Asked to disassemble an ARM instruction but Subtarget is in Thumb mode!");
341 
342   // We want to read exactly 4 bytes of data.
343   if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1) {
344     Size = 0;
345     return MCDisassembler::Fail;
346   }
347 
348   // Encoded as a small-endian 32-bit word in the stream.
349   uint32_t insn = (bytes[3] << 24) |
350                   (bytes[2] << 16) |
351                   (bytes[1] <<  8) |
352                   (bytes[0] <<  0);
353 
354   // Calling the auto-generated decoder function.
355   DecodeStatus result = decodeARMInstruction32(MI, insn, Address, this, STI);
356   if (result != MCDisassembler::Fail) {
357     Size = 4;
358     return result;
359   }
360 
361   // VFP and NEON instructions, similarly, are shared between ARM
362   // and Thumb modes.
363   MI.clear();
364   result = decodeVFPInstruction32(MI, insn, Address, this, STI);
365   if (result != MCDisassembler::Fail) {
366     Size = 4;
367     return result;
368   }
369 
370   MI.clear();
371   result = decodeNEONDataInstruction32(MI, insn, Address, this, STI);
372   if (result != MCDisassembler::Fail) {
373     Size = 4;
374     // Add a fake predicate operand, because we share these instruction
375     // definitions with Thumb2 where these instructions are predicable.
376     if (!DecodePredicateOperand(MI, 0xE, Address, this))
377       return MCDisassembler::Fail;
378     return result;
379   }
380 
381   MI.clear();
382   result = decodeNEONLoadStoreInstruction32(MI, insn, Address, this, STI);
383   if (result != MCDisassembler::Fail) {
384     Size = 4;
385     // Add a fake predicate operand, because we share these instruction
386     // definitions with Thumb2 where these instructions are predicable.
387     if (!DecodePredicateOperand(MI, 0xE, Address, this))
388       return MCDisassembler::Fail;
389     return result;
390   }
391 
392   MI.clear();
393   result = decodeNEONDupInstruction32(MI, insn, Address, this, STI);
394   if (result != MCDisassembler::Fail) {
395     Size = 4;
396     // Add a fake predicate operand, because we share these instruction
397     // definitions with Thumb2 where these instructions are predicable.
398     if (!DecodePredicateOperand(MI, 0xE, Address, this))
399       return MCDisassembler::Fail;
400     return result;
401   }
402 
403   MI.clear();
404 
405   Size = 0;
406   return MCDisassembler::Fail;
407 }
408 
409 namespace llvm {
410 extern MCInstrDesc ARMInsts[];
411 }
412 
413 // Thumb1 instructions don't have explicit S bits.  Rather, they
414 // implicitly set CPSR.  Since it's not represented in the encoding, the
415 // auto-generated decoder won't inject the CPSR operand.  We need to fix
416 // that as a post-pass.
417 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
418   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
419   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
420   MCInst::iterator I = MI.begin();
421   for (unsigned i = 0; i < NumOps; ++i, ++I) {
422     if (I == MI.end()) break;
423     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
424       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
425       MI.insert(I, MCOperand::CreateReg(InITBlock ? 0 : ARM::CPSR));
426       return;
427     }
428   }
429 
430   MI.insert(I, MCOperand::CreateReg(InITBlock ? 0 : ARM::CPSR));
431 }
432 
433 // Most Thumb instructions don't have explicit predicates in the
434 // encoding, but rather get their predicates from IT context.  We need
435 // to fix up the predicate operands using this context information as a
436 // post-pass.
437 MCDisassembler::DecodeStatus
438 ThumbDisassembler::AddThumbPredicate(MCInst &MI) const {
439   MCDisassembler::DecodeStatus S = Success;
440 
441   // A few instructions actually have predicates encoded in them.  Don't
442   // try to overwrite it if we're seeing one of those.
443   switch (MI.getOpcode()) {
444     case ARM::tBcc:
445     case ARM::t2Bcc:
446     case ARM::tCBZ:
447     case ARM::tCBNZ:
448       // Some instructions (mostly conditional branches) are not
449       // allowed in IT blocks.
450       if (!ITBlock.empty())
451         S = SoftFail;
452       else
453         return Success;
454       break;
455     case ARM::tB:
456     case ARM::t2B:
457     case ARM::t2TBB:
458     case ARM::t2TBH:
459       // Some instructions (mostly unconditional branches) can
460       // only appears at the end of, or outside of, an IT.
461       if (ITBlock.size() > 1)
462         S = SoftFail;
463       break;
464     default:
465       break;
466   }
467 
468   // If we're in an IT block, base the predicate on that.  Otherwise,
469   // assume a predicate of AL.
470   unsigned CC;
471   if (!ITBlock.empty()) {
472     CC = ITBlock.back();
473     if (CC == 0xF)
474       CC = ARMCC::AL;
475     ITBlock.pop_back();
476   } else
477     CC = ARMCC::AL;
478 
479   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
480   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
481   MCInst::iterator I = MI.begin();
482   for (unsigned i = 0; i < NumOps; ++i, ++I) {
483     if (I == MI.end()) break;
484     if (OpInfo[i].isPredicate()) {
485       I = MI.insert(I, MCOperand::CreateImm(CC));
486       ++I;
487       if (CC == ARMCC::AL)
488         MI.insert(I, MCOperand::CreateReg(0));
489       else
490         MI.insert(I, MCOperand::CreateReg(ARM::CPSR));
491       return S;
492     }
493   }
494 
495   I = MI.insert(I, MCOperand::CreateImm(CC));
496   ++I;
497   if (CC == ARMCC::AL)
498     MI.insert(I, MCOperand::CreateReg(0));
499   else
500     MI.insert(I, MCOperand::CreateReg(ARM::CPSR));
501 
502   return S;
503 }
504 
505 // Thumb VFP instructions are a special case.  Because we share their
506 // encodings between ARM and Thumb modes, and they are predicable in ARM
507 // mode, the auto-generated decoder will give them an (incorrect)
508 // predicate operand.  We need to rewrite these operands based on the IT
509 // context as a post-pass.
510 void ThumbDisassembler::UpdateThumbVFPPredicate(MCInst &MI) const {
511   unsigned CC;
512   if (!ITBlock.empty()) {
513     CC = ITBlock.back();
514     ITBlock.pop_back();
515   } else
516     CC = ARMCC::AL;
517 
518   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
519   MCInst::iterator I = MI.begin();
520   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
521   for (unsigned i = 0; i < NumOps; ++i, ++I) {
522     if (OpInfo[i].isPredicate() ) {
523       I->setImm(CC);
524       ++I;
525       if (CC == ARMCC::AL)
526         I->setReg(0);
527       else
528         I->setReg(ARM::CPSR);
529       return;
530     }
531   }
532 }
533 
534 DecodeStatus ThumbDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
535                                                const MemoryObject &Region,
536                                                uint64_t Address,
537                                                raw_ostream &os,
538                                                raw_ostream &cs) const {
539   uint8_t bytes[4];
540 
541   assert((STI.getFeatureBits() & ARM::ModeThumb) &&
542          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
543 
544   // We want to read exactly 2 bytes of data.
545   if (Region.readBytes(Address, 2, (uint8_t*)bytes, NULL) == -1) {
546     Size = 0;
547     return MCDisassembler::Fail;
548   }
549 
550   uint16_t insn16 = (bytes[1] << 8) | bytes[0];
551   DecodeStatus result = decodeThumbInstruction16(MI, insn16, Address, this, STI);
552   if (result != MCDisassembler::Fail) {
553     Size = 2;
554     Check(result, AddThumbPredicate(MI));
555     return result;
556   }
557 
558   MI.clear();
559   result = decodeThumbSBitInstruction16(MI, insn16, Address, this, STI);
560   if (result) {
561     Size = 2;
562     bool InITBlock = !ITBlock.empty();
563     Check(result, AddThumbPredicate(MI));
564     AddThumb1SBit(MI, InITBlock);
565     return result;
566   }
567 
568   MI.clear();
569   result = decodeThumb2Instruction16(MI, insn16, Address, this, STI);
570   if (result != MCDisassembler::Fail) {
571     Size = 2;
572     Check(result, AddThumbPredicate(MI));
573 
574     // If we find an IT instruction, we need to parse its condition
575     // code and mask operands so that we can apply them correctly
576     // to the subsequent instructions.
577     if (MI.getOpcode() == ARM::t2IT) {
578       // Nested IT blocks are UNPREDICTABLE.
579       if (!ITBlock.empty())
580         return MCDisassembler::SoftFail;
581 
582       // (3 - the number of trailing zeros) is the number of then / else.
583       unsigned firstcond = MI.getOperand(0).getImm();
584       unsigned Mask = MI.getOperand(1).getImm();
585       unsigned CondBit0 = Mask >> 4 & 1;
586       unsigned NumTZ = CountTrailingZeros_32(Mask);
587       assert(NumTZ <= 3 && "Invalid IT mask!");
588       for (unsigned Pos = 3, e = NumTZ; Pos > e; --Pos) {
589         bool T = ((Mask >> Pos) & 1) == CondBit0;
590         if (T)
591           ITBlock.insert(ITBlock.begin(), firstcond);
592         else
593           ITBlock.insert(ITBlock.begin(), firstcond ^ 1);
594       }
595 
596       ITBlock.push_back(firstcond);
597     }
598 
599     return result;
600   }
601 
602   // We want to read exactly 4 bytes of data.
603   if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1) {
604     Size = 0;
605     return MCDisassembler::Fail;
606   }
607 
608   uint32_t insn32 = (bytes[3] <<  8) |
609                     (bytes[2] <<  0) |
610                     (bytes[1] << 24) |
611                     (bytes[0] << 16);
612   MI.clear();
613   result = decodeThumbInstruction32(MI, insn32, Address, this, STI);
614   if (result != MCDisassembler::Fail) {
615     Size = 4;
616     bool InITBlock = ITBlock.size();
617     Check(result, AddThumbPredicate(MI));
618     AddThumb1SBit(MI, InITBlock);
619     return result;
620   }
621 
622   MI.clear();
623   result = decodeThumb2Instruction32(MI, insn32, Address, this, STI);
624   if (result != MCDisassembler::Fail) {
625     Size = 4;
626     Check(result, AddThumbPredicate(MI));
627     return result;
628   }
629 
630   MI.clear();
631   result = decodeVFPInstruction32(MI, insn32, Address, this, STI);
632   if (result != MCDisassembler::Fail) {
633     Size = 4;
634     UpdateThumbVFPPredicate(MI);
635     return result;
636   }
637 
638   MI.clear();
639   result = decodeNEONDupInstruction32(MI, insn32, Address, this, STI);
640   if (result != MCDisassembler::Fail) {
641     Size = 4;
642     Check(result, AddThumbPredicate(MI));
643     return result;
644   }
645 
646   if (fieldFromInstruction32(insn32, 24, 8) == 0xF9) {
647     MI.clear();
648     uint32_t NEONLdStInsn = insn32;
649     NEONLdStInsn &= 0xF0FFFFFF;
650     NEONLdStInsn |= 0x04000000;
651     result = decodeNEONLoadStoreInstruction32(MI, NEONLdStInsn, Address, this, STI);
652     if (result != MCDisassembler::Fail) {
653       Size = 4;
654       Check(result, AddThumbPredicate(MI));
655       return result;
656     }
657   }
658 
659   if (fieldFromInstruction32(insn32, 24, 4) == 0xF) {
660     MI.clear();
661     uint32_t NEONDataInsn = insn32;
662     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
663     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
664     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
665     result = decodeNEONDataInstruction32(MI, NEONDataInsn, Address, this, STI);
666     if (result != MCDisassembler::Fail) {
667       Size = 4;
668       Check(result, AddThumbPredicate(MI));
669       return result;
670     }
671   }
672 
673   Size = 0;
674   return MCDisassembler::Fail;
675 }
676 
677 
678 extern "C" void LLVMInitializeARMDisassembler() {
679   TargetRegistry::RegisterMCDisassembler(TheARMTarget,
680                                          createARMDisassembler);
681   TargetRegistry::RegisterMCDisassembler(TheThumbTarget,
682                                          createThumbDisassembler);
683 }
684 
685 static const unsigned GPRDecoderTable[] = {
686   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
687   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
688   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
689   ARM::R12, ARM::SP, ARM::LR, ARM::PC
690 };
691 
692 static DecodeStatus DecodeGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
693                                    uint64_t Address, const void *Decoder) {
694   if (RegNo > 15)
695     return MCDisassembler::Fail;
696 
697   unsigned Register = GPRDecoderTable[RegNo];
698   Inst.addOperand(MCOperand::CreateReg(Register));
699   return MCDisassembler::Success;
700 }
701 
702 static DecodeStatus
703 DecodeGPRnopcRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
704                            uint64_t Address, const void *Decoder) {
705   if (RegNo == 15) return MCDisassembler::Fail;
706   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
707 }
708 
709 static DecodeStatus DecodetGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
710                                    uint64_t Address, const void *Decoder) {
711   if (RegNo > 7)
712     return MCDisassembler::Fail;
713   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
714 }
715 
716 static DecodeStatus DecodetcGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
717                                    uint64_t Address, const void *Decoder) {
718   unsigned Register = 0;
719   switch (RegNo) {
720     case 0:
721       Register = ARM::R0;
722       break;
723     case 1:
724       Register = ARM::R1;
725       break;
726     case 2:
727       Register = ARM::R2;
728       break;
729     case 3:
730       Register = ARM::R3;
731       break;
732     case 9:
733       Register = ARM::R9;
734       break;
735     case 12:
736       Register = ARM::R12;
737       break;
738     default:
739       return MCDisassembler::Fail;
740     }
741 
742   Inst.addOperand(MCOperand::CreateReg(Register));
743   return MCDisassembler::Success;
744 }
745 
746 static DecodeStatus DecoderGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
747                                    uint64_t Address, const void *Decoder) {
748   if (RegNo == 13 || RegNo == 15) return MCDisassembler::Fail;
749   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
750 }
751 
752 static const unsigned SPRDecoderTable[] = {
753      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
754      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
755      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
756     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
757     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
758     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
759     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
760     ARM::S28, ARM::S29, ARM::S30, ARM::S31
761 };
762 
763 static DecodeStatus DecodeSPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
764                                    uint64_t Address, const void *Decoder) {
765   if (RegNo > 31)
766     return MCDisassembler::Fail;
767 
768   unsigned Register = SPRDecoderTable[RegNo];
769   Inst.addOperand(MCOperand::CreateReg(Register));
770   return MCDisassembler::Success;
771 }
772 
773 static const unsigned DPRDecoderTable[] = {
774      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
775      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
776      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
777     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
778     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
779     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
780     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
781     ARM::D28, ARM::D29, ARM::D30, ARM::D31
782 };
783 
784 static DecodeStatus DecodeDPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
785                                    uint64_t Address, const void *Decoder) {
786   if (RegNo > 31)
787     return MCDisassembler::Fail;
788 
789   unsigned Register = DPRDecoderTable[RegNo];
790   Inst.addOperand(MCOperand::CreateReg(Register));
791   return MCDisassembler::Success;
792 }
793 
794 static DecodeStatus DecodeDPR_8RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
795                                    uint64_t Address, const void *Decoder) {
796   if (RegNo > 7)
797     return MCDisassembler::Fail;
798   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
799 }
800 
801 static DecodeStatus
802 DecodeDPR_VFP2RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
803                             uint64_t Address, const void *Decoder) {
804   if (RegNo > 15)
805     return MCDisassembler::Fail;
806   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
807 }
808 
809 static const unsigned QPRDecoderTable[] = {
810      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
811      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
812      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
813     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
814 };
815 
816 
817 static DecodeStatus DecodeQPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
818                                    uint64_t Address, const void *Decoder) {
819   if (RegNo > 31)
820     return MCDisassembler::Fail;
821   RegNo >>= 1;
822 
823   unsigned Register = QPRDecoderTable[RegNo];
824   Inst.addOperand(MCOperand::CreateReg(Register));
825   return MCDisassembler::Success;
826 }
827 
828 static DecodeStatus DecodePredicateOperand(llvm::MCInst &Inst, unsigned Val,
829                                uint64_t Address, const void *Decoder) {
830   if (Val == 0xF) return MCDisassembler::Fail;
831   // AL predicate is not allowed on Thumb1 branches.
832   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
833     return MCDisassembler::Fail;
834   Inst.addOperand(MCOperand::CreateImm(Val));
835   if (Val == ARMCC::AL) {
836     Inst.addOperand(MCOperand::CreateReg(0));
837   } else
838     Inst.addOperand(MCOperand::CreateReg(ARM::CPSR));
839   return MCDisassembler::Success;
840 }
841 
842 static DecodeStatus DecodeCCOutOperand(llvm::MCInst &Inst, unsigned Val,
843                                uint64_t Address, const void *Decoder) {
844   if (Val)
845     Inst.addOperand(MCOperand::CreateReg(ARM::CPSR));
846   else
847     Inst.addOperand(MCOperand::CreateReg(0));
848   return MCDisassembler::Success;
849 }
850 
851 static DecodeStatus DecodeSOImmOperand(llvm::MCInst &Inst, unsigned Val,
852                                uint64_t Address, const void *Decoder) {
853   uint32_t imm = Val & 0xFF;
854   uint32_t rot = (Val & 0xF00) >> 7;
855   uint32_t rot_imm = (imm >> rot) | (imm << (32-rot));
856   Inst.addOperand(MCOperand::CreateImm(rot_imm));
857   return MCDisassembler::Success;
858 }
859 
860 static DecodeStatus DecodeSORegImmOperand(llvm::MCInst &Inst, unsigned Val,
861                                uint64_t Address, const void *Decoder) {
862   DecodeStatus S = MCDisassembler::Success;
863 
864   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
865   unsigned type = fieldFromInstruction32(Val, 5, 2);
866   unsigned imm = fieldFromInstruction32(Val, 7, 5);
867 
868   // Register-immediate
869   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
870     return MCDisassembler::Fail;
871 
872   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
873   switch (type) {
874     case 0:
875       Shift = ARM_AM::lsl;
876       break;
877     case 1:
878       Shift = ARM_AM::lsr;
879       break;
880     case 2:
881       Shift = ARM_AM::asr;
882       break;
883     case 3:
884       Shift = ARM_AM::ror;
885       break;
886   }
887 
888   if (Shift == ARM_AM::ror && imm == 0)
889     Shift = ARM_AM::rrx;
890 
891   unsigned Op = Shift | (imm << 3);
892   Inst.addOperand(MCOperand::CreateImm(Op));
893 
894   return S;
895 }
896 
897 static DecodeStatus DecodeSORegRegOperand(llvm::MCInst &Inst, unsigned Val,
898                                uint64_t Address, const void *Decoder) {
899   DecodeStatus S = MCDisassembler::Success;
900 
901   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
902   unsigned type = fieldFromInstruction32(Val, 5, 2);
903   unsigned Rs = fieldFromInstruction32(Val, 8, 4);
904 
905   // Register-register
906   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
907     return MCDisassembler::Fail;
908   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
909     return MCDisassembler::Fail;
910 
911   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
912   switch (type) {
913     case 0:
914       Shift = ARM_AM::lsl;
915       break;
916     case 1:
917       Shift = ARM_AM::lsr;
918       break;
919     case 2:
920       Shift = ARM_AM::asr;
921       break;
922     case 3:
923       Shift = ARM_AM::ror;
924       break;
925   }
926 
927   Inst.addOperand(MCOperand::CreateImm(Shift));
928 
929   return S;
930 }
931 
932 static DecodeStatus DecodeRegListOperand(llvm::MCInst &Inst, unsigned Val,
933                                  uint64_t Address, const void *Decoder) {
934   DecodeStatus S = MCDisassembler::Success;
935 
936   bool writebackLoad = false;
937   unsigned writebackReg = 0;
938   switch (Inst.getOpcode()) {
939     default:
940       break;
941     case ARM::LDMIA_UPD:
942     case ARM::LDMDB_UPD:
943     case ARM::LDMIB_UPD:
944     case ARM::LDMDA_UPD:
945     case ARM::t2LDMIA_UPD:
946     case ARM::t2LDMDB_UPD:
947       writebackLoad = true;
948       writebackReg = Inst.getOperand(0).getReg();
949       break;
950   }
951 
952   // Empty register lists are not allowed.
953   if (CountPopulation_32(Val) == 0) return MCDisassembler::Fail;
954   for (unsigned i = 0; i < 16; ++i) {
955     if (Val & (1 << i)) {
956       if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
957         return MCDisassembler::Fail;
958       // Writeback not allowed if Rn is in the target list.
959       if (writebackLoad && writebackReg == Inst.end()[-1].getReg())
960         Check(S, MCDisassembler::SoftFail);
961     }
962   }
963 
964   return S;
965 }
966 
967 static DecodeStatus DecodeSPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
968                                  uint64_t Address, const void *Decoder) {
969   DecodeStatus S = MCDisassembler::Success;
970 
971   unsigned Vd = fieldFromInstruction32(Val, 8, 4);
972   unsigned regs = Val & 0xFF;
973 
974   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
975     return MCDisassembler::Fail;
976   for (unsigned i = 0; i < (regs - 1); ++i) {
977     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
978       return MCDisassembler::Fail;
979   }
980 
981   return S;
982 }
983 
984 static DecodeStatus DecodeDPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
985                                  uint64_t Address, const void *Decoder) {
986   DecodeStatus S = MCDisassembler::Success;
987 
988   unsigned Vd = fieldFromInstruction32(Val, 8, 4);
989   unsigned regs = (Val & 0xFF) / 2;
990 
991   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
992       return MCDisassembler::Fail;
993   for (unsigned i = 0; i < (regs - 1); ++i) {
994     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
995       return MCDisassembler::Fail;
996   }
997 
998   return S;
999 }
1000 
1001 static DecodeStatus DecodeBitfieldMaskOperand(llvm::MCInst &Inst, unsigned Val,
1002                                       uint64_t Address, const void *Decoder) {
1003   // This operand encodes a mask of contiguous zeros between a specified MSB
1004   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1005   // the mask of all bits LSB-and-lower, and then xor them to create
1006   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1007   // create the final mask.
1008   unsigned msb = fieldFromInstruction32(Val, 5, 5);
1009   unsigned lsb = fieldFromInstruction32(Val, 0, 5);
1010 
1011   DecodeStatus S = MCDisassembler::Success;
1012   if (lsb > msb) Check(S, MCDisassembler::SoftFail);
1013 
1014   uint32_t msb_mask = 0xFFFFFFFF;
1015   if (msb != 31) msb_mask = (1U << (msb+1)) - 1;
1016   uint32_t lsb_mask = (1U << lsb) - 1;
1017 
1018   Inst.addOperand(MCOperand::CreateImm(~(msb_mask ^ lsb_mask)));
1019   return S;
1020 }
1021 
1022 static DecodeStatus DecodeCopMemInstruction(llvm::MCInst &Inst, unsigned Insn,
1023                                   uint64_t Address, const void *Decoder) {
1024   DecodeStatus S = MCDisassembler::Success;
1025 
1026   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1027   unsigned CRd = fieldFromInstruction32(Insn, 12, 4);
1028   unsigned coproc = fieldFromInstruction32(Insn, 8, 4);
1029   unsigned imm = fieldFromInstruction32(Insn, 0, 8);
1030   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1031   unsigned U = fieldFromInstruction32(Insn, 23, 1);
1032 
1033   switch (Inst.getOpcode()) {
1034     case ARM::LDC_OFFSET:
1035     case ARM::LDC_PRE:
1036     case ARM::LDC_POST:
1037     case ARM::LDC_OPTION:
1038     case ARM::LDCL_OFFSET:
1039     case ARM::LDCL_PRE:
1040     case ARM::LDCL_POST:
1041     case ARM::LDCL_OPTION:
1042     case ARM::STC_OFFSET:
1043     case ARM::STC_PRE:
1044     case ARM::STC_POST:
1045     case ARM::STC_OPTION:
1046     case ARM::STCL_OFFSET:
1047     case ARM::STCL_PRE:
1048     case ARM::STCL_POST:
1049     case ARM::STCL_OPTION:
1050     case ARM::t2LDC_OFFSET:
1051     case ARM::t2LDC_PRE:
1052     case ARM::t2LDC_POST:
1053     case ARM::t2LDC_OPTION:
1054     case ARM::t2LDCL_OFFSET:
1055     case ARM::t2LDCL_PRE:
1056     case ARM::t2LDCL_POST:
1057     case ARM::t2LDCL_OPTION:
1058     case ARM::t2STC_OFFSET:
1059     case ARM::t2STC_PRE:
1060     case ARM::t2STC_POST:
1061     case ARM::t2STC_OPTION:
1062     case ARM::t2STCL_OFFSET:
1063     case ARM::t2STCL_PRE:
1064     case ARM::t2STCL_POST:
1065     case ARM::t2STCL_OPTION:
1066       if (coproc == 0xA || coproc == 0xB)
1067         return MCDisassembler::Fail;
1068       break;
1069     default:
1070       break;
1071   }
1072 
1073   Inst.addOperand(MCOperand::CreateImm(coproc));
1074   Inst.addOperand(MCOperand::CreateImm(CRd));
1075   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1076     return MCDisassembler::Fail;
1077   switch (Inst.getOpcode()) {
1078     case ARM::LDC_OPTION:
1079     case ARM::LDCL_OPTION:
1080     case ARM::LDC2_OPTION:
1081     case ARM::LDC2L_OPTION:
1082     case ARM::STC_OPTION:
1083     case ARM::STCL_OPTION:
1084     case ARM::STC2_OPTION:
1085     case ARM::STC2L_OPTION:
1086     case ARM::LDCL_POST:
1087     case ARM::STCL_POST:
1088     case ARM::LDC2L_POST:
1089     case ARM::STC2L_POST:
1090     case ARM::t2LDC_OPTION:
1091     case ARM::t2LDCL_OPTION:
1092     case ARM::t2STC_OPTION:
1093     case ARM::t2STCL_OPTION:
1094     case ARM::t2LDCL_POST:
1095     case ARM::t2STCL_POST:
1096       break;
1097     default:
1098       Inst.addOperand(MCOperand::CreateReg(0));
1099       break;
1100   }
1101 
1102   unsigned P = fieldFromInstruction32(Insn, 24, 1);
1103   unsigned W = fieldFromInstruction32(Insn, 21, 1);
1104 
1105   bool writeback = (P == 0) || (W == 1);
1106   unsigned idx_mode = 0;
1107   if (P && writeback)
1108     idx_mode = ARMII::IndexModePre;
1109   else if (!P && writeback)
1110     idx_mode = ARMII::IndexModePost;
1111 
1112   switch (Inst.getOpcode()) {
1113     case ARM::LDCL_POST:
1114     case ARM::STCL_POST:
1115     case ARM::t2LDCL_POST:
1116     case ARM::t2STCL_POST:
1117     case ARM::LDC2L_POST:
1118     case ARM::STC2L_POST:
1119       imm |= U << 8;
1120     case ARM::LDC_OPTION:
1121     case ARM::LDCL_OPTION:
1122     case ARM::LDC2_OPTION:
1123     case ARM::LDC2L_OPTION:
1124     case ARM::STC_OPTION:
1125     case ARM::STCL_OPTION:
1126     case ARM::STC2_OPTION:
1127     case ARM::STC2L_OPTION:
1128     case ARM::t2LDC_OPTION:
1129     case ARM::t2LDCL_OPTION:
1130     case ARM::t2STC_OPTION:
1131     case ARM::t2STCL_OPTION:
1132       Inst.addOperand(MCOperand::CreateImm(imm));
1133       break;
1134     default:
1135       if (U)
1136         Inst.addOperand(MCOperand::CreateImm(
1137             ARM_AM::getAM2Opc(ARM_AM::add, imm, ARM_AM::lsl, idx_mode)));
1138       else
1139         Inst.addOperand(MCOperand::CreateImm(
1140             ARM_AM::getAM2Opc(ARM_AM::sub, imm, ARM_AM::lsl, idx_mode)));
1141       break;
1142   }
1143 
1144   switch (Inst.getOpcode()) {
1145     case ARM::LDC_OFFSET:
1146     case ARM::LDC_PRE:
1147     case ARM::LDC_POST:
1148     case ARM::LDC_OPTION:
1149     case ARM::LDCL_OFFSET:
1150     case ARM::LDCL_PRE:
1151     case ARM::LDCL_POST:
1152     case ARM::LDCL_OPTION:
1153     case ARM::STC_OFFSET:
1154     case ARM::STC_PRE:
1155     case ARM::STC_POST:
1156     case ARM::STC_OPTION:
1157     case ARM::STCL_OFFSET:
1158     case ARM::STCL_PRE:
1159     case ARM::STCL_POST:
1160     case ARM::STCL_OPTION:
1161       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1162         return MCDisassembler::Fail;
1163       break;
1164     default:
1165       break;
1166   }
1167 
1168   return S;
1169 }
1170 
1171 static DecodeStatus
1172 DecodeAddrMode2IdxInstruction(llvm::MCInst &Inst, unsigned Insn,
1173                               uint64_t Address, const void *Decoder) {
1174   DecodeStatus S = MCDisassembler::Success;
1175 
1176   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1177   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
1178   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1179   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
1180   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1181   unsigned reg = fieldFromInstruction32(Insn, 25, 1);
1182   unsigned P = fieldFromInstruction32(Insn, 24, 1);
1183   unsigned W = fieldFromInstruction32(Insn, 21, 1);
1184 
1185   // On stores, the writeback operand precedes Rt.
1186   switch (Inst.getOpcode()) {
1187     case ARM::STR_POST_IMM:
1188     case ARM::STR_POST_REG:
1189     case ARM::STRB_POST_IMM:
1190     case ARM::STRB_POST_REG:
1191     case ARM::STRT_POST_REG:
1192     case ARM::STRT_POST_IMM:
1193     case ARM::STRBT_POST_REG:
1194     case ARM::STRBT_POST_IMM:
1195       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1196         return MCDisassembler::Fail;
1197       break;
1198     default:
1199       break;
1200   }
1201 
1202   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1203     return MCDisassembler::Fail;
1204 
1205   // On loads, the writeback operand comes after Rt.
1206   switch (Inst.getOpcode()) {
1207     case ARM::LDR_POST_IMM:
1208     case ARM::LDR_POST_REG:
1209     case ARM::LDRB_POST_IMM:
1210     case ARM::LDRB_POST_REG:
1211     case ARM::LDRBT_POST_REG:
1212     case ARM::LDRBT_POST_IMM:
1213     case ARM::LDRT_POST_REG:
1214     case ARM::LDRT_POST_IMM:
1215       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1216         return MCDisassembler::Fail;
1217       break;
1218     default:
1219       break;
1220   }
1221 
1222   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1223     return MCDisassembler::Fail;
1224 
1225   ARM_AM::AddrOpc Op = ARM_AM::add;
1226   if (!fieldFromInstruction32(Insn, 23, 1))
1227     Op = ARM_AM::sub;
1228 
1229   bool writeback = (P == 0) || (W == 1);
1230   unsigned idx_mode = 0;
1231   if (P && writeback)
1232     idx_mode = ARMII::IndexModePre;
1233   else if (!P && writeback)
1234     idx_mode = ARMII::IndexModePost;
1235 
1236   if (writeback && (Rn == 15 || Rn == Rt))
1237     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1238 
1239   if (reg) {
1240     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1241       return MCDisassembler::Fail;
1242     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1243     switch( fieldFromInstruction32(Insn, 5, 2)) {
1244       case 0:
1245         Opc = ARM_AM::lsl;
1246         break;
1247       case 1:
1248         Opc = ARM_AM::lsr;
1249         break;
1250       case 2:
1251         Opc = ARM_AM::asr;
1252         break;
1253       case 3:
1254         Opc = ARM_AM::ror;
1255         break;
1256       default:
1257         return MCDisassembler::Fail;
1258     }
1259     unsigned amt = fieldFromInstruction32(Insn, 7, 5);
1260     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1261 
1262     Inst.addOperand(MCOperand::CreateImm(imm));
1263   } else {
1264     Inst.addOperand(MCOperand::CreateReg(0));
1265     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1266     Inst.addOperand(MCOperand::CreateImm(tmp));
1267   }
1268 
1269   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1270     return MCDisassembler::Fail;
1271 
1272   return S;
1273 }
1274 
1275 static DecodeStatus DecodeSORegMemOperand(llvm::MCInst &Inst, unsigned Val,
1276                                   uint64_t Address, const void *Decoder) {
1277   DecodeStatus S = MCDisassembler::Success;
1278 
1279   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
1280   unsigned Rm = fieldFromInstruction32(Val,  0, 4);
1281   unsigned type = fieldFromInstruction32(Val, 5, 2);
1282   unsigned imm = fieldFromInstruction32(Val, 7, 5);
1283   unsigned U = fieldFromInstruction32(Val, 12, 1);
1284 
1285   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1286   switch (type) {
1287     case 0:
1288       ShOp = ARM_AM::lsl;
1289       break;
1290     case 1:
1291       ShOp = ARM_AM::lsr;
1292       break;
1293     case 2:
1294       ShOp = ARM_AM::asr;
1295       break;
1296     case 3:
1297       ShOp = ARM_AM::ror;
1298       break;
1299   }
1300 
1301   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1302     return MCDisassembler::Fail;
1303   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1304     return MCDisassembler::Fail;
1305   unsigned shift;
1306   if (U)
1307     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1308   else
1309     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1310   Inst.addOperand(MCOperand::CreateImm(shift));
1311 
1312   return S;
1313 }
1314 
1315 static DecodeStatus
1316 DecodeAddrMode3Instruction(llvm::MCInst &Inst, unsigned Insn,
1317                            uint64_t Address, const void *Decoder) {
1318   DecodeStatus S = MCDisassembler::Success;
1319 
1320   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
1321   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1322   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1323   unsigned type = fieldFromInstruction32(Insn, 22, 1);
1324   unsigned imm = fieldFromInstruction32(Insn, 8, 4);
1325   unsigned U = ((~fieldFromInstruction32(Insn, 23, 1)) & 1) << 8;
1326   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1327   unsigned W = fieldFromInstruction32(Insn, 21, 1);
1328   unsigned P = fieldFromInstruction32(Insn, 24, 1);
1329 
1330   bool writeback = (W == 1) | (P == 0);
1331 
1332   // For {LD,ST}RD, Rt must be even, else undefined.
1333   switch (Inst.getOpcode()) {
1334     case ARM::STRD:
1335     case ARM::STRD_PRE:
1336     case ARM::STRD_POST:
1337     case ARM::LDRD:
1338     case ARM::LDRD_PRE:
1339     case ARM::LDRD_POST:
1340       if (Rt & 0x1) return MCDisassembler::Fail;
1341       break;
1342     default:
1343       break;
1344   }
1345 
1346   if (writeback) { // Writeback
1347     if (P)
1348       U |= ARMII::IndexModePre << 9;
1349     else
1350       U |= ARMII::IndexModePost << 9;
1351 
1352     // On stores, the writeback operand precedes Rt.
1353     switch (Inst.getOpcode()) {
1354     case ARM::STRD:
1355     case ARM::STRD_PRE:
1356     case ARM::STRD_POST:
1357     case ARM::STRH:
1358     case ARM::STRH_PRE:
1359     case ARM::STRH_POST:
1360       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1361         return MCDisassembler::Fail;
1362       break;
1363     default:
1364       break;
1365     }
1366   }
1367 
1368   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1369     return MCDisassembler::Fail;
1370   switch (Inst.getOpcode()) {
1371     case ARM::STRD:
1372     case ARM::STRD_PRE:
1373     case ARM::STRD_POST:
1374     case ARM::LDRD:
1375     case ARM::LDRD_PRE:
1376     case ARM::LDRD_POST:
1377       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
1378         return MCDisassembler::Fail;
1379       break;
1380     default:
1381       break;
1382   }
1383 
1384   if (writeback) {
1385     // On loads, the writeback operand comes after Rt.
1386     switch (Inst.getOpcode()) {
1387     case ARM::LDRD:
1388     case ARM::LDRD_PRE:
1389     case ARM::LDRD_POST:
1390     case ARM::LDRH:
1391     case ARM::LDRH_PRE:
1392     case ARM::LDRH_POST:
1393     case ARM::LDRSH:
1394     case ARM::LDRSH_PRE:
1395     case ARM::LDRSH_POST:
1396     case ARM::LDRSB:
1397     case ARM::LDRSB_PRE:
1398     case ARM::LDRSB_POST:
1399     case ARM::LDRHTr:
1400     case ARM::LDRSBTr:
1401       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1402         return MCDisassembler::Fail;
1403       break;
1404     default:
1405       break;
1406     }
1407   }
1408 
1409   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1410     return MCDisassembler::Fail;
1411 
1412   if (type) {
1413     Inst.addOperand(MCOperand::CreateReg(0));
1414     Inst.addOperand(MCOperand::CreateImm(U | (imm << 4) | Rm));
1415   } else {
1416     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1417     return MCDisassembler::Fail;
1418     Inst.addOperand(MCOperand::CreateImm(U));
1419   }
1420 
1421   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1422     return MCDisassembler::Fail;
1423 
1424   return S;
1425 }
1426 
1427 static DecodeStatus DecodeRFEInstruction(llvm::MCInst &Inst, unsigned Insn,
1428                                  uint64_t Address, const void *Decoder) {
1429   DecodeStatus S = MCDisassembler::Success;
1430 
1431   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1432   unsigned mode = fieldFromInstruction32(Insn, 23, 2);
1433 
1434   switch (mode) {
1435     case 0:
1436       mode = ARM_AM::da;
1437       break;
1438     case 1:
1439       mode = ARM_AM::ia;
1440       break;
1441     case 2:
1442       mode = ARM_AM::db;
1443       break;
1444     case 3:
1445       mode = ARM_AM::ib;
1446       break;
1447   }
1448 
1449   Inst.addOperand(MCOperand::CreateImm(mode));
1450   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1451     return MCDisassembler::Fail;
1452 
1453   return S;
1454 }
1455 
1456 static DecodeStatus DecodeMemMultipleWritebackInstruction(llvm::MCInst &Inst,
1457                                   unsigned Insn,
1458                                   uint64_t Address, const void *Decoder) {
1459   DecodeStatus S = MCDisassembler::Success;
1460 
1461   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1462   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1463   unsigned reglist = fieldFromInstruction32(Insn, 0, 16);
1464 
1465   if (pred == 0xF) {
1466     switch (Inst.getOpcode()) {
1467       case ARM::LDMDA:
1468         Inst.setOpcode(ARM::RFEDA);
1469         break;
1470       case ARM::LDMDA_UPD:
1471         Inst.setOpcode(ARM::RFEDA_UPD);
1472         break;
1473       case ARM::LDMDB:
1474         Inst.setOpcode(ARM::RFEDB);
1475         break;
1476       case ARM::LDMDB_UPD:
1477         Inst.setOpcode(ARM::RFEDB_UPD);
1478         break;
1479       case ARM::LDMIA:
1480         Inst.setOpcode(ARM::RFEIA);
1481         break;
1482       case ARM::LDMIA_UPD:
1483         Inst.setOpcode(ARM::RFEIA_UPD);
1484         break;
1485       case ARM::LDMIB:
1486         Inst.setOpcode(ARM::RFEIB);
1487         break;
1488       case ARM::LDMIB_UPD:
1489         Inst.setOpcode(ARM::RFEIB_UPD);
1490         break;
1491       case ARM::STMDA:
1492         Inst.setOpcode(ARM::SRSDA);
1493         break;
1494       case ARM::STMDA_UPD:
1495         Inst.setOpcode(ARM::SRSDA_UPD);
1496         break;
1497       case ARM::STMDB:
1498         Inst.setOpcode(ARM::SRSDB);
1499         break;
1500       case ARM::STMDB_UPD:
1501         Inst.setOpcode(ARM::SRSDB_UPD);
1502         break;
1503       case ARM::STMIA:
1504         Inst.setOpcode(ARM::SRSIA);
1505         break;
1506       case ARM::STMIA_UPD:
1507         Inst.setOpcode(ARM::SRSIA_UPD);
1508         break;
1509       case ARM::STMIB:
1510         Inst.setOpcode(ARM::SRSIB);
1511         break;
1512       case ARM::STMIB_UPD:
1513         Inst.setOpcode(ARM::SRSIB_UPD);
1514         break;
1515       default:
1516         if (!Check(S, MCDisassembler::Fail)) return MCDisassembler::Fail;
1517     }
1518 
1519     // For stores (which become SRS's, the only operand is the mode.
1520     if (fieldFromInstruction32(Insn, 20, 1) == 0) {
1521       Inst.addOperand(
1522           MCOperand::CreateImm(fieldFromInstruction32(Insn, 0, 4)));
1523       return S;
1524     }
1525 
1526     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
1527   }
1528 
1529   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1530     return MCDisassembler::Fail;
1531   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1532     return MCDisassembler::Fail; // Tied
1533   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1534     return MCDisassembler::Fail;
1535   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
1536     return MCDisassembler::Fail;
1537 
1538   return S;
1539 }
1540 
1541 static DecodeStatus DecodeCPSInstruction(llvm::MCInst &Inst, unsigned Insn,
1542                                  uint64_t Address, const void *Decoder) {
1543   unsigned imod = fieldFromInstruction32(Insn, 18, 2);
1544   unsigned M = fieldFromInstruction32(Insn, 17, 1);
1545   unsigned iflags = fieldFromInstruction32(Insn, 6, 3);
1546   unsigned mode = fieldFromInstruction32(Insn, 0, 5);
1547 
1548   DecodeStatus S = MCDisassembler::Success;
1549 
1550   // imod == '01' --> UNPREDICTABLE
1551   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
1552   // return failure here.  The '01' imod value is unprintable, so there's
1553   // nothing useful we could do even if we returned UNPREDICTABLE.
1554 
1555   if (imod == 1) return MCDisassembler::Fail;
1556 
1557   if (imod && M) {
1558     Inst.setOpcode(ARM::CPS3p);
1559     Inst.addOperand(MCOperand::CreateImm(imod));
1560     Inst.addOperand(MCOperand::CreateImm(iflags));
1561     Inst.addOperand(MCOperand::CreateImm(mode));
1562   } else if (imod && !M) {
1563     Inst.setOpcode(ARM::CPS2p);
1564     Inst.addOperand(MCOperand::CreateImm(imod));
1565     Inst.addOperand(MCOperand::CreateImm(iflags));
1566     if (mode) S = MCDisassembler::SoftFail;
1567   } else if (!imod && M) {
1568     Inst.setOpcode(ARM::CPS1p);
1569     Inst.addOperand(MCOperand::CreateImm(mode));
1570     if (iflags) S = MCDisassembler::SoftFail;
1571   } else {
1572     // imod == '00' && M == '0' --> UNPREDICTABLE
1573     Inst.setOpcode(ARM::CPS1p);
1574     Inst.addOperand(MCOperand::CreateImm(mode));
1575     S = MCDisassembler::SoftFail;
1576   }
1577 
1578   return S;
1579 }
1580 
1581 static DecodeStatus DecodeT2CPSInstruction(llvm::MCInst &Inst, unsigned Insn,
1582                                  uint64_t Address, const void *Decoder) {
1583   unsigned imod = fieldFromInstruction32(Insn, 9, 2);
1584   unsigned M = fieldFromInstruction32(Insn, 8, 1);
1585   unsigned iflags = fieldFromInstruction32(Insn, 5, 3);
1586   unsigned mode = fieldFromInstruction32(Insn, 0, 5);
1587 
1588   DecodeStatus S = MCDisassembler::Success;
1589 
1590   // imod == '01' --> UNPREDICTABLE
1591   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
1592   // return failure here.  The '01' imod value is unprintable, so there's
1593   // nothing useful we could do even if we returned UNPREDICTABLE.
1594 
1595   if (imod == 1) return MCDisassembler::Fail;
1596 
1597   if (imod && M) {
1598     Inst.setOpcode(ARM::t2CPS3p);
1599     Inst.addOperand(MCOperand::CreateImm(imod));
1600     Inst.addOperand(MCOperand::CreateImm(iflags));
1601     Inst.addOperand(MCOperand::CreateImm(mode));
1602   } else if (imod && !M) {
1603     Inst.setOpcode(ARM::t2CPS2p);
1604     Inst.addOperand(MCOperand::CreateImm(imod));
1605     Inst.addOperand(MCOperand::CreateImm(iflags));
1606     if (mode) S = MCDisassembler::SoftFail;
1607   } else if (!imod && M) {
1608     Inst.setOpcode(ARM::t2CPS1p);
1609     Inst.addOperand(MCOperand::CreateImm(mode));
1610     if (iflags) S = MCDisassembler::SoftFail;
1611   } else {
1612     // imod == '00' && M == '0' --> UNPREDICTABLE
1613     Inst.setOpcode(ARM::t2CPS1p);
1614     Inst.addOperand(MCOperand::CreateImm(mode));
1615     S = MCDisassembler::SoftFail;
1616   }
1617 
1618   return S;
1619 }
1620 
1621 
1622 static DecodeStatus DecodeSMLAInstruction(llvm::MCInst &Inst, unsigned Insn,
1623                                  uint64_t Address, const void *Decoder) {
1624   DecodeStatus S = MCDisassembler::Success;
1625 
1626   unsigned Rd = fieldFromInstruction32(Insn, 16, 4);
1627   unsigned Rn = fieldFromInstruction32(Insn, 0, 4);
1628   unsigned Rm = fieldFromInstruction32(Insn, 8, 4);
1629   unsigned Ra = fieldFromInstruction32(Insn, 12, 4);
1630   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1631 
1632   if (pred == 0xF)
1633     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
1634 
1635   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
1636     return MCDisassembler::Fail;
1637   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
1638     return MCDisassembler::Fail;
1639   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1640     return MCDisassembler::Fail;
1641   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
1642     return MCDisassembler::Fail;
1643 
1644   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1645     return MCDisassembler::Fail;
1646 
1647   return S;
1648 }
1649 
1650 static DecodeStatus DecodeAddrModeImm12Operand(llvm::MCInst &Inst, unsigned Val,
1651                            uint64_t Address, const void *Decoder) {
1652   DecodeStatus S = MCDisassembler::Success;
1653 
1654   unsigned add = fieldFromInstruction32(Val, 12, 1);
1655   unsigned imm = fieldFromInstruction32(Val, 0, 12);
1656   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
1657 
1658   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1659     return MCDisassembler::Fail;
1660 
1661   if (!add) imm *= -1;
1662   if (imm == 0 && !add) imm = INT32_MIN;
1663   Inst.addOperand(MCOperand::CreateImm(imm));
1664 
1665   return S;
1666 }
1667 
1668 static DecodeStatus DecodeAddrMode5Operand(llvm::MCInst &Inst, unsigned Val,
1669                                    uint64_t Address, const void *Decoder) {
1670   DecodeStatus S = MCDisassembler::Success;
1671 
1672   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
1673   unsigned U = fieldFromInstruction32(Val, 8, 1);
1674   unsigned imm = fieldFromInstruction32(Val, 0, 8);
1675 
1676   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1677     return MCDisassembler::Fail;
1678 
1679   if (U)
1680     Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
1681   else
1682     Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
1683 
1684   return S;
1685 }
1686 
1687 static DecodeStatus DecodeAddrMode7Operand(llvm::MCInst &Inst, unsigned Val,
1688                                    uint64_t Address, const void *Decoder) {
1689   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
1690 }
1691 
1692 static DecodeStatus
1693 DecodeBranchImmInstruction(llvm::MCInst &Inst, unsigned Insn,
1694                            uint64_t Address, const void *Decoder) {
1695   DecodeStatus S = MCDisassembler::Success;
1696 
1697   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1698   unsigned imm = fieldFromInstruction32(Insn, 0, 24) << 2;
1699 
1700   if (pred == 0xF) {
1701     Inst.setOpcode(ARM::BLXi);
1702     imm |= fieldFromInstruction32(Insn, 24, 1) << 1;
1703     Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1704     return S;
1705   }
1706 
1707   Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1708   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1709     return MCDisassembler::Fail;
1710 
1711   return S;
1712 }
1713 
1714 
1715 static DecodeStatus DecodeVCVTImmOperand(llvm::MCInst &Inst, unsigned Val,
1716                                  uint64_t Address, const void *Decoder) {
1717   Inst.addOperand(MCOperand::CreateImm(64 - Val));
1718   return MCDisassembler::Success;
1719 }
1720 
1721 static DecodeStatus DecodeAddrMode6Operand(llvm::MCInst &Inst, unsigned Val,
1722                                    uint64_t Address, const void *Decoder) {
1723   DecodeStatus S = MCDisassembler::Success;
1724 
1725   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
1726   unsigned align = fieldFromInstruction32(Val, 4, 2);
1727 
1728   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1729     return MCDisassembler::Fail;
1730   if (!align)
1731     Inst.addOperand(MCOperand::CreateImm(0));
1732   else
1733     Inst.addOperand(MCOperand::CreateImm(4 << align));
1734 
1735   return S;
1736 }
1737 
1738 static DecodeStatus DecodeVLDInstruction(llvm::MCInst &Inst, unsigned Insn,
1739                                    uint64_t Address, const void *Decoder) {
1740   DecodeStatus S = MCDisassembler::Success;
1741 
1742   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1743   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1744   unsigned wb = fieldFromInstruction32(Insn, 16, 4);
1745   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1746   Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
1747   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1748 
1749   // First output register
1750   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
1751     return MCDisassembler::Fail;
1752 
1753   // Second output register
1754   switch (Inst.getOpcode()) {
1755     case ARM::VLD1q8:
1756     case ARM::VLD1q16:
1757     case ARM::VLD1q32:
1758     case ARM::VLD1q64:
1759     case ARM::VLD1q8_UPD:
1760     case ARM::VLD1q16_UPD:
1761     case ARM::VLD1q32_UPD:
1762     case ARM::VLD1q64_UPD:
1763     case ARM::VLD1d8T:
1764     case ARM::VLD1d16T:
1765     case ARM::VLD1d32T:
1766     case ARM::VLD1d64T:
1767     case ARM::VLD1d8T_UPD:
1768     case ARM::VLD1d16T_UPD:
1769     case ARM::VLD1d32T_UPD:
1770     case ARM::VLD1d64T_UPD:
1771     case ARM::VLD1d8Q:
1772     case ARM::VLD1d16Q:
1773     case ARM::VLD1d32Q:
1774     case ARM::VLD1d64Q:
1775     case ARM::VLD1d8Q_UPD:
1776     case ARM::VLD1d16Q_UPD:
1777     case ARM::VLD1d32Q_UPD:
1778     case ARM::VLD1d64Q_UPD:
1779     case ARM::VLD2d8:
1780     case ARM::VLD2d16:
1781     case ARM::VLD2d32:
1782     case ARM::VLD2d8_UPD:
1783     case ARM::VLD2d16_UPD:
1784     case ARM::VLD2d32_UPD:
1785     case ARM::VLD2q8:
1786     case ARM::VLD2q16:
1787     case ARM::VLD2q32:
1788     case ARM::VLD2q8_UPD:
1789     case ARM::VLD2q16_UPD:
1790     case ARM::VLD2q32_UPD:
1791     case ARM::VLD3d8:
1792     case ARM::VLD3d16:
1793     case ARM::VLD3d32:
1794     case ARM::VLD3d8_UPD:
1795     case ARM::VLD3d16_UPD:
1796     case ARM::VLD3d32_UPD:
1797     case ARM::VLD4d8:
1798     case ARM::VLD4d16:
1799     case ARM::VLD4d32:
1800     case ARM::VLD4d8_UPD:
1801     case ARM::VLD4d16_UPD:
1802     case ARM::VLD4d32_UPD:
1803       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
1804         return MCDisassembler::Fail;
1805       break;
1806     case ARM::VLD2b8:
1807     case ARM::VLD2b16:
1808     case ARM::VLD2b32:
1809     case ARM::VLD2b8_UPD:
1810     case ARM::VLD2b16_UPD:
1811     case ARM::VLD2b32_UPD:
1812     case ARM::VLD3q8:
1813     case ARM::VLD3q16:
1814     case ARM::VLD3q32:
1815     case ARM::VLD3q8_UPD:
1816     case ARM::VLD3q16_UPD:
1817     case ARM::VLD3q32_UPD:
1818     case ARM::VLD4q8:
1819     case ARM::VLD4q16:
1820     case ARM::VLD4q32:
1821     case ARM::VLD4q8_UPD:
1822     case ARM::VLD4q16_UPD:
1823     case ARM::VLD4q32_UPD:
1824       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
1825         return MCDisassembler::Fail;
1826     default:
1827       break;
1828   }
1829 
1830   // Third output register
1831   switch(Inst.getOpcode()) {
1832     case ARM::VLD1d8T:
1833     case ARM::VLD1d16T:
1834     case ARM::VLD1d32T:
1835     case ARM::VLD1d64T:
1836     case ARM::VLD1d8T_UPD:
1837     case ARM::VLD1d16T_UPD:
1838     case ARM::VLD1d32T_UPD:
1839     case ARM::VLD1d64T_UPD:
1840     case ARM::VLD1d8Q:
1841     case ARM::VLD1d16Q:
1842     case ARM::VLD1d32Q:
1843     case ARM::VLD1d64Q:
1844     case ARM::VLD1d8Q_UPD:
1845     case ARM::VLD1d16Q_UPD:
1846     case ARM::VLD1d32Q_UPD:
1847     case ARM::VLD1d64Q_UPD:
1848     case ARM::VLD2q8:
1849     case ARM::VLD2q16:
1850     case ARM::VLD2q32:
1851     case ARM::VLD2q8_UPD:
1852     case ARM::VLD2q16_UPD:
1853     case ARM::VLD2q32_UPD:
1854     case ARM::VLD3d8:
1855     case ARM::VLD3d16:
1856     case ARM::VLD3d32:
1857     case ARM::VLD3d8_UPD:
1858     case ARM::VLD3d16_UPD:
1859     case ARM::VLD3d32_UPD:
1860     case ARM::VLD4d8:
1861     case ARM::VLD4d16:
1862     case ARM::VLD4d32:
1863     case ARM::VLD4d8_UPD:
1864     case ARM::VLD4d16_UPD:
1865     case ARM::VLD4d32_UPD:
1866       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
1867         return MCDisassembler::Fail;
1868       break;
1869     case ARM::VLD3q8:
1870     case ARM::VLD3q16:
1871     case ARM::VLD3q32:
1872     case ARM::VLD3q8_UPD:
1873     case ARM::VLD3q16_UPD:
1874     case ARM::VLD3q32_UPD:
1875     case ARM::VLD4q8:
1876     case ARM::VLD4q16:
1877     case ARM::VLD4q32:
1878     case ARM::VLD4q8_UPD:
1879     case ARM::VLD4q16_UPD:
1880     case ARM::VLD4q32_UPD:
1881       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
1882         return MCDisassembler::Fail;
1883       break;
1884     default:
1885       break;
1886   }
1887 
1888   // Fourth output register
1889   switch (Inst.getOpcode()) {
1890     case ARM::VLD1d8Q:
1891     case ARM::VLD1d16Q:
1892     case ARM::VLD1d32Q:
1893     case ARM::VLD1d64Q:
1894     case ARM::VLD1d8Q_UPD:
1895     case ARM::VLD1d16Q_UPD:
1896     case ARM::VLD1d32Q_UPD:
1897     case ARM::VLD1d64Q_UPD:
1898     case ARM::VLD2q8:
1899     case ARM::VLD2q16:
1900     case ARM::VLD2q32:
1901     case ARM::VLD2q8_UPD:
1902     case ARM::VLD2q16_UPD:
1903     case ARM::VLD2q32_UPD:
1904     case ARM::VLD4d8:
1905     case ARM::VLD4d16:
1906     case ARM::VLD4d32:
1907     case ARM::VLD4d8_UPD:
1908     case ARM::VLD4d16_UPD:
1909     case ARM::VLD4d32_UPD:
1910       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
1911         return MCDisassembler::Fail;
1912       break;
1913     case ARM::VLD4q8:
1914     case ARM::VLD4q16:
1915     case ARM::VLD4q32:
1916     case ARM::VLD4q8_UPD:
1917     case ARM::VLD4q16_UPD:
1918     case ARM::VLD4q32_UPD:
1919       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
1920         return MCDisassembler::Fail;
1921       break;
1922     default:
1923       break;
1924   }
1925 
1926   // Writeback operand
1927   switch (Inst.getOpcode()) {
1928     case ARM::VLD1d8_UPD:
1929     case ARM::VLD1d16_UPD:
1930     case ARM::VLD1d32_UPD:
1931     case ARM::VLD1d64_UPD:
1932     case ARM::VLD1q8_UPD:
1933     case ARM::VLD1q16_UPD:
1934     case ARM::VLD1q32_UPD:
1935     case ARM::VLD1q64_UPD:
1936     case ARM::VLD1d8T_UPD:
1937     case ARM::VLD1d16T_UPD:
1938     case ARM::VLD1d32T_UPD:
1939     case ARM::VLD1d64T_UPD:
1940     case ARM::VLD1d8Q_UPD:
1941     case ARM::VLD1d16Q_UPD:
1942     case ARM::VLD1d32Q_UPD:
1943     case ARM::VLD1d64Q_UPD:
1944     case ARM::VLD2d8_UPD:
1945     case ARM::VLD2d16_UPD:
1946     case ARM::VLD2d32_UPD:
1947     case ARM::VLD2q8_UPD:
1948     case ARM::VLD2q16_UPD:
1949     case ARM::VLD2q32_UPD:
1950     case ARM::VLD2b8_UPD:
1951     case ARM::VLD2b16_UPD:
1952     case ARM::VLD2b32_UPD:
1953     case ARM::VLD3d8_UPD:
1954     case ARM::VLD3d16_UPD:
1955     case ARM::VLD3d32_UPD:
1956     case ARM::VLD3q8_UPD:
1957     case ARM::VLD3q16_UPD:
1958     case ARM::VLD3q32_UPD:
1959     case ARM::VLD4d8_UPD:
1960     case ARM::VLD4d16_UPD:
1961     case ARM::VLD4d32_UPD:
1962     case ARM::VLD4q8_UPD:
1963     case ARM::VLD4q16_UPD:
1964     case ARM::VLD4q32_UPD:
1965       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
1966         return MCDisassembler::Fail;
1967       break;
1968     default:
1969       break;
1970   }
1971 
1972   // AddrMode6 Base (register+alignment)
1973   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
1974     return MCDisassembler::Fail;
1975 
1976   // AddrMode6 Offset (register)
1977   if (Rm == 0xD)
1978     Inst.addOperand(MCOperand::CreateReg(0));
1979   else if (Rm != 0xF) {
1980     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1981       return MCDisassembler::Fail;
1982   }
1983 
1984   return S;
1985 }
1986 
1987 static DecodeStatus DecodeVSTInstruction(llvm::MCInst &Inst, unsigned Insn,
1988                                  uint64_t Address, const void *Decoder) {
1989   DecodeStatus S = MCDisassembler::Success;
1990 
1991   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1992   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1993   unsigned wb = fieldFromInstruction32(Insn, 16, 4);
1994   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1995   Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
1996   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1997 
1998   // Writeback Operand
1999   switch (Inst.getOpcode()) {
2000     case ARM::VST1d8_UPD:
2001     case ARM::VST1d16_UPD:
2002     case ARM::VST1d32_UPD:
2003     case ARM::VST1d64_UPD:
2004     case ARM::VST1q8_UPD:
2005     case ARM::VST1q16_UPD:
2006     case ARM::VST1q32_UPD:
2007     case ARM::VST1q64_UPD:
2008     case ARM::VST1d8T_UPD:
2009     case ARM::VST1d16T_UPD:
2010     case ARM::VST1d32T_UPD:
2011     case ARM::VST1d64T_UPD:
2012     case ARM::VST1d8Q_UPD:
2013     case ARM::VST1d16Q_UPD:
2014     case ARM::VST1d32Q_UPD:
2015     case ARM::VST1d64Q_UPD:
2016     case ARM::VST2d8_UPD:
2017     case ARM::VST2d16_UPD:
2018     case ARM::VST2d32_UPD:
2019     case ARM::VST2q8_UPD:
2020     case ARM::VST2q16_UPD:
2021     case ARM::VST2q32_UPD:
2022     case ARM::VST2b8_UPD:
2023     case ARM::VST2b16_UPD:
2024     case ARM::VST2b32_UPD:
2025     case ARM::VST3d8_UPD:
2026     case ARM::VST3d16_UPD:
2027     case ARM::VST3d32_UPD:
2028     case ARM::VST3q8_UPD:
2029     case ARM::VST3q16_UPD:
2030     case ARM::VST3q32_UPD:
2031     case ARM::VST4d8_UPD:
2032     case ARM::VST4d16_UPD:
2033     case ARM::VST4d32_UPD:
2034     case ARM::VST4q8_UPD:
2035     case ARM::VST4q16_UPD:
2036     case ARM::VST4q32_UPD:
2037       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2038         return MCDisassembler::Fail;
2039       break;
2040     default:
2041       break;
2042   }
2043 
2044   // AddrMode6 Base (register+alignment)
2045   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2046     return MCDisassembler::Fail;
2047 
2048   // AddrMode6 Offset (register)
2049   if (Rm == 0xD)
2050     Inst.addOperand(MCOperand::CreateReg(0));
2051   else if (Rm != 0xF) {
2052     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2053     return MCDisassembler::Fail;
2054   }
2055 
2056   // First input register
2057   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2058     return MCDisassembler::Fail;
2059 
2060   // Second input register
2061   switch (Inst.getOpcode()) {
2062     case ARM::VST1q8:
2063     case ARM::VST1q16:
2064     case ARM::VST1q32:
2065     case ARM::VST1q64:
2066     case ARM::VST1q8_UPD:
2067     case ARM::VST1q16_UPD:
2068     case ARM::VST1q32_UPD:
2069     case ARM::VST1q64_UPD:
2070     case ARM::VST1d8T:
2071     case ARM::VST1d16T:
2072     case ARM::VST1d32T:
2073     case ARM::VST1d64T:
2074     case ARM::VST1d8T_UPD:
2075     case ARM::VST1d16T_UPD:
2076     case ARM::VST1d32T_UPD:
2077     case ARM::VST1d64T_UPD:
2078     case ARM::VST1d8Q:
2079     case ARM::VST1d16Q:
2080     case ARM::VST1d32Q:
2081     case ARM::VST1d64Q:
2082     case ARM::VST1d8Q_UPD:
2083     case ARM::VST1d16Q_UPD:
2084     case ARM::VST1d32Q_UPD:
2085     case ARM::VST1d64Q_UPD:
2086     case ARM::VST2d8:
2087     case ARM::VST2d16:
2088     case ARM::VST2d32:
2089     case ARM::VST2d8_UPD:
2090     case ARM::VST2d16_UPD:
2091     case ARM::VST2d32_UPD:
2092     case ARM::VST2q8:
2093     case ARM::VST2q16:
2094     case ARM::VST2q32:
2095     case ARM::VST2q8_UPD:
2096     case ARM::VST2q16_UPD:
2097     case ARM::VST2q32_UPD:
2098     case ARM::VST3d8:
2099     case ARM::VST3d16:
2100     case ARM::VST3d32:
2101     case ARM::VST3d8_UPD:
2102     case ARM::VST3d16_UPD:
2103     case ARM::VST3d32_UPD:
2104     case ARM::VST4d8:
2105     case ARM::VST4d16:
2106     case ARM::VST4d32:
2107     case ARM::VST4d8_UPD:
2108     case ARM::VST4d16_UPD:
2109     case ARM::VST4d32_UPD:
2110       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2111         return MCDisassembler::Fail;
2112       break;
2113     case ARM::VST2b8:
2114     case ARM::VST2b16:
2115     case ARM::VST2b32:
2116     case ARM::VST2b8_UPD:
2117     case ARM::VST2b16_UPD:
2118     case ARM::VST2b32_UPD:
2119     case ARM::VST3q8:
2120     case ARM::VST3q16:
2121     case ARM::VST3q32:
2122     case ARM::VST3q8_UPD:
2123     case ARM::VST3q16_UPD:
2124     case ARM::VST3q32_UPD:
2125     case ARM::VST4q8:
2126     case ARM::VST4q16:
2127     case ARM::VST4q32:
2128     case ARM::VST4q8_UPD:
2129     case ARM::VST4q16_UPD:
2130     case ARM::VST4q32_UPD:
2131       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2132         return MCDisassembler::Fail;
2133       break;
2134     default:
2135       break;
2136   }
2137 
2138   // Third input register
2139   switch (Inst.getOpcode()) {
2140     case ARM::VST1d8T:
2141     case ARM::VST1d16T:
2142     case ARM::VST1d32T:
2143     case ARM::VST1d64T:
2144     case ARM::VST1d8T_UPD:
2145     case ARM::VST1d16T_UPD:
2146     case ARM::VST1d32T_UPD:
2147     case ARM::VST1d64T_UPD:
2148     case ARM::VST1d8Q:
2149     case ARM::VST1d16Q:
2150     case ARM::VST1d32Q:
2151     case ARM::VST1d64Q:
2152     case ARM::VST1d8Q_UPD:
2153     case ARM::VST1d16Q_UPD:
2154     case ARM::VST1d32Q_UPD:
2155     case ARM::VST1d64Q_UPD:
2156     case ARM::VST2q8:
2157     case ARM::VST2q16:
2158     case ARM::VST2q32:
2159     case ARM::VST2q8_UPD:
2160     case ARM::VST2q16_UPD:
2161     case ARM::VST2q32_UPD:
2162     case ARM::VST3d8:
2163     case ARM::VST3d16:
2164     case ARM::VST3d32:
2165     case ARM::VST3d8_UPD:
2166     case ARM::VST3d16_UPD:
2167     case ARM::VST3d32_UPD:
2168     case ARM::VST4d8:
2169     case ARM::VST4d16:
2170     case ARM::VST4d32:
2171     case ARM::VST4d8_UPD:
2172     case ARM::VST4d16_UPD:
2173     case ARM::VST4d32_UPD:
2174       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2175         return MCDisassembler::Fail;
2176       break;
2177     case ARM::VST3q8:
2178     case ARM::VST3q16:
2179     case ARM::VST3q32:
2180     case ARM::VST3q8_UPD:
2181     case ARM::VST3q16_UPD:
2182     case ARM::VST3q32_UPD:
2183     case ARM::VST4q8:
2184     case ARM::VST4q16:
2185     case ARM::VST4q32:
2186     case ARM::VST4q8_UPD:
2187     case ARM::VST4q16_UPD:
2188     case ARM::VST4q32_UPD:
2189       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2190         return MCDisassembler::Fail;
2191       break;
2192     default:
2193       break;
2194   }
2195 
2196   // Fourth input register
2197   switch (Inst.getOpcode()) {
2198     case ARM::VST1d8Q:
2199     case ARM::VST1d16Q:
2200     case ARM::VST1d32Q:
2201     case ARM::VST1d64Q:
2202     case ARM::VST1d8Q_UPD:
2203     case ARM::VST1d16Q_UPD:
2204     case ARM::VST1d32Q_UPD:
2205     case ARM::VST1d64Q_UPD:
2206     case ARM::VST2q8:
2207     case ARM::VST2q16:
2208     case ARM::VST2q32:
2209     case ARM::VST2q8_UPD:
2210     case ARM::VST2q16_UPD:
2211     case ARM::VST2q32_UPD:
2212     case ARM::VST4d8:
2213     case ARM::VST4d16:
2214     case ARM::VST4d32:
2215     case ARM::VST4d8_UPD:
2216     case ARM::VST4d16_UPD:
2217     case ARM::VST4d32_UPD:
2218       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2219         return MCDisassembler::Fail;
2220       break;
2221     case ARM::VST4q8:
2222     case ARM::VST4q16:
2223     case ARM::VST4q32:
2224     case ARM::VST4q8_UPD:
2225     case ARM::VST4q16_UPD:
2226     case ARM::VST4q32_UPD:
2227       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2228         return MCDisassembler::Fail;
2229       break;
2230     default:
2231       break;
2232   }
2233 
2234   return S;
2235 }
2236 
2237 static DecodeStatus DecodeVLD1DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2238                                     uint64_t Address, const void *Decoder) {
2239   DecodeStatus S = MCDisassembler::Success;
2240 
2241   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2242   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2243   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2244   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2245   unsigned align = fieldFromInstruction32(Insn, 4, 1);
2246   unsigned size = fieldFromInstruction32(Insn, 6, 2);
2247   unsigned regs = fieldFromInstruction32(Insn, 5, 1) + 1;
2248 
2249   align *= (1 << size);
2250 
2251   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2252     return MCDisassembler::Fail;
2253   if (regs == 2) {
2254     if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2255       return MCDisassembler::Fail;
2256   }
2257   if (Rm != 0xF) {
2258     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2259       return MCDisassembler::Fail;
2260   }
2261 
2262   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2263     return MCDisassembler::Fail;
2264   Inst.addOperand(MCOperand::CreateImm(align));
2265 
2266   if (Rm == 0xD)
2267     Inst.addOperand(MCOperand::CreateReg(0));
2268   else if (Rm != 0xF) {
2269     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2270       return MCDisassembler::Fail;
2271   }
2272 
2273   return S;
2274 }
2275 
2276 static DecodeStatus DecodeVLD2DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2277                                     uint64_t Address, const void *Decoder) {
2278   DecodeStatus S = MCDisassembler::Success;
2279 
2280   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2281   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2282   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2283   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2284   unsigned align = fieldFromInstruction32(Insn, 4, 1);
2285   unsigned size = 1 << fieldFromInstruction32(Insn, 6, 2);
2286   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2287   align *= 2*size;
2288 
2289   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2290     return MCDisassembler::Fail;
2291   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
2292     return MCDisassembler::Fail;
2293   if (Rm != 0xF) {
2294     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2295       return MCDisassembler::Fail;
2296   }
2297 
2298   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2299     return MCDisassembler::Fail;
2300   Inst.addOperand(MCOperand::CreateImm(align));
2301 
2302   if (Rm == 0xD)
2303     Inst.addOperand(MCOperand::CreateReg(0));
2304   else if (Rm != 0xF) {
2305     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2306       return MCDisassembler::Fail;
2307   }
2308 
2309   return S;
2310 }
2311 
2312 static DecodeStatus DecodeVLD3DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2313                                     uint64_t Address, const void *Decoder) {
2314   DecodeStatus S = MCDisassembler::Success;
2315 
2316   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2317   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2318   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2319   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2320   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2321 
2322   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2323     return MCDisassembler::Fail;
2324   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
2325     return MCDisassembler::Fail;
2326   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
2327     return MCDisassembler::Fail;
2328   if (Rm != 0xF) {
2329     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2330       return MCDisassembler::Fail;
2331   }
2332 
2333   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2334     return MCDisassembler::Fail;
2335   Inst.addOperand(MCOperand::CreateImm(0));
2336 
2337   if (Rm == 0xD)
2338     Inst.addOperand(MCOperand::CreateReg(0));
2339   else if (Rm != 0xF) {
2340     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2341       return MCDisassembler::Fail;
2342   }
2343 
2344   return S;
2345 }
2346 
2347 static DecodeStatus DecodeVLD4DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2348                                     uint64_t Address, const void *Decoder) {
2349   DecodeStatus S = MCDisassembler::Success;
2350 
2351   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2352   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2353   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2354   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2355   unsigned size = fieldFromInstruction32(Insn, 6, 2);
2356   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2357   unsigned align = fieldFromInstruction32(Insn, 4, 1);
2358 
2359   if (size == 0x3) {
2360     size = 4;
2361     align = 16;
2362   } else {
2363     if (size == 2) {
2364       size = 1 << size;
2365       align *= 8;
2366     } else {
2367       size = 1 << size;
2368       align *= 4*size;
2369     }
2370   }
2371 
2372   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2373     return MCDisassembler::Fail;
2374   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
2375     return MCDisassembler::Fail;
2376   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
2377     return MCDisassembler::Fail;
2378   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
2379     return MCDisassembler::Fail;
2380   if (Rm != 0xF) {
2381     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2382       return MCDisassembler::Fail;
2383   }
2384 
2385   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2386     return MCDisassembler::Fail;
2387   Inst.addOperand(MCOperand::CreateImm(align));
2388 
2389   if (Rm == 0xD)
2390     Inst.addOperand(MCOperand::CreateReg(0));
2391   else if (Rm != 0xF) {
2392     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2393       return MCDisassembler::Fail;
2394   }
2395 
2396   return S;
2397 }
2398 
2399 static DecodeStatus
2400 DecodeNEONModImmInstruction(llvm::MCInst &Inst, unsigned Insn,
2401                             uint64_t Address, const void *Decoder) {
2402   DecodeStatus S = MCDisassembler::Success;
2403 
2404   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2405   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2406   unsigned imm = fieldFromInstruction32(Insn, 0, 4);
2407   imm |= fieldFromInstruction32(Insn, 16, 3) << 4;
2408   imm |= fieldFromInstruction32(Insn, 24, 1) << 7;
2409   imm |= fieldFromInstruction32(Insn, 8, 4) << 8;
2410   imm |= fieldFromInstruction32(Insn, 5, 1) << 12;
2411   unsigned Q = fieldFromInstruction32(Insn, 6, 1);
2412 
2413   if (Q) {
2414     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
2415     return MCDisassembler::Fail;
2416   } else {
2417     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2418     return MCDisassembler::Fail;
2419   }
2420 
2421   Inst.addOperand(MCOperand::CreateImm(imm));
2422 
2423   switch (Inst.getOpcode()) {
2424     case ARM::VORRiv4i16:
2425     case ARM::VORRiv2i32:
2426     case ARM::VBICiv4i16:
2427     case ARM::VBICiv2i32:
2428       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2429         return MCDisassembler::Fail;
2430       break;
2431     case ARM::VORRiv8i16:
2432     case ARM::VORRiv4i32:
2433     case ARM::VBICiv8i16:
2434     case ARM::VBICiv4i32:
2435       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
2436         return MCDisassembler::Fail;
2437       break;
2438     default:
2439       break;
2440   }
2441 
2442   return S;
2443 }
2444 
2445 static DecodeStatus DecodeVSHLMaxInstruction(llvm::MCInst &Inst, unsigned Insn,
2446                                         uint64_t Address, const void *Decoder) {
2447   DecodeStatus S = MCDisassembler::Success;
2448 
2449   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2450   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2451   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2452   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2453   unsigned size = fieldFromInstruction32(Insn, 18, 2);
2454 
2455   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
2456     return MCDisassembler::Fail;
2457   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
2458     return MCDisassembler::Fail;
2459   Inst.addOperand(MCOperand::CreateImm(8 << size));
2460 
2461   return S;
2462 }
2463 
2464 static DecodeStatus DecodeShiftRight8Imm(llvm::MCInst &Inst, unsigned Val,
2465                                uint64_t Address, const void *Decoder) {
2466   Inst.addOperand(MCOperand::CreateImm(8 - Val));
2467   return MCDisassembler::Success;
2468 }
2469 
2470 static DecodeStatus DecodeShiftRight16Imm(llvm::MCInst &Inst, unsigned Val,
2471                                uint64_t Address, const void *Decoder) {
2472   Inst.addOperand(MCOperand::CreateImm(16 - Val));
2473   return MCDisassembler::Success;
2474 }
2475 
2476 static DecodeStatus DecodeShiftRight32Imm(llvm::MCInst &Inst, unsigned Val,
2477                                uint64_t Address, const void *Decoder) {
2478   Inst.addOperand(MCOperand::CreateImm(32 - Val));
2479   return MCDisassembler::Success;
2480 }
2481 
2482 static DecodeStatus DecodeShiftRight64Imm(llvm::MCInst &Inst, unsigned Val,
2483                                uint64_t Address, const void *Decoder) {
2484   Inst.addOperand(MCOperand::CreateImm(64 - Val));
2485   return MCDisassembler::Success;
2486 }
2487 
2488 static DecodeStatus DecodeTBLInstruction(llvm::MCInst &Inst, unsigned Insn,
2489                                uint64_t Address, const void *Decoder) {
2490   DecodeStatus S = MCDisassembler::Success;
2491 
2492   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2493   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2494   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2495   Rn |= fieldFromInstruction32(Insn, 7, 1) << 4;
2496   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2497   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2498   unsigned op = fieldFromInstruction32(Insn, 6, 1);
2499   unsigned length = fieldFromInstruction32(Insn, 8, 2) + 1;
2500 
2501   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2502     return MCDisassembler::Fail;
2503   if (op) {
2504     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2505     return MCDisassembler::Fail; // Writeback
2506   }
2507 
2508   for (unsigned i = 0; i < length; ++i) {
2509     if (!Check(S, DecodeDPRRegisterClass(Inst, (Rn+i)%32, Address, Decoder)))
2510     return MCDisassembler::Fail;
2511   }
2512 
2513   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
2514     return MCDisassembler::Fail;
2515 
2516   return S;
2517 }
2518 
2519 static DecodeStatus DecodeVFPfpImm(llvm::MCInst &Inst, unsigned Val,
2520                             uint64_t Address, const void *Decoder) {
2521   // The immediate needs to be a fully instantiated float.  However, the
2522   // auto-generated decoder is only able to fill in some of the bits
2523   // necessary.  For instance, the 'b' bit is replicated multiple times,
2524   // and is even present in inverted form in one bit.  We do a little
2525   // binary parsing here to fill in those missing bits, and then
2526   // reinterpret it all as a float.
2527   union {
2528     uint32_t integer;
2529     float fp;
2530   } fp_conv;
2531 
2532   fp_conv.integer = Val;
2533   uint32_t b = fieldFromInstruction32(Val, 25, 1);
2534   fp_conv.integer |= b << 26;
2535   fp_conv.integer |= b << 27;
2536   fp_conv.integer |= b << 28;
2537   fp_conv.integer |= b << 29;
2538   fp_conv.integer |= (~b & 0x1) << 30;
2539 
2540   Inst.addOperand(MCOperand::CreateFPImm(fp_conv.fp));
2541   return MCDisassembler::Success;
2542 }
2543 
2544 static DecodeStatus DecodeThumbAddSpecialReg(llvm::MCInst &Inst, uint16_t Insn,
2545                                      uint64_t Address, const void *Decoder) {
2546   DecodeStatus S = MCDisassembler::Success;
2547 
2548   unsigned dst = fieldFromInstruction16(Insn, 8, 3);
2549   unsigned imm = fieldFromInstruction16(Insn, 0, 8);
2550 
2551   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
2552     return MCDisassembler::Fail;
2553 
2554   switch(Inst.getOpcode()) {
2555     default:
2556       return MCDisassembler::Fail;
2557     case ARM::tADR:
2558       break; // tADR does not explicitly represent the PC as an operand.
2559     case ARM::tADDrSPi:
2560       Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2561       break;
2562   }
2563 
2564   Inst.addOperand(MCOperand::CreateImm(imm));
2565   return S;
2566 }
2567 
2568 static DecodeStatus DecodeThumbBROperand(llvm::MCInst &Inst, unsigned Val,
2569                                  uint64_t Address, const void *Decoder) {
2570   Inst.addOperand(MCOperand::CreateImm(SignExtend32<12>(Val << 1)));
2571   return MCDisassembler::Success;
2572 }
2573 
2574 static DecodeStatus DecodeT2BROperand(llvm::MCInst &Inst, unsigned Val,
2575                                  uint64_t Address, const void *Decoder) {
2576   Inst.addOperand(MCOperand::CreateImm(SignExtend32<21>(Val)));
2577   return MCDisassembler::Success;
2578 }
2579 
2580 static DecodeStatus DecodeThumbCmpBROperand(llvm::MCInst &Inst, unsigned Val,
2581                                  uint64_t Address, const void *Decoder) {
2582   Inst.addOperand(MCOperand::CreateImm(SignExtend32<7>(Val << 1)));
2583   return MCDisassembler::Success;
2584 }
2585 
2586 static DecodeStatus DecodeThumbAddrModeRR(llvm::MCInst &Inst, unsigned Val,
2587                                  uint64_t Address, const void *Decoder) {
2588   DecodeStatus S = MCDisassembler::Success;
2589 
2590   unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2591   unsigned Rm = fieldFromInstruction32(Val, 3, 3);
2592 
2593   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
2594     return MCDisassembler::Fail;
2595   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
2596     return MCDisassembler::Fail;
2597 
2598   return S;
2599 }
2600 
2601 static DecodeStatus DecodeThumbAddrModeIS(llvm::MCInst &Inst, unsigned Val,
2602                                   uint64_t Address, const void *Decoder) {
2603   DecodeStatus S = MCDisassembler::Success;
2604 
2605   unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2606   unsigned imm = fieldFromInstruction32(Val, 3, 5);
2607 
2608   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
2609     return MCDisassembler::Fail;
2610   Inst.addOperand(MCOperand::CreateImm(imm));
2611 
2612   return S;
2613 }
2614 
2615 static DecodeStatus DecodeThumbAddrModePC(llvm::MCInst &Inst, unsigned Val,
2616                                   uint64_t Address, const void *Decoder) {
2617   Inst.addOperand(MCOperand::CreateImm(Val << 2));
2618 
2619   return MCDisassembler::Success;
2620 }
2621 
2622 static DecodeStatus DecodeThumbAddrModeSP(llvm::MCInst &Inst, unsigned Val,
2623                                   uint64_t Address, const void *Decoder) {
2624   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2625   Inst.addOperand(MCOperand::CreateImm(Val));
2626 
2627   return MCDisassembler::Success;
2628 }
2629 
2630 static DecodeStatus DecodeT2AddrModeSOReg(llvm::MCInst &Inst, unsigned Val,
2631                                   uint64_t Address, const void *Decoder) {
2632   DecodeStatus S = MCDisassembler::Success;
2633 
2634   unsigned Rn = fieldFromInstruction32(Val, 6, 4);
2635   unsigned Rm = fieldFromInstruction32(Val, 2, 4);
2636   unsigned imm = fieldFromInstruction32(Val, 0, 2);
2637 
2638   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2639     return MCDisassembler::Fail;
2640   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
2641     return MCDisassembler::Fail;
2642   Inst.addOperand(MCOperand::CreateImm(imm));
2643 
2644   return S;
2645 }
2646 
2647 static DecodeStatus DecodeT2LoadShift(llvm::MCInst &Inst, unsigned Insn,
2648                               uint64_t Address, const void *Decoder) {
2649   DecodeStatus S = MCDisassembler::Success;
2650 
2651   switch (Inst.getOpcode()) {
2652     case ARM::t2PLDs:
2653     case ARM::t2PLDWs:
2654     case ARM::t2PLIs:
2655       break;
2656     default: {
2657       unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2658       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2659     return MCDisassembler::Fail;
2660     }
2661   }
2662 
2663   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2664   if (Rn == 0xF) {
2665     switch (Inst.getOpcode()) {
2666       case ARM::t2LDRBs:
2667         Inst.setOpcode(ARM::t2LDRBpci);
2668         break;
2669       case ARM::t2LDRHs:
2670         Inst.setOpcode(ARM::t2LDRHpci);
2671         break;
2672       case ARM::t2LDRSHs:
2673         Inst.setOpcode(ARM::t2LDRSHpci);
2674         break;
2675       case ARM::t2LDRSBs:
2676         Inst.setOpcode(ARM::t2LDRSBpci);
2677         break;
2678       case ARM::t2PLDs:
2679         Inst.setOpcode(ARM::t2PLDi12);
2680         Inst.addOperand(MCOperand::CreateReg(ARM::PC));
2681         break;
2682       default:
2683         return MCDisassembler::Fail;
2684     }
2685 
2686     int imm = fieldFromInstruction32(Insn, 0, 12);
2687     if (!fieldFromInstruction32(Insn, 23, 1)) imm *= -1;
2688     Inst.addOperand(MCOperand::CreateImm(imm));
2689 
2690     return S;
2691   }
2692 
2693   unsigned addrmode = fieldFromInstruction32(Insn, 4, 2);
2694   addrmode |= fieldFromInstruction32(Insn, 0, 4) << 2;
2695   addrmode |= fieldFromInstruction32(Insn, 16, 4) << 6;
2696   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
2697     return MCDisassembler::Fail;
2698 
2699   return S;
2700 }
2701 
2702 static DecodeStatus DecodeT2Imm8S4(llvm::MCInst &Inst, unsigned Val,
2703                            uint64_t Address, const void *Decoder) {
2704   int imm = Val & 0xFF;
2705   if (!(Val & 0x100)) imm *= -1;
2706   Inst.addOperand(MCOperand::CreateImm(imm << 2));
2707 
2708   return MCDisassembler::Success;
2709 }
2710 
2711 static DecodeStatus DecodeT2AddrModeImm8s4(llvm::MCInst &Inst, unsigned Val,
2712                                    uint64_t Address, const void *Decoder) {
2713   DecodeStatus S = MCDisassembler::Success;
2714 
2715   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2716   unsigned imm = fieldFromInstruction32(Val, 0, 9);
2717 
2718   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2719     return MCDisassembler::Fail;
2720   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
2721     return MCDisassembler::Fail;
2722 
2723   return S;
2724 }
2725 
2726 static DecodeStatus DecodeT2AddrModeImm0_1020s4(llvm::MCInst &Inst,unsigned Val,
2727                                    uint64_t Address, const void *Decoder) {
2728   DecodeStatus S = MCDisassembler::Success;
2729 
2730   unsigned Rn = fieldFromInstruction32(Val, 8, 4);
2731   unsigned imm = fieldFromInstruction32(Val, 0, 8);
2732 
2733   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2734     return MCDisassembler::Fail;
2735 
2736   Inst.addOperand(MCOperand::CreateImm(imm));
2737 
2738   return S;
2739 }
2740 
2741 static DecodeStatus DecodeT2Imm8(llvm::MCInst &Inst, unsigned Val,
2742                          uint64_t Address, const void *Decoder) {
2743   int imm = Val & 0xFF;
2744   if (Val == 0)
2745     imm = INT32_MIN;
2746   else if (!(Val & 0x100))
2747     imm *= -1;
2748   Inst.addOperand(MCOperand::CreateImm(imm));
2749 
2750   return MCDisassembler::Success;
2751 }
2752 
2753 
2754 static DecodeStatus DecodeT2AddrModeImm8(llvm::MCInst &Inst, unsigned Val,
2755                                  uint64_t Address, const void *Decoder) {
2756   DecodeStatus S = MCDisassembler::Success;
2757 
2758   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2759   unsigned imm = fieldFromInstruction32(Val, 0, 9);
2760 
2761   // Some instructions always use an additive offset.
2762   switch (Inst.getOpcode()) {
2763     case ARM::t2LDRT:
2764     case ARM::t2LDRBT:
2765     case ARM::t2LDRHT:
2766     case ARM::t2LDRSBT:
2767     case ARM::t2LDRSHT:
2768     case ARM::t2STRT:
2769     case ARM::t2STRBT:
2770     case ARM::t2STRHT:
2771       imm |= 0x100;
2772       break;
2773     default:
2774       break;
2775   }
2776 
2777   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2778     return MCDisassembler::Fail;
2779   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
2780     return MCDisassembler::Fail;
2781 
2782   return S;
2783 }
2784 
2785 static DecodeStatus DecodeT2LdStPre(llvm::MCInst &Inst, unsigned Insn,
2786                                     uint64_t Address, const void *Decoder) {
2787   DecodeStatus S = MCDisassembler::Success;
2788 
2789   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2790   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2791   unsigned addr = fieldFromInstruction32(Insn, 0, 8);
2792   addr |= fieldFromInstruction32(Insn, 9, 1) << 8;
2793   addr |= Rn << 9;
2794   unsigned load = fieldFromInstruction32(Insn, 20, 1);
2795 
2796   if (!load) {
2797     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2798       return MCDisassembler::Fail;
2799   }
2800 
2801   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
2802     return MCDisassembler::Fail;
2803 
2804   if (load) {
2805     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2806       return MCDisassembler::Fail;
2807   }
2808 
2809   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
2810     return MCDisassembler::Fail;
2811 
2812   return S;
2813 }
2814 
2815 static DecodeStatus DecodeT2AddrModeImm12(llvm::MCInst &Inst, unsigned Val,
2816                                   uint64_t Address, const void *Decoder) {
2817   DecodeStatus S = MCDisassembler::Success;
2818 
2819   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
2820   unsigned imm = fieldFromInstruction32(Val, 0, 12);
2821 
2822   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2823     return MCDisassembler::Fail;
2824   Inst.addOperand(MCOperand::CreateImm(imm));
2825 
2826   return S;
2827 }
2828 
2829 
2830 static DecodeStatus DecodeThumbAddSPImm(llvm::MCInst &Inst, uint16_t Insn,
2831                                 uint64_t Address, const void *Decoder) {
2832   unsigned imm = fieldFromInstruction16(Insn, 0, 7);
2833 
2834   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2835   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2836   Inst.addOperand(MCOperand::CreateImm(imm));
2837 
2838   return MCDisassembler::Success;
2839 }
2840 
2841 static DecodeStatus DecodeThumbAddSPReg(llvm::MCInst &Inst, uint16_t Insn,
2842                                 uint64_t Address, const void *Decoder) {
2843   DecodeStatus S = MCDisassembler::Success;
2844 
2845   if (Inst.getOpcode() == ARM::tADDrSP) {
2846     unsigned Rdm = fieldFromInstruction16(Insn, 0, 3);
2847     Rdm |= fieldFromInstruction16(Insn, 7, 1) << 3;
2848 
2849     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
2850     return MCDisassembler::Fail;
2851     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
2852     return MCDisassembler::Fail;
2853     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2854   } else if (Inst.getOpcode() == ARM::tADDspr) {
2855     unsigned Rm = fieldFromInstruction16(Insn, 3, 4);
2856 
2857     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2858     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2859     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2860     return MCDisassembler::Fail;
2861   }
2862 
2863   return S;
2864 }
2865 
2866 static DecodeStatus DecodeThumbCPS(llvm::MCInst &Inst, uint16_t Insn,
2867                            uint64_t Address, const void *Decoder) {
2868   unsigned imod = fieldFromInstruction16(Insn, 4, 1) | 0x2;
2869   unsigned flags = fieldFromInstruction16(Insn, 0, 3);
2870 
2871   Inst.addOperand(MCOperand::CreateImm(imod));
2872   Inst.addOperand(MCOperand::CreateImm(flags));
2873 
2874   return MCDisassembler::Success;
2875 }
2876 
2877 static DecodeStatus DecodePostIdxReg(llvm::MCInst &Inst, unsigned Insn,
2878                              uint64_t Address, const void *Decoder) {
2879   DecodeStatus S = MCDisassembler::Success;
2880   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2881   unsigned add = fieldFromInstruction32(Insn, 4, 1);
2882 
2883   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2884     return MCDisassembler::Fail;
2885   Inst.addOperand(MCOperand::CreateImm(add));
2886 
2887   return S;
2888 }
2889 
2890 static DecodeStatus DecodeThumbBLXOffset(llvm::MCInst &Inst, unsigned Val,
2891                                  uint64_t Address, const void *Decoder) {
2892   Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
2893   return MCDisassembler::Success;
2894 }
2895 
2896 static DecodeStatus DecodeCoprocessor(llvm::MCInst &Inst, unsigned Val,
2897                               uint64_t Address, const void *Decoder) {
2898   if (Val == 0xA || Val == 0xB)
2899     return MCDisassembler::Fail;
2900 
2901   Inst.addOperand(MCOperand::CreateImm(Val));
2902   return MCDisassembler::Success;
2903 }
2904 
2905 static DecodeStatus
2906 DecodeThumbTableBranch(llvm::MCInst &Inst, unsigned Insn,
2907                        uint64_t Address, const void *Decoder) {
2908   DecodeStatus S = MCDisassembler::Success;
2909 
2910   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2911   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2912 
2913   if (Rn == ARM::SP) S = MCDisassembler::SoftFail;
2914   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2915     return MCDisassembler::Fail;
2916   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
2917     return MCDisassembler::Fail;
2918   return S;
2919 }
2920 
2921 static DecodeStatus
2922 DecodeThumb2BCCInstruction(llvm::MCInst &Inst, unsigned Insn,
2923                            uint64_t Address, const void *Decoder) {
2924   DecodeStatus S = MCDisassembler::Success;
2925 
2926   unsigned pred = fieldFromInstruction32(Insn, 22, 4);
2927   if (pred == 0xE || pred == 0xF) {
2928     unsigned opc = fieldFromInstruction32(Insn, 4, 28);
2929     switch (opc) {
2930       default:
2931         return MCDisassembler::Fail;
2932       case 0xf3bf8f4:
2933         Inst.setOpcode(ARM::t2DSB);
2934         break;
2935       case 0xf3bf8f5:
2936         Inst.setOpcode(ARM::t2DMB);
2937         break;
2938       case 0xf3bf8f6:
2939         Inst.setOpcode(ARM::t2ISB);
2940         break;
2941     }
2942 
2943     unsigned imm = fieldFromInstruction32(Insn, 0, 4);
2944     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
2945   }
2946 
2947   unsigned brtarget = fieldFromInstruction32(Insn, 0, 11) << 1;
2948   brtarget |= fieldFromInstruction32(Insn, 11, 1) << 19;
2949   brtarget |= fieldFromInstruction32(Insn, 13, 1) << 18;
2950   brtarget |= fieldFromInstruction32(Insn, 16, 6) << 12;
2951   brtarget |= fieldFromInstruction32(Insn, 26, 1) << 20;
2952 
2953   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
2954     return MCDisassembler::Fail;
2955   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2956     return MCDisassembler::Fail;
2957 
2958   return S;
2959 }
2960 
2961 // Decode a shifted immediate operand.  These basically consist
2962 // of an 8-bit value, and a 4-bit directive that specifies either
2963 // a splat operation or a rotation.
2964 static DecodeStatus DecodeT2SOImm(llvm::MCInst &Inst, unsigned Val,
2965                           uint64_t Address, const void *Decoder) {
2966   unsigned ctrl = fieldFromInstruction32(Val, 10, 2);
2967   if (ctrl == 0) {
2968     unsigned byte = fieldFromInstruction32(Val, 8, 2);
2969     unsigned imm = fieldFromInstruction32(Val, 0, 8);
2970     switch (byte) {
2971       case 0:
2972         Inst.addOperand(MCOperand::CreateImm(imm));
2973         break;
2974       case 1:
2975         Inst.addOperand(MCOperand::CreateImm((imm << 16) | imm));
2976         break;
2977       case 2:
2978         Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 8)));
2979         break;
2980       case 3:
2981         Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 16) |
2982                                              (imm << 8)  |  imm));
2983         break;
2984     }
2985   } else {
2986     unsigned unrot = fieldFromInstruction32(Val, 0, 7) | 0x80;
2987     unsigned rot = fieldFromInstruction32(Val, 7, 5);
2988     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
2989     Inst.addOperand(MCOperand::CreateImm(imm));
2990   }
2991 
2992   return MCDisassembler::Success;
2993 }
2994 
2995 static DecodeStatus
2996 DecodeThumbBCCTargetOperand(llvm::MCInst &Inst, unsigned Val,
2997                             uint64_t Address, const void *Decoder){
2998   Inst.addOperand(MCOperand::CreateImm(Val << 1));
2999   return MCDisassembler::Success;
3000 }
3001 
3002 static DecodeStatus DecodeThumbBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
3003                                        uint64_t Address, const void *Decoder){
3004   Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
3005   return MCDisassembler::Success;
3006 }
3007 
3008 static DecodeStatus DecodeMemBarrierOption(llvm::MCInst &Inst, unsigned Val,
3009                                    uint64_t Address, const void *Decoder) {
3010   switch (Val) {
3011   default:
3012     return MCDisassembler::Fail;
3013   case 0xF: // SY
3014   case 0xE: // ST
3015   case 0xB: // ISH
3016   case 0xA: // ISHST
3017   case 0x7: // NSH
3018   case 0x6: // NSHST
3019   case 0x3: // OSH
3020   case 0x2: // OSHST
3021     break;
3022   }
3023 
3024   Inst.addOperand(MCOperand::CreateImm(Val));
3025   return MCDisassembler::Success;
3026 }
3027 
3028 static DecodeStatus DecodeMSRMask(llvm::MCInst &Inst, unsigned Val,
3029                           uint64_t Address, const void *Decoder) {
3030   if (!Val) return MCDisassembler::Fail;
3031   Inst.addOperand(MCOperand::CreateImm(Val));
3032   return MCDisassembler::Success;
3033 }
3034 
3035 static DecodeStatus DecodeDoubleRegLoad(llvm::MCInst &Inst, unsigned Insn,
3036                                         uint64_t Address, const void *Decoder) {
3037   DecodeStatus S = MCDisassembler::Success;
3038 
3039   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3040   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3041   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3042 
3043   if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return MCDisassembler::Fail;
3044 
3045   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3046     return MCDisassembler::Fail;
3047   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
3048     return MCDisassembler::Fail;
3049   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3050     return MCDisassembler::Fail;
3051   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3052     return MCDisassembler::Fail;
3053 
3054   return S;
3055 }
3056 
3057 
3058 static DecodeStatus DecodeDoubleRegStore(llvm::MCInst &Inst, unsigned Insn,
3059                                          uint64_t Address, const void *Decoder){
3060   DecodeStatus S = MCDisassembler::Success;
3061 
3062   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3063   unsigned Rt = fieldFromInstruction32(Insn, 0, 4);
3064   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3065   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3066 
3067   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
3068     return MCDisassembler::Fail;
3069 
3070   if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return MCDisassembler::Fail;
3071   if (Rd == Rn || Rd == Rt || Rd == Rt+1) return MCDisassembler::Fail;
3072 
3073   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3074     return MCDisassembler::Fail;
3075   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
3076     return MCDisassembler::Fail;
3077   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3078     return MCDisassembler::Fail;
3079   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3080     return MCDisassembler::Fail;
3081 
3082   return S;
3083 }
3084 
3085 static DecodeStatus DecodeLDRPreImm(llvm::MCInst &Inst, unsigned Insn,
3086                             uint64_t Address, const void *Decoder) {
3087   DecodeStatus S = MCDisassembler::Success;
3088 
3089   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3090   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3091   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3092   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3093   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3094   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3095 
3096   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3097 
3098   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3099     return MCDisassembler::Fail;
3100   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3101     return MCDisassembler::Fail;
3102   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
3103     return MCDisassembler::Fail;
3104   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3105     return MCDisassembler::Fail;
3106 
3107   return S;
3108 }
3109 
3110 static DecodeStatus DecodeLDRPreReg(llvm::MCInst &Inst, unsigned Insn,
3111                             uint64_t Address, const void *Decoder) {
3112   DecodeStatus S = MCDisassembler::Success;
3113 
3114   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3115   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3116   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3117   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3118   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3119   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3120   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3121 
3122   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3123   if (Rm == 0xF) S = MCDisassembler::SoftFail;
3124 
3125   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3126     return MCDisassembler::Fail;
3127   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3128     return MCDisassembler::Fail;
3129   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
3130     return MCDisassembler::Fail;
3131   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3132     return MCDisassembler::Fail;
3133 
3134   return S;
3135 }
3136 
3137 
3138 static DecodeStatus DecodeSTRPreImm(llvm::MCInst &Inst, unsigned Insn,
3139                             uint64_t Address, const void *Decoder) {
3140   DecodeStatus S = MCDisassembler::Success;
3141 
3142   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3143   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3144   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3145   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3146   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3147   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3148 
3149   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3150 
3151   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3152     return MCDisassembler::Fail;
3153   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3154     return MCDisassembler::Fail;
3155   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
3156     return MCDisassembler::Fail;
3157   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3158     return MCDisassembler::Fail;
3159 
3160   return S;
3161 }
3162 
3163 static DecodeStatus DecodeSTRPreReg(llvm::MCInst &Inst, unsigned Insn,
3164                             uint64_t Address, const void *Decoder) {
3165   DecodeStatus S = MCDisassembler::Success;
3166 
3167   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3168   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3169   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3170   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3171   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3172   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3173 
3174   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3175 
3176   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3177     return MCDisassembler::Fail;
3178   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3179     return MCDisassembler::Fail;
3180   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
3181     return MCDisassembler::Fail;
3182   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3183     return MCDisassembler::Fail;
3184 
3185   return S;
3186 }
3187 
3188 static DecodeStatus DecodeVLD1LN(llvm::MCInst &Inst, unsigned Insn,
3189                          uint64_t Address, const void *Decoder) {
3190   DecodeStatus S = MCDisassembler::Success;
3191 
3192   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3193   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3194   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3195   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3196   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3197 
3198   unsigned align = 0;
3199   unsigned index = 0;
3200   switch (size) {
3201     default:
3202       return MCDisassembler::Fail;
3203     case 0:
3204       if (fieldFromInstruction32(Insn, 4, 1))
3205         return MCDisassembler::Fail; // UNDEFINED
3206       index = fieldFromInstruction32(Insn, 5, 3);
3207       break;
3208     case 1:
3209       if (fieldFromInstruction32(Insn, 5, 1))
3210         return MCDisassembler::Fail; // UNDEFINED
3211       index = fieldFromInstruction32(Insn, 6, 2);
3212       if (fieldFromInstruction32(Insn, 4, 1))
3213         align = 2;
3214       break;
3215     case 2:
3216       if (fieldFromInstruction32(Insn, 6, 1))
3217         return MCDisassembler::Fail; // UNDEFINED
3218       index = fieldFromInstruction32(Insn, 7, 1);
3219       if (fieldFromInstruction32(Insn, 4, 2) != 0)
3220         align = 4;
3221   }
3222 
3223   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3224     return MCDisassembler::Fail;
3225   if (Rm != 0xF) { // Writeback
3226     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3227       return MCDisassembler::Fail;
3228   }
3229   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3230     return MCDisassembler::Fail;
3231   Inst.addOperand(MCOperand::CreateImm(align));
3232   if (Rm != 0xF) {
3233     if (Rm != 0xD) {
3234       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3235         return MCDisassembler::Fail;
3236     } else
3237       Inst.addOperand(MCOperand::CreateReg(0));
3238   }
3239 
3240   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3241     return MCDisassembler::Fail;
3242   Inst.addOperand(MCOperand::CreateImm(index));
3243 
3244   return S;
3245 }
3246 
3247 static DecodeStatus DecodeVST1LN(llvm::MCInst &Inst, unsigned Insn,
3248                          uint64_t Address, const void *Decoder) {
3249   DecodeStatus S = MCDisassembler::Success;
3250 
3251   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3252   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3253   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3254   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3255   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3256 
3257   unsigned align = 0;
3258   unsigned index = 0;
3259   switch (size) {
3260     default:
3261       return MCDisassembler::Fail;
3262     case 0:
3263       if (fieldFromInstruction32(Insn, 4, 1))
3264         return MCDisassembler::Fail; // UNDEFINED
3265       index = fieldFromInstruction32(Insn, 5, 3);
3266       break;
3267     case 1:
3268       if (fieldFromInstruction32(Insn, 5, 1))
3269         return MCDisassembler::Fail; // UNDEFINED
3270       index = fieldFromInstruction32(Insn, 6, 2);
3271       if (fieldFromInstruction32(Insn, 4, 1))
3272         align = 2;
3273       break;
3274     case 2:
3275       if (fieldFromInstruction32(Insn, 6, 1))
3276         return MCDisassembler::Fail; // UNDEFINED
3277       index = fieldFromInstruction32(Insn, 7, 1);
3278       if (fieldFromInstruction32(Insn, 4, 2) != 0)
3279         align = 4;
3280   }
3281 
3282   if (Rm != 0xF) { // Writeback
3283     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3284     return MCDisassembler::Fail;
3285   }
3286   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3287     return MCDisassembler::Fail;
3288   Inst.addOperand(MCOperand::CreateImm(align));
3289   if (Rm != 0xF) {
3290     if (Rm != 0xD) {
3291       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3292     return MCDisassembler::Fail;
3293     } else
3294       Inst.addOperand(MCOperand::CreateReg(0));
3295   }
3296 
3297   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3298     return MCDisassembler::Fail;
3299   Inst.addOperand(MCOperand::CreateImm(index));
3300 
3301   return S;
3302 }
3303 
3304 
3305 static DecodeStatus DecodeVLD2LN(llvm::MCInst &Inst, unsigned Insn,
3306                          uint64_t Address, const void *Decoder) {
3307   DecodeStatus S = MCDisassembler::Success;
3308 
3309   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3310   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3311   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3312   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3313   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3314 
3315   unsigned align = 0;
3316   unsigned index = 0;
3317   unsigned inc = 1;
3318   switch (size) {
3319     default:
3320       return MCDisassembler::Fail;
3321     case 0:
3322       index = fieldFromInstruction32(Insn, 5, 3);
3323       if (fieldFromInstruction32(Insn, 4, 1))
3324         align = 2;
3325       break;
3326     case 1:
3327       index = fieldFromInstruction32(Insn, 6, 2);
3328       if (fieldFromInstruction32(Insn, 4, 1))
3329         align = 4;
3330       if (fieldFromInstruction32(Insn, 5, 1))
3331         inc = 2;
3332       break;
3333     case 2:
3334       if (fieldFromInstruction32(Insn, 5, 1))
3335         return MCDisassembler::Fail; // UNDEFINED
3336       index = fieldFromInstruction32(Insn, 7, 1);
3337       if (fieldFromInstruction32(Insn, 4, 1) != 0)
3338         align = 8;
3339       if (fieldFromInstruction32(Insn, 6, 1))
3340         inc = 2;
3341       break;
3342   }
3343 
3344   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3345     return MCDisassembler::Fail;
3346   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3347     return MCDisassembler::Fail;
3348   if (Rm != 0xF) { // Writeback
3349     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3350       return MCDisassembler::Fail;
3351   }
3352   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3353     return MCDisassembler::Fail;
3354   Inst.addOperand(MCOperand::CreateImm(align));
3355   if (Rm != 0xF) {
3356     if (Rm != 0xD) {
3357       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3358         return MCDisassembler::Fail;
3359     } else
3360       Inst.addOperand(MCOperand::CreateReg(0));
3361   }
3362 
3363   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3364     return MCDisassembler::Fail;
3365   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3366     return MCDisassembler::Fail;
3367   Inst.addOperand(MCOperand::CreateImm(index));
3368 
3369   return S;
3370 }
3371 
3372 static DecodeStatus DecodeVST2LN(llvm::MCInst &Inst, unsigned Insn,
3373                          uint64_t Address, const void *Decoder) {
3374   DecodeStatus S = MCDisassembler::Success;
3375 
3376   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3377   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3378   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3379   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3380   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3381 
3382   unsigned align = 0;
3383   unsigned index = 0;
3384   unsigned inc = 1;
3385   switch (size) {
3386     default:
3387       return MCDisassembler::Fail;
3388     case 0:
3389       index = fieldFromInstruction32(Insn, 5, 3);
3390       if (fieldFromInstruction32(Insn, 4, 1))
3391         align = 2;
3392       break;
3393     case 1:
3394       index = fieldFromInstruction32(Insn, 6, 2);
3395       if (fieldFromInstruction32(Insn, 4, 1))
3396         align = 4;
3397       if (fieldFromInstruction32(Insn, 5, 1))
3398         inc = 2;
3399       break;
3400     case 2:
3401       if (fieldFromInstruction32(Insn, 5, 1))
3402         return MCDisassembler::Fail; // UNDEFINED
3403       index = fieldFromInstruction32(Insn, 7, 1);
3404       if (fieldFromInstruction32(Insn, 4, 1) != 0)
3405         align = 8;
3406       if (fieldFromInstruction32(Insn, 6, 1))
3407         inc = 2;
3408       break;
3409   }
3410 
3411   if (Rm != 0xF) { // Writeback
3412     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3413       return MCDisassembler::Fail;
3414   }
3415   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3416     return MCDisassembler::Fail;
3417   Inst.addOperand(MCOperand::CreateImm(align));
3418   if (Rm != 0xF) {
3419     if (Rm != 0xD) {
3420       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3421         return MCDisassembler::Fail;
3422     } else
3423       Inst.addOperand(MCOperand::CreateReg(0));
3424   }
3425 
3426   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3427     return MCDisassembler::Fail;
3428   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3429     return MCDisassembler::Fail;
3430   Inst.addOperand(MCOperand::CreateImm(index));
3431 
3432   return S;
3433 }
3434 
3435 
3436 static DecodeStatus DecodeVLD3LN(llvm::MCInst &Inst, unsigned Insn,
3437                          uint64_t Address, const void *Decoder) {
3438   DecodeStatus S = MCDisassembler::Success;
3439 
3440   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3441   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3442   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3443   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3444   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3445 
3446   unsigned align = 0;
3447   unsigned index = 0;
3448   unsigned inc = 1;
3449   switch (size) {
3450     default:
3451       return MCDisassembler::Fail;
3452     case 0:
3453       if (fieldFromInstruction32(Insn, 4, 1))
3454         return MCDisassembler::Fail; // UNDEFINED
3455       index = fieldFromInstruction32(Insn, 5, 3);
3456       break;
3457     case 1:
3458       if (fieldFromInstruction32(Insn, 4, 1))
3459         return MCDisassembler::Fail; // UNDEFINED
3460       index = fieldFromInstruction32(Insn, 6, 2);
3461       if (fieldFromInstruction32(Insn, 5, 1))
3462         inc = 2;
3463       break;
3464     case 2:
3465       if (fieldFromInstruction32(Insn, 4, 2))
3466         return MCDisassembler::Fail; // UNDEFINED
3467       index = fieldFromInstruction32(Insn, 7, 1);
3468       if (fieldFromInstruction32(Insn, 6, 1))
3469         inc = 2;
3470       break;
3471   }
3472 
3473   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3474     return MCDisassembler::Fail;
3475   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3476     return MCDisassembler::Fail;
3477   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3478     return MCDisassembler::Fail;
3479 
3480   if (Rm != 0xF) { // Writeback
3481     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3482     return MCDisassembler::Fail;
3483   }
3484   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3485     return MCDisassembler::Fail;
3486   Inst.addOperand(MCOperand::CreateImm(align));
3487   if (Rm != 0xF) {
3488     if (Rm != 0xD) {
3489       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3490     return MCDisassembler::Fail;
3491     } else
3492       Inst.addOperand(MCOperand::CreateReg(0));
3493   }
3494 
3495   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3496     return MCDisassembler::Fail;
3497   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3498     return MCDisassembler::Fail;
3499   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3500     return MCDisassembler::Fail;
3501   Inst.addOperand(MCOperand::CreateImm(index));
3502 
3503   return S;
3504 }
3505 
3506 static DecodeStatus DecodeVST3LN(llvm::MCInst &Inst, unsigned Insn,
3507                          uint64_t Address, const void *Decoder) {
3508   DecodeStatus S = MCDisassembler::Success;
3509 
3510   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3511   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3512   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3513   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3514   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3515 
3516   unsigned align = 0;
3517   unsigned index = 0;
3518   unsigned inc = 1;
3519   switch (size) {
3520     default:
3521       return MCDisassembler::Fail;
3522     case 0:
3523       if (fieldFromInstruction32(Insn, 4, 1))
3524         return MCDisassembler::Fail; // UNDEFINED
3525       index = fieldFromInstruction32(Insn, 5, 3);
3526       break;
3527     case 1:
3528       if (fieldFromInstruction32(Insn, 4, 1))
3529         return MCDisassembler::Fail; // UNDEFINED
3530       index = fieldFromInstruction32(Insn, 6, 2);
3531       if (fieldFromInstruction32(Insn, 5, 1))
3532         inc = 2;
3533       break;
3534     case 2:
3535       if (fieldFromInstruction32(Insn, 4, 2))
3536         return MCDisassembler::Fail; // UNDEFINED
3537       index = fieldFromInstruction32(Insn, 7, 1);
3538       if (fieldFromInstruction32(Insn, 6, 1))
3539         inc = 2;
3540       break;
3541   }
3542 
3543   if (Rm != 0xF) { // Writeback
3544     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3545     return MCDisassembler::Fail;
3546   }
3547   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3548     return MCDisassembler::Fail;
3549   Inst.addOperand(MCOperand::CreateImm(align));
3550   if (Rm != 0xF) {
3551     if (Rm != 0xD) {
3552       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3553     return MCDisassembler::Fail;
3554     } else
3555       Inst.addOperand(MCOperand::CreateReg(0));
3556   }
3557 
3558   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3559     return MCDisassembler::Fail;
3560   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3561     return MCDisassembler::Fail;
3562   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3563     return MCDisassembler::Fail;
3564   Inst.addOperand(MCOperand::CreateImm(index));
3565 
3566   return S;
3567 }
3568 
3569 
3570 static DecodeStatus DecodeVLD4LN(llvm::MCInst &Inst, unsigned Insn,
3571                          uint64_t Address, const void *Decoder) {
3572   DecodeStatus S = MCDisassembler::Success;
3573 
3574   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3575   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3576   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3577   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3578   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3579 
3580   unsigned align = 0;
3581   unsigned index = 0;
3582   unsigned inc = 1;
3583   switch (size) {
3584     default:
3585       return MCDisassembler::Fail;
3586     case 0:
3587       if (fieldFromInstruction32(Insn, 4, 1))
3588         align = 4;
3589       index = fieldFromInstruction32(Insn, 5, 3);
3590       break;
3591     case 1:
3592       if (fieldFromInstruction32(Insn, 4, 1))
3593         align = 8;
3594       index = fieldFromInstruction32(Insn, 6, 2);
3595       if (fieldFromInstruction32(Insn, 5, 1))
3596         inc = 2;
3597       break;
3598     case 2:
3599       if (fieldFromInstruction32(Insn, 4, 2))
3600         align = 4 << fieldFromInstruction32(Insn, 4, 2);
3601       index = fieldFromInstruction32(Insn, 7, 1);
3602       if (fieldFromInstruction32(Insn, 6, 1))
3603         inc = 2;
3604       break;
3605   }
3606 
3607   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3608     return MCDisassembler::Fail;
3609   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3610     return MCDisassembler::Fail;
3611   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3612     return MCDisassembler::Fail;
3613   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
3614     return MCDisassembler::Fail;
3615 
3616   if (Rm != 0xF) { // Writeback
3617     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3618       return MCDisassembler::Fail;
3619   }
3620   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3621     return MCDisassembler::Fail;
3622   Inst.addOperand(MCOperand::CreateImm(align));
3623   if (Rm != 0xF) {
3624     if (Rm != 0xD) {
3625       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3626         return MCDisassembler::Fail;
3627     } else
3628       Inst.addOperand(MCOperand::CreateReg(0));
3629   }
3630 
3631   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3632     return MCDisassembler::Fail;
3633   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3634     return MCDisassembler::Fail;
3635   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3636     return MCDisassembler::Fail;
3637   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
3638     return MCDisassembler::Fail;
3639   Inst.addOperand(MCOperand::CreateImm(index));
3640 
3641   return S;
3642 }
3643 
3644 static DecodeStatus DecodeVST4LN(llvm::MCInst &Inst, unsigned Insn,
3645                          uint64_t Address, const void *Decoder) {
3646   DecodeStatus S = MCDisassembler::Success;
3647 
3648   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3649   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3650   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3651   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3652   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3653 
3654   unsigned align = 0;
3655   unsigned index = 0;
3656   unsigned inc = 1;
3657   switch (size) {
3658     default:
3659       return MCDisassembler::Fail;
3660     case 0:
3661       if (fieldFromInstruction32(Insn, 4, 1))
3662         align = 4;
3663       index = fieldFromInstruction32(Insn, 5, 3);
3664       break;
3665     case 1:
3666       if (fieldFromInstruction32(Insn, 4, 1))
3667         align = 8;
3668       index = fieldFromInstruction32(Insn, 6, 2);
3669       if (fieldFromInstruction32(Insn, 5, 1))
3670         inc = 2;
3671       break;
3672     case 2:
3673       if (fieldFromInstruction32(Insn, 4, 2))
3674         align = 4 << fieldFromInstruction32(Insn, 4, 2);
3675       index = fieldFromInstruction32(Insn, 7, 1);
3676       if (fieldFromInstruction32(Insn, 6, 1))
3677         inc = 2;
3678       break;
3679   }
3680 
3681   if (Rm != 0xF) { // Writeback
3682     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3683     return MCDisassembler::Fail;
3684   }
3685   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3686     return MCDisassembler::Fail;
3687   Inst.addOperand(MCOperand::CreateImm(align));
3688   if (Rm != 0xF) {
3689     if (Rm != 0xD) {
3690       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3691     return MCDisassembler::Fail;
3692     } else
3693       Inst.addOperand(MCOperand::CreateReg(0));
3694   }
3695 
3696   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3697     return MCDisassembler::Fail;
3698   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3699     return MCDisassembler::Fail;
3700   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3701     return MCDisassembler::Fail;
3702   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
3703     return MCDisassembler::Fail;
3704   Inst.addOperand(MCOperand::CreateImm(index));
3705 
3706   return S;
3707 }
3708 
3709 static DecodeStatus DecodeVMOVSRR(llvm::MCInst &Inst, unsigned Insn,
3710                                   uint64_t Address, const void *Decoder) {
3711   DecodeStatus S = MCDisassembler::Success;
3712   unsigned Rt  = fieldFromInstruction32(Insn, 12, 4);
3713   unsigned Rt2 = fieldFromInstruction32(Insn, 16, 4);
3714   unsigned Rm  = fieldFromInstruction32(Insn,  0, 4);
3715   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3716   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
3717 
3718   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
3719     S = MCDisassembler::SoftFail;
3720 
3721   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
3722     return MCDisassembler::Fail;
3723   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
3724     return MCDisassembler::Fail;
3725   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
3726     return MCDisassembler::Fail;
3727   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
3728     return MCDisassembler::Fail;
3729   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3730     return MCDisassembler::Fail;
3731 
3732   return S;
3733 }
3734 
3735 static DecodeStatus DecodeVMOVRRS(llvm::MCInst &Inst, unsigned Insn,
3736                                   uint64_t Address, const void *Decoder) {
3737   DecodeStatus S = MCDisassembler::Success;
3738   unsigned Rt  = fieldFromInstruction32(Insn, 12, 4);
3739   unsigned Rt2 = fieldFromInstruction32(Insn, 16, 4);
3740   unsigned Rm  = fieldFromInstruction32(Insn,  0, 4);
3741   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3742   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
3743 
3744   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
3745     S = MCDisassembler::SoftFail;
3746 
3747   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
3748     return MCDisassembler::Fail;
3749   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
3750     return MCDisassembler::Fail;
3751   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
3752     return MCDisassembler::Fail;
3753   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
3754     return MCDisassembler::Fail;
3755   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3756     return MCDisassembler::Fail;
3757 
3758   return S;
3759 }
3760 
3761 static DecodeStatus DecodeIT(llvm::MCInst &Inst, unsigned Insn,
3762                              uint64_t Address, const void *Decoder) {
3763   DecodeStatus S = MCDisassembler::Success;
3764   unsigned pred = fieldFromInstruction16(Insn, 4, 4);
3765   // The InstPrinter needs to have the low bit of the predicate in
3766   // the mask operand to be able to print it properly.
3767   unsigned mask = fieldFromInstruction16(Insn, 0, 5);
3768 
3769   if (pred == 0xF) {
3770     pred = 0xE;
3771     S = MCDisassembler::SoftFail;
3772   }
3773 
3774   if ((mask & 0xF) == 0) {
3775     // Preserve the high bit of the mask, which is the low bit of
3776     // the predicate.
3777     mask &= 0x10;
3778     mask |= 0x8;
3779     S = MCDisassembler::SoftFail;
3780   }
3781 
3782   Inst.addOperand(MCOperand::CreateImm(pred));
3783   Inst.addOperand(MCOperand::CreateImm(mask));
3784   return S;
3785 }
3786 
3787 static DecodeStatus
3788 DecodeT2LDRDPreInstruction(llvm::MCInst &Inst, unsigned Insn,
3789                            uint64_t Address, const void *Decoder) {
3790   DecodeStatus S = MCDisassembler::Success;
3791 
3792   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3793   unsigned Rt2 = fieldFromInstruction32(Insn, 8, 4);
3794   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3795   unsigned addr = fieldFromInstruction32(Insn, 0, 8);
3796   unsigned W = fieldFromInstruction32(Insn, 21, 1);
3797   unsigned U = fieldFromInstruction32(Insn, 23, 1);
3798   unsigned P = fieldFromInstruction32(Insn, 24, 1);
3799   bool writeback = (W == 1) | (P == 0);
3800 
3801   addr |= (U << 8) | (Rn << 9);
3802 
3803   if (writeback && (Rn == Rt || Rn == Rt2))
3804     Check(S, MCDisassembler::SoftFail);
3805   if (Rt == Rt2)
3806     Check(S, MCDisassembler::SoftFail);
3807 
3808   // Rt
3809   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
3810     return MCDisassembler::Fail;
3811   // Rt2
3812   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
3813     return MCDisassembler::Fail;
3814   // Writeback operand
3815   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
3816     return MCDisassembler::Fail;
3817   // addr
3818   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
3819     return MCDisassembler::Fail;
3820 
3821   return S;
3822 }
3823 
3824 static DecodeStatus
3825 DecodeT2STRDPreInstruction(llvm::MCInst &Inst, unsigned Insn,
3826                            uint64_t Address, const void *Decoder) {
3827   DecodeStatus S = MCDisassembler::Success;
3828 
3829   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3830   unsigned Rt2 = fieldFromInstruction32(Insn, 8, 4);
3831   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3832   unsigned addr = fieldFromInstruction32(Insn, 0, 8);
3833   unsigned W = fieldFromInstruction32(Insn, 21, 1);
3834   unsigned U = fieldFromInstruction32(Insn, 23, 1);
3835   unsigned P = fieldFromInstruction32(Insn, 24, 1);
3836   bool writeback = (W == 1) | (P == 0);
3837 
3838   addr |= (U << 8) | (Rn << 9);
3839 
3840   if (writeback && (Rn == Rt || Rn == Rt2))
3841     Check(S, MCDisassembler::SoftFail);
3842 
3843   // Writeback operand
3844   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
3845     return MCDisassembler::Fail;
3846   // Rt
3847   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
3848     return MCDisassembler::Fail;
3849   // Rt2
3850   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
3851     return MCDisassembler::Fail;
3852   // addr
3853   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
3854     return MCDisassembler::Fail;
3855 
3856   return S;
3857 }
3858 
3859 static DecodeStatus DecodeT2Adr(llvm::MCInst &Inst, uint32_t Insn,
3860                                 uint64_t Address, const void *Decoder) {
3861   unsigned sign1 = fieldFromInstruction32(Insn, 21, 1);
3862   unsigned sign2 = fieldFromInstruction32(Insn, 23, 1);
3863   if (sign1 != sign2) return MCDisassembler::Fail;
3864 
3865   unsigned Val = fieldFromInstruction32(Insn, 0, 8);
3866   Val |= fieldFromInstruction32(Insn, 12, 3) << 8;
3867   Val |= fieldFromInstruction32(Insn, 26, 1) << 11;
3868   Val |= sign1 << 12;
3869   Inst.addOperand(MCOperand::CreateImm(SignExtend32<13>(Val)));
3870 
3871   return MCDisassembler::Success;
3872 }
3873 
3874