xref: /llvm-project/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (revision 3ca958cd19cb9bddfbfc7f9d5ee27c0ad07a2ea5)
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 DecodeThumb2BCCInstruction(llvm::MCInst &Inst, unsigned Val,
291                                 uint64_t Address, const void *Decoder);
292 static DecodeStatus DecodeT2SOImm(llvm::MCInst &Inst, unsigned Val,
293                                 uint64_t Address, const void *Decoder);
294 static DecodeStatus DecodeThumbBCCTargetOperand(llvm::MCInst &Inst,unsigned Val,
295                                 uint64_t Address, const void *Decoder);
296 static DecodeStatus DecodeThumbBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
297                                 uint64_t Address, const void *Decoder);
298 static DecodeStatus DecodeIT(llvm::MCInst &Inst, unsigned Val,
299                                 uint64_t Address, const void *Decoder);
300 static DecodeStatus DecodeT2LDRDPreInstruction(llvm::MCInst &Inst,unsigned Insn,
301                                uint64_t Address, const void *Decoder);
302 static DecodeStatus DecodeT2STRDPreInstruction(llvm::MCInst &Inst,unsigned Insn,
303                                uint64_t Address, const void *Decoder);
304 static DecodeStatus DecodeT2Adr(llvm::MCInst &Inst, unsigned Val,
305                                 uint64_t Address, const void *Decoder);
306 static DecodeStatus DecodeT2LdStPre(llvm::MCInst &Inst, unsigned Val,
307                                 uint64_t Address, const void *Decoder);
308 
309 
310 #include "ARMGenDisassemblerTables.inc"
311 #include "ARMGenInstrInfo.inc"
312 #include "ARMGenEDInfo.inc"
313 
314 static MCDisassembler *createARMDisassembler(const Target &T, const MCSubtargetInfo &STI) {
315   return new ARMDisassembler(STI);
316 }
317 
318 static MCDisassembler *createThumbDisassembler(const Target &T, const MCSubtargetInfo &STI) {
319   return new ThumbDisassembler(STI);
320 }
321 
322 EDInstInfo *ARMDisassembler::getEDInfo() const {
323   return instInfoARM;
324 }
325 
326 EDInstInfo *ThumbDisassembler::getEDInfo() const {
327   return instInfoARM;
328 }
329 
330 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
331                                              const MemoryObject &Region,
332                                              uint64_t Address,
333                                              raw_ostream &os,
334                                              raw_ostream &cs) const {
335   uint8_t bytes[4];
336 
337   assert(!(STI.getFeatureBits() & ARM::ModeThumb) &&
338          "Asked to disassemble an ARM instruction but Subtarget is in Thumb mode!");
339 
340   // We want to read exactly 4 bytes of data.
341   if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1) {
342     Size = 0;
343     return MCDisassembler::Fail;
344   }
345 
346   // Encoded as a small-endian 32-bit word in the stream.
347   uint32_t insn = (bytes[3] << 24) |
348                   (bytes[2] << 16) |
349                   (bytes[1] <<  8) |
350                   (bytes[0] <<  0);
351 
352   // Calling the auto-generated decoder function.
353   DecodeStatus result = decodeARMInstruction32(MI, insn, Address, this, STI);
354   if (result != MCDisassembler::Fail) {
355     Size = 4;
356     return result;
357   }
358 
359   // VFP and NEON instructions, similarly, are shared between ARM
360   // and Thumb modes.
361   MI.clear();
362   result = decodeVFPInstruction32(MI, insn, Address, this, STI);
363   if (result != MCDisassembler::Fail) {
364     Size = 4;
365     return result;
366   }
367 
368   MI.clear();
369   result = decodeNEONDataInstruction32(MI, insn, Address, this, STI);
370   if (result != MCDisassembler::Fail) {
371     Size = 4;
372     // Add a fake predicate operand, because we share these instruction
373     // definitions with Thumb2 where these instructions are predicable.
374     if (!DecodePredicateOperand(MI, 0xE, Address, this))
375       return MCDisassembler::Fail;
376     return result;
377   }
378 
379   MI.clear();
380   result = decodeNEONLoadStoreInstruction32(MI, insn, Address, this, STI);
381   if (result != MCDisassembler::Fail) {
382     Size = 4;
383     // Add a fake predicate operand, because we share these instruction
384     // definitions with Thumb2 where these instructions are predicable.
385     if (!DecodePredicateOperand(MI, 0xE, Address, this))
386       return MCDisassembler::Fail;
387     return result;
388   }
389 
390   MI.clear();
391   result = decodeNEONDupInstruction32(MI, insn, Address, this, STI);
392   if (result != MCDisassembler::Fail) {
393     Size = 4;
394     // Add a fake predicate operand, because we share these instruction
395     // definitions with Thumb2 where these instructions are predicable.
396     if (!DecodePredicateOperand(MI, 0xE, Address, this))
397       return MCDisassembler::Fail;
398     return result;
399   }
400 
401   MI.clear();
402 
403   Size = 0;
404   return MCDisassembler::Fail;
405 }
406 
407 namespace llvm {
408 extern MCInstrDesc ARMInsts[];
409 }
410 
411 // Thumb1 instructions don't have explicit S bits.  Rather, they
412 // implicitly set CPSR.  Since it's not represented in the encoding, the
413 // auto-generated decoder won't inject the CPSR operand.  We need to fix
414 // that as a post-pass.
415 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
416   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
417   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
418   MCInst::iterator I = MI.begin();
419   for (unsigned i = 0; i < NumOps; ++i, ++I) {
420     if (I == MI.end()) break;
421     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
422       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
423       MI.insert(I, MCOperand::CreateReg(InITBlock ? 0 : ARM::CPSR));
424       return;
425     }
426   }
427 
428   MI.insert(I, MCOperand::CreateReg(InITBlock ? 0 : ARM::CPSR));
429 }
430 
431 // Most Thumb instructions don't have explicit predicates in the
432 // encoding, but rather get their predicates from IT context.  We need
433 // to fix up the predicate operands using this context information as a
434 // post-pass.
435 MCDisassembler::DecodeStatus
436 ThumbDisassembler::AddThumbPredicate(MCInst &MI) const {
437   MCDisassembler::DecodeStatus S = Success;
438 
439   // A few instructions actually have predicates encoded in them.  Don't
440   // try to overwrite it if we're seeing one of those.
441   switch (MI.getOpcode()) {
442     case ARM::tBcc:
443     case ARM::t2Bcc:
444     case ARM::tCBZ:
445     case ARM::tCBNZ:
446       // Some instructions (mostly conditional branches) are not
447       // allowed in IT blocks.
448       if (!ITBlock.empty())
449         S = SoftFail;
450       else
451         return Success;
452       break;
453     case ARM::tB:
454     case ARM::t2B:
455       // Some instructions (mostly unconditional branches) can
456       // only appears at the end of, or outside of, an IT.
457       if (ITBlock.size() > 1)
458         S = SoftFail;
459       break;
460     default:
461       break;
462   }
463 
464   // If we're in an IT block, base the predicate on that.  Otherwise,
465   // assume a predicate of AL.
466   unsigned CC;
467   if (!ITBlock.empty()) {
468     CC = ITBlock.back();
469     if (CC == 0xF)
470       CC = ARMCC::AL;
471     ITBlock.pop_back();
472   } else
473     CC = ARMCC::AL;
474 
475   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
476   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
477   MCInst::iterator I = MI.begin();
478   for (unsigned i = 0; i < NumOps; ++i, ++I) {
479     if (I == MI.end()) break;
480     if (OpInfo[i].isPredicate()) {
481       I = MI.insert(I, MCOperand::CreateImm(CC));
482       ++I;
483       if (CC == ARMCC::AL)
484         MI.insert(I, MCOperand::CreateReg(0));
485       else
486         MI.insert(I, MCOperand::CreateReg(ARM::CPSR));
487       return S;
488     }
489   }
490 
491   I = MI.insert(I, MCOperand::CreateImm(CC));
492   ++I;
493   if (CC == ARMCC::AL)
494     MI.insert(I, MCOperand::CreateReg(0));
495   else
496     MI.insert(I, MCOperand::CreateReg(ARM::CPSR));
497 
498   return S;
499 }
500 
501 // Thumb VFP instructions are a special case.  Because we share their
502 // encodings between ARM and Thumb modes, and they are predicable in ARM
503 // mode, the auto-generated decoder will give them an (incorrect)
504 // predicate operand.  We need to rewrite these operands based on the IT
505 // context as a post-pass.
506 void ThumbDisassembler::UpdateThumbVFPPredicate(MCInst &MI) const {
507   unsigned CC;
508   if (!ITBlock.empty()) {
509     CC = ITBlock.back();
510     ITBlock.pop_back();
511   } else
512     CC = ARMCC::AL;
513 
514   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
515   MCInst::iterator I = MI.begin();
516   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
517   for (unsigned i = 0; i < NumOps; ++i, ++I) {
518     if (OpInfo[i].isPredicate() ) {
519       I->setImm(CC);
520       ++I;
521       if (CC == ARMCC::AL)
522         I->setReg(0);
523       else
524         I->setReg(ARM::CPSR);
525       return;
526     }
527   }
528 }
529 
530 DecodeStatus ThumbDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
531                                                const MemoryObject &Region,
532                                                uint64_t Address,
533                                                raw_ostream &os,
534                                                raw_ostream &cs) const {
535   uint8_t bytes[4];
536 
537   assert((STI.getFeatureBits() & ARM::ModeThumb) &&
538          "Asked to disassemble in Thumb mode but Subtarget is in ARM mode!");
539 
540   // We want to read exactly 2 bytes of data.
541   if (Region.readBytes(Address, 2, (uint8_t*)bytes, NULL) == -1) {
542     Size = 0;
543     return MCDisassembler::Fail;
544   }
545 
546   uint16_t insn16 = (bytes[1] << 8) | bytes[0];
547   DecodeStatus result = decodeThumbInstruction16(MI, insn16, Address, this, STI);
548   if (result != MCDisassembler::Fail) {
549     Size = 2;
550     Check(result, AddThumbPredicate(MI));
551     return result;
552   }
553 
554   MI.clear();
555   result = decodeThumbSBitInstruction16(MI, insn16, Address, this, STI);
556   if (result) {
557     Size = 2;
558     bool InITBlock = !ITBlock.empty();
559     Check(result, AddThumbPredicate(MI));
560     AddThumb1SBit(MI, InITBlock);
561     return result;
562   }
563 
564   MI.clear();
565   result = decodeThumb2Instruction16(MI, insn16, Address, this, STI);
566   if (result != MCDisassembler::Fail) {
567     Size = 2;
568     Check(result, AddThumbPredicate(MI));
569 
570     // If we find an IT instruction, we need to parse its condition
571     // code and mask operands so that we can apply them correctly
572     // to the subsequent instructions.
573     if (MI.getOpcode() == ARM::t2IT) {
574       // Nested IT blocks are UNPREDICTABLE.
575       if (!ITBlock.empty())
576         return MCDisassembler::SoftFail;
577 
578       // (3 - the number of trailing zeros) is the number of then / else.
579       unsigned firstcond = MI.getOperand(0).getImm();
580       unsigned Mask = MI.getOperand(1).getImm();
581       unsigned CondBit0 = Mask >> 4 & 1;
582       unsigned NumTZ = CountTrailingZeros_32(Mask);
583       assert(NumTZ <= 3 && "Invalid IT mask!");
584       for (unsigned Pos = 3, e = NumTZ; Pos > e; --Pos) {
585         bool T = ((Mask >> Pos) & 1) == CondBit0;
586         if (T)
587           ITBlock.insert(ITBlock.begin(), firstcond);
588         else
589           ITBlock.insert(ITBlock.begin(), firstcond ^ 1);
590       }
591 
592       ITBlock.push_back(firstcond);
593     }
594 
595     return result;
596   }
597 
598   // We want to read exactly 4 bytes of data.
599   if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1) {
600     Size = 0;
601     return MCDisassembler::Fail;
602   }
603 
604   uint32_t insn32 = (bytes[3] <<  8) |
605                     (bytes[2] <<  0) |
606                     (bytes[1] << 24) |
607                     (bytes[0] << 16);
608   MI.clear();
609   result = decodeThumbInstruction32(MI, insn32, Address, this, STI);
610   if (result != MCDisassembler::Fail) {
611     Size = 4;
612     bool InITBlock = ITBlock.size();
613     Check(result, AddThumbPredicate(MI));
614     AddThumb1SBit(MI, InITBlock);
615     return result;
616   }
617 
618   MI.clear();
619   result = decodeThumb2Instruction32(MI, insn32, Address, this, STI);
620   if (result != MCDisassembler::Fail) {
621     Size = 4;
622     Check(result, AddThumbPredicate(MI));
623     return result;
624   }
625 
626   MI.clear();
627   result = decodeVFPInstruction32(MI, insn32, Address, this, STI);
628   if (result != MCDisassembler::Fail) {
629     Size = 4;
630     UpdateThumbVFPPredicate(MI);
631     return result;
632   }
633 
634   MI.clear();
635   result = decodeNEONDupInstruction32(MI, insn32, Address, this, STI);
636   if (result != MCDisassembler::Fail) {
637     Size = 4;
638     Check(result, AddThumbPredicate(MI));
639     return result;
640   }
641 
642   if (fieldFromInstruction32(insn32, 24, 8) == 0xF9) {
643     MI.clear();
644     uint32_t NEONLdStInsn = insn32;
645     NEONLdStInsn &= 0xF0FFFFFF;
646     NEONLdStInsn |= 0x04000000;
647     result = decodeNEONLoadStoreInstruction32(MI, NEONLdStInsn, Address, this, STI);
648     if (result != MCDisassembler::Fail) {
649       Size = 4;
650       Check(result, AddThumbPredicate(MI));
651       return result;
652     }
653   }
654 
655   if (fieldFromInstruction32(insn32, 24, 4) == 0xF) {
656     MI.clear();
657     uint32_t NEONDataInsn = insn32;
658     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
659     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
660     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
661     result = decodeNEONDataInstruction32(MI, NEONDataInsn, Address, this, STI);
662     if (result != MCDisassembler::Fail) {
663       Size = 4;
664       Check(result, AddThumbPredicate(MI));
665       return result;
666     }
667   }
668 
669   Size = 0;
670   return MCDisassembler::Fail;
671 }
672 
673 
674 extern "C" void LLVMInitializeARMDisassembler() {
675   TargetRegistry::RegisterMCDisassembler(TheARMTarget,
676                                          createARMDisassembler);
677   TargetRegistry::RegisterMCDisassembler(TheThumbTarget,
678                                          createThumbDisassembler);
679 }
680 
681 static const unsigned GPRDecoderTable[] = {
682   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
683   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
684   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
685   ARM::R12, ARM::SP, ARM::LR, ARM::PC
686 };
687 
688 static DecodeStatus DecodeGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
689                                    uint64_t Address, const void *Decoder) {
690   if (RegNo > 15)
691     return MCDisassembler::Fail;
692 
693   unsigned Register = GPRDecoderTable[RegNo];
694   Inst.addOperand(MCOperand::CreateReg(Register));
695   return MCDisassembler::Success;
696 }
697 
698 static DecodeStatus
699 DecodeGPRnopcRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
700                            uint64_t Address, const void *Decoder) {
701   if (RegNo == 15) return MCDisassembler::Fail;
702   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
703 }
704 
705 static DecodeStatus DecodetGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
706                                    uint64_t Address, const void *Decoder) {
707   if (RegNo > 7)
708     return MCDisassembler::Fail;
709   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
710 }
711 
712 static DecodeStatus DecodetcGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
713                                    uint64_t Address, const void *Decoder) {
714   unsigned Register = 0;
715   switch (RegNo) {
716     case 0:
717       Register = ARM::R0;
718       break;
719     case 1:
720       Register = ARM::R1;
721       break;
722     case 2:
723       Register = ARM::R2;
724       break;
725     case 3:
726       Register = ARM::R3;
727       break;
728     case 9:
729       Register = ARM::R9;
730       break;
731     case 12:
732       Register = ARM::R12;
733       break;
734     default:
735       return MCDisassembler::Fail;
736     }
737 
738   Inst.addOperand(MCOperand::CreateReg(Register));
739   return MCDisassembler::Success;
740 }
741 
742 static DecodeStatus DecoderGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
743                                    uint64_t Address, const void *Decoder) {
744   if (RegNo == 13 || RegNo == 15) return MCDisassembler::Fail;
745   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
746 }
747 
748 static const unsigned SPRDecoderTable[] = {
749      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
750      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
751      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
752     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
753     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
754     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
755     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
756     ARM::S28, ARM::S29, ARM::S30, ARM::S31
757 };
758 
759 static DecodeStatus DecodeSPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
760                                    uint64_t Address, const void *Decoder) {
761   if (RegNo > 31)
762     return MCDisassembler::Fail;
763 
764   unsigned Register = SPRDecoderTable[RegNo];
765   Inst.addOperand(MCOperand::CreateReg(Register));
766   return MCDisassembler::Success;
767 }
768 
769 static const unsigned DPRDecoderTable[] = {
770      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
771      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
772      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
773     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
774     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
775     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
776     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
777     ARM::D28, ARM::D29, ARM::D30, ARM::D31
778 };
779 
780 static DecodeStatus DecodeDPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
781                                    uint64_t Address, const void *Decoder) {
782   if (RegNo > 31)
783     return MCDisassembler::Fail;
784 
785   unsigned Register = DPRDecoderTable[RegNo];
786   Inst.addOperand(MCOperand::CreateReg(Register));
787   return MCDisassembler::Success;
788 }
789 
790 static DecodeStatus DecodeDPR_8RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
791                                    uint64_t Address, const void *Decoder) {
792   if (RegNo > 7)
793     return MCDisassembler::Fail;
794   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
795 }
796 
797 static DecodeStatus
798 DecodeDPR_VFP2RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
799                             uint64_t Address, const void *Decoder) {
800   if (RegNo > 15)
801     return MCDisassembler::Fail;
802   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
803 }
804 
805 static const unsigned QPRDecoderTable[] = {
806      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
807      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
808      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
809     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
810 };
811 
812 
813 static DecodeStatus DecodeQPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
814                                    uint64_t Address, const void *Decoder) {
815   if (RegNo > 31)
816     return MCDisassembler::Fail;
817   RegNo >>= 1;
818 
819   unsigned Register = QPRDecoderTable[RegNo];
820   Inst.addOperand(MCOperand::CreateReg(Register));
821   return MCDisassembler::Success;
822 }
823 
824 static DecodeStatus DecodePredicateOperand(llvm::MCInst &Inst, unsigned Val,
825                                uint64_t Address, const void *Decoder) {
826   if (Val == 0xF) return MCDisassembler::Fail;
827   // AL predicate is not allowed on Thumb1 branches.
828   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
829     return MCDisassembler::Fail;
830   Inst.addOperand(MCOperand::CreateImm(Val));
831   if (Val == ARMCC::AL) {
832     Inst.addOperand(MCOperand::CreateReg(0));
833   } else
834     Inst.addOperand(MCOperand::CreateReg(ARM::CPSR));
835   return MCDisassembler::Success;
836 }
837 
838 static DecodeStatus DecodeCCOutOperand(llvm::MCInst &Inst, unsigned Val,
839                                uint64_t Address, const void *Decoder) {
840   if (Val)
841     Inst.addOperand(MCOperand::CreateReg(ARM::CPSR));
842   else
843     Inst.addOperand(MCOperand::CreateReg(0));
844   return MCDisassembler::Success;
845 }
846 
847 static DecodeStatus DecodeSOImmOperand(llvm::MCInst &Inst, unsigned Val,
848                                uint64_t Address, const void *Decoder) {
849   uint32_t imm = Val & 0xFF;
850   uint32_t rot = (Val & 0xF00) >> 7;
851   uint32_t rot_imm = (imm >> rot) | (imm << (32-rot));
852   Inst.addOperand(MCOperand::CreateImm(rot_imm));
853   return MCDisassembler::Success;
854 }
855 
856 static DecodeStatus DecodeSORegImmOperand(llvm::MCInst &Inst, unsigned Val,
857                                uint64_t Address, const void *Decoder) {
858   DecodeStatus S = MCDisassembler::Success;
859 
860   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
861   unsigned type = fieldFromInstruction32(Val, 5, 2);
862   unsigned imm = fieldFromInstruction32(Val, 7, 5);
863 
864   // Register-immediate
865   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
866     return MCDisassembler::Fail;
867 
868   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
869   switch (type) {
870     case 0:
871       Shift = ARM_AM::lsl;
872       break;
873     case 1:
874       Shift = ARM_AM::lsr;
875       break;
876     case 2:
877       Shift = ARM_AM::asr;
878       break;
879     case 3:
880       Shift = ARM_AM::ror;
881       break;
882   }
883 
884   if (Shift == ARM_AM::ror && imm == 0)
885     Shift = ARM_AM::rrx;
886 
887   unsigned Op = Shift | (imm << 3);
888   Inst.addOperand(MCOperand::CreateImm(Op));
889 
890   return S;
891 }
892 
893 static DecodeStatus DecodeSORegRegOperand(llvm::MCInst &Inst, unsigned Val,
894                                uint64_t Address, const void *Decoder) {
895   DecodeStatus S = MCDisassembler::Success;
896 
897   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
898   unsigned type = fieldFromInstruction32(Val, 5, 2);
899   unsigned Rs = fieldFromInstruction32(Val, 8, 4);
900 
901   // Register-register
902   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
903     return MCDisassembler::Fail;
904   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)))
905     return MCDisassembler::Fail;
906 
907   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
908   switch (type) {
909     case 0:
910       Shift = ARM_AM::lsl;
911       break;
912     case 1:
913       Shift = ARM_AM::lsr;
914       break;
915     case 2:
916       Shift = ARM_AM::asr;
917       break;
918     case 3:
919       Shift = ARM_AM::ror;
920       break;
921   }
922 
923   Inst.addOperand(MCOperand::CreateImm(Shift));
924 
925   return S;
926 }
927 
928 static DecodeStatus DecodeRegListOperand(llvm::MCInst &Inst, unsigned Val,
929                                  uint64_t Address, const void *Decoder) {
930   DecodeStatus S = MCDisassembler::Success;
931 
932   bool writebackLoad = false;
933   unsigned writebackReg = 0;
934   switch (Inst.getOpcode()) {
935     default:
936       break;
937     case ARM::LDMIA_UPD:
938     case ARM::LDMDB_UPD:
939     case ARM::LDMIB_UPD:
940     case ARM::LDMDA_UPD:
941     case ARM::t2LDMIA_UPD:
942     case ARM::t2LDMDB_UPD:
943       writebackLoad = true;
944       writebackReg = Inst.getOperand(0).getReg();
945       break;
946   }
947 
948   // Empty register lists are not allowed.
949   if (CountPopulation_32(Val) == 0) return MCDisassembler::Fail;
950   for (unsigned i = 0; i < 16; ++i) {
951     if (Val & (1 << i)) {
952       if (!Check(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder)))
953         return MCDisassembler::Fail;
954       // Writeback not allowed if Rn is in the target list.
955       if (writebackLoad && writebackReg == Inst.end()[-1].getReg())
956         Check(S, MCDisassembler::SoftFail);
957     }
958   }
959 
960   return S;
961 }
962 
963 static DecodeStatus DecodeSPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
964                                  uint64_t Address, const void *Decoder) {
965   DecodeStatus S = MCDisassembler::Success;
966 
967   unsigned Vd = fieldFromInstruction32(Val, 8, 4);
968   unsigned regs = Val & 0xFF;
969 
970   if (!Check(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)))
971     return MCDisassembler::Fail;
972   for (unsigned i = 0; i < (regs - 1); ++i) {
973     if (!Check(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)))
974       return MCDisassembler::Fail;
975   }
976 
977   return S;
978 }
979 
980 static DecodeStatus DecodeDPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
981                                  uint64_t Address, const void *Decoder) {
982   DecodeStatus S = MCDisassembler::Success;
983 
984   unsigned Vd = fieldFromInstruction32(Val, 8, 4);
985   unsigned regs = (Val & 0xFF) / 2;
986 
987   if (!Check(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)))
988       return MCDisassembler::Fail;
989   for (unsigned i = 0; i < (regs - 1); ++i) {
990     if (!Check(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)))
991       return MCDisassembler::Fail;
992   }
993 
994   return S;
995 }
996 
997 static DecodeStatus DecodeBitfieldMaskOperand(llvm::MCInst &Inst, unsigned Val,
998                                       uint64_t Address, const void *Decoder) {
999   // This operand encodes a mask of contiguous zeros between a specified MSB
1000   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
1001   // the mask of all bits LSB-and-lower, and then xor them to create
1002   // the mask of that's all ones on [msb, lsb].  Finally we not it to
1003   // create the final mask.
1004   unsigned msb = fieldFromInstruction32(Val, 5, 5);
1005   unsigned lsb = fieldFromInstruction32(Val, 0, 5);
1006 
1007   uint32_t msb_mask = (1 << (msb+1)) - 1;
1008   if (msb == 31) msb_mask = 0xFFFFFFFF;
1009   uint32_t lsb_mask = (1 << lsb) - 1;
1010   if (lsb == 31) lsb_mask = 0xFFFFFFFF;
1011 
1012   Inst.addOperand(MCOperand::CreateImm(~(msb_mask ^ lsb_mask)));
1013   return MCDisassembler::Success;
1014 }
1015 
1016 static DecodeStatus DecodeCopMemInstruction(llvm::MCInst &Inst, unsigned Insn,
1017                                   uint64_t Address, const void *Decoder) {
1018   DecodeStatus S = MCDisassembler::Success;
1019 
1020   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1021   unsigned CRd = fieldFromInstruction32(Insn, 12, 4);
1022   unsigned coproc = fieldFromInstruction32(Insn, 8, 4);
1023   unsigned imm = fieldFromInstruction32(Insn, 0, 8);
1024   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1025   unsigned U = fieldFromInstruction32(Insn, 23, 1);
1026 
1027   switch (Inst.getOpcode()) {
1028     case ARM::LDC_OFFSET:
1029     case ARM::LDC_PRE:
1030     case ARM::LDC_POST:
1031     case ARM::LDC_OPTION:
1032     case ARM::LDCL_OFFSET:
1033     case ARM::LDCL_PRE:
1034     case ARM::LDCL_POST:
1035     case ARM::LDCL_OPTION:
1036     case ARM::STC_OFFSET:
1037     case ARM::STC_PRE:
1038     case ARM::STC_POST:
1039     case ARM::STC_OPTION:
1040     case ARM::STCL_OFFSET:
1041     case ARM::STCL_PRE:
1042     case ARM::STCL_POST:
1043     case ARM::STCL_OPTION:
1044     case ARM::t2LDC_OFFSET:
1045     case ARM::t2LDC_PRE:
1046     case ARM::t2LDC_POST:
1047     case ARM::t2LDC_OPTION:
1048     case ARM::t2LDCL_OFFSET:
1049     case ARM::t2LDCL_PRE:
1050     case ARM::t2LDCL_POST:
1051     case ARM::t2LDCL_OPTION:
1052     case ARM::t2STC_OFFSET:
1053     case ARM::t2STC_PRE:
1054     case ARM::t2STC_POST:
1055     case ARM::t2STC_OPTION:
1056     case ARM::t2STCL_OFFSET:
1057     case ARM::t2STCL_PRE:
1058     case ARM::t2STCL_POST:
1059     case ARM::t2STCL_OPTION:
1060       if (coproc == 0xA || coproc == 0xB)
1061         return MCDisassembler::Fail;
1062       break;
1063     default:
1064       break;
1065   }
1066 
1067   Inst.addOperand(MCOperand::CreateImm(coproc));
1068   Inst.addOperand(MCOperand::CreateImm(CRd));
1069   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1070     return MCDisassembler::Fail;
1071   switch (Inst.getOpcode()) {
1072     case ARM::LDC_OPTION:
1073     case ARM::LDCL_OPTION:
1074     case ARM::LDC2_OPTION:
1075     case ARM::LDC2L_OPTION:
1076     case ARM::STC_OPTION:
1077     case ARM::STCL_OPTION:
1078     case ARM::STC2_OPTION:
1079     case ARM::STC2L_OPTION:
1080     case ARM::LDCL_POST:
1081     case ARM::STCL_POST:
1082     case ARM::LDC2L_POST:
1083     case ARM::STC2L_POST:
1084     case ARM::t2LDC_OPTION:
1085     case ARM::t2LDCL_OPTION:
1086     case ARM::t2STC_OPTION:
1087     case ARM::t2STCL_OPTION:
1088     case ARM::t2LDCL_POST:
1089     case ARM::t2STCL_POST:
1090       break;
1091     default:
1092       Inst.addOperand(MCOperand::CreateReg(0));
1093       break;
1094   }
1095 
1096   unsigned P = fieldFromInstruction32(Insn, 24, 1);
1097   unsigned W = fieldFromInstruction32(Insn, 21, 1);
1098 
1099   bool writeback = (P == 0) || (W == 1);
1100   unsigned idx_mode = 0;
1101   if (P && writeback)
1102     idx_mode = ARMII::IndexModePre;
1103   else if (!P && writeback)
1104     idx_mode = ARMII::IndexModePost;
1105 
1106   switch (Inst.getOpcode()) {
1107     case ARM::LDCL_POST:
1108     case ARM::STCL_POST:
1109     case ARM::t2LDCL_POST:
1110     case ARM::t2STCL_POST:
1111     case ARM::LDC2L_POST:
1112     case ARM::STC2L_POST:
1113       imm |= U << 8;
1114     case ARM::LDC_OPTION:
1115     case ARM::LDCL_OPTION:
1116     case ARM::LDC2_OPTION:
1117     case ARM::LDC2L_OPTION:
1118     case ARM::STC_OPTION:
1119     case ARM::STCL_OPTION:
1120     case ARM::STC2_OPTION:
1121     case ARM::STC2L_OPTION:
1122     case ARM::t2LDC_OPTION:
1123     case ARM::t2LDCL_OPTION:
1124     case ARM::t2STC_OPTION:
1125     case ARM::t2STCL_OPTION:
1126       Inst.addOperand(MCOperand::CreateImm(imm));
1127       break;
1128     default:
1129       if (U)
1130         Inst.addOperand(MCOperand::CreateImm(
1131             ARM_AM::getAM2Opc(ARM_AM::add, imm, ARM_AM::lsl, idx_mode)));
1132       else
1133         Inst.addOperand(MCOperand::CreateImm(
1134             ARM_AM::getAM2Opc(ARM_AM::sub, imm, ARM_AM::lsl, idx_mode)));
1135       break;
1136   }
1137 
1138   switch (Inst.getOpcode()) {
1139     case ARM::LDC_OFFSET:
1140     case ARM::LDC_PRE:
1141     case ARM::LDC_POST:
1142     case ARM::LDC_OPTION:
1143     case ARM::LDCL_OFFSET:
1144     case ARM::LDCL_PRE:
1145     case ARM::LDCL_POST:
1146     case ARM::LDCL_OPTION:
1147     case ARM::STC_OFFSET:
1148     case ARM::STC_PRE:
1149     case ARM::STC_POST:
1150     case ARM::STC_OPTION:
1151     case ARM::STCL_OFFSET:
1152     case ARM::STCL_PRE:
1153     case ARM::STCL_POST:
1154     case ARM::STCL_OPTION:
1155       if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1156         return MCDisassembler::Fail;
1157       break;
1158     default:
1159       break;
1160   }
1161 
1162   return S;
1163 }
1164 
1165 static DecodeStatus
1166 DecodeAddrMode2IdxInstruction(llvm::MCInst &Inst, unsigned Insn,
1167                               uint64_t Address, const void *Decoder) {
1168   DecodeStatus S = MCDisassembler::Success;
1169 
1170   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1171   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
1172   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1173   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
1174   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1175   unsigned reg = fieldFromInstruction32(Insn, 25, 1);
1176   unsigned P = fieldFromInstruction32(Insn, 24, 1);
1177   unsigned W = fieldFromInstruction32(Insn, 21, 1);
1178 
1179   // On stores, the writeback operand precedes Rt.
1180   switch (Inst.getOpcode()) {
1181     case ARM::STR_POST_IMM:
1182     case ARM::STR_POST_REG:
1183     case ARM::STRB_POST_IMM:
1184     case ARM::STRB_POST_REG:
1185     case ARM::STRT_POST_REG:
1186     case ARM::STRT_POST_IMM:
1187     case ARM::STRBT_POST_REG:
1188     case ARM::STRBT_POST_IMM:
1189       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1190         return MCDisassembler::Fail;
1191       break;
1192     default:
1193       break;
1194   }
1195 
1196   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1197     return MCDisassembler::Fail;
1198 
1199   // On loads, the writeback operand comes after Rt.
1200   switch (Inst.getOpcode()) {
1201     case ARM::LDR_POST_IMM:
1202     case ARM::LDR_POST_REG:
1203     case ARM::LDRB_POST_IMM:
1204     case ARM::LDRB_POST_REG:
1205     case ARM::LDRBT_POST_REG:
1206     case ARM::LDRBT_POST_IMM:
1207     case ARM::LDRT_POST_REG:
1208     case ARM::LDRT_POST_IMM:
1209       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1210         return MCDisassembler::Fail;
1211       break;
1212     default:
1213       break;
1214   }
1215 
1216   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1217     return MCDisassembler::Fail;
1218 
1219   ARM_AM::AddrOpc Op = ARM_AM::add;
1220   if (!fieldFromInstruction32(Insn, 23, 1))
1221     Op = ARM_AM::sub;
1222 
1223   bool writeback = (P == 0) || (W == 1);
1224   unsigned idx_mode = 0;
1225   if (P && writeback)
1226     idx_mode = ARMII::IndexModePre;
1227   else if (!P && writeback)
1228     idx_mode = ARMII::IndexModePost;
1229 
1230   if (writeback && (Rn == 15 || Rn == Rt))
1231     S = MCDisassembler::SoftFail; // UNPREDICTABLE
1232 
1233   if (reg) {
1234     if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1235       return MCDisassembler::Fail;
1236     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1237     switch( fieldFromInstruction32(Insn, 5, 2)) {
1238       case 0:
1239         Opc = ARM_AM::lsl;
1240         break;
1241       case 1:
1242         Opc = ARM_AM::lsr;
1243         break;
1244       case 2:
1245         Opc = ARM_AM::asr;
1246         break;
1247       case 3:
1248         Opc = ARM_AM::ror;
1249         break;
1250       default:
1251         return MCDisassembler::Fail;
1252     }
1253     unsigned amt = fieldFromInstruction32(Insn, 7, 5);
1254     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1255 
1256     Inst.addOperand(MCOperand::CreateImm(imm));
1257   } else {
1258     Inst.addOperand(MCOperand::CreateReg(0));
1259     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1260     Inst.addOperand(MCOperand::CreateImm(tmp));
1261   }
1262 
1263   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1264     return MCDisassembler::Fail;
1265 
1266   return S;
1267 }
1268 
1269 static DecodeStatus DecodeSORegMemOperand(llvm::MCInst &Inst, unsigned Val,
1270                                   uint64_t Address, const void *Decoder) {
1271   DecodeStatus S = MCDisassembler::Success;
1272 
1273   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
1274   unsigned Rm = fieldFromInstruction32(Val,  0, 4);
1275   unsigned type = fieldFromInstruction32(Val, 5, 2);
1276   unsigned imm = fieldFromInstruction32(Val, 7, 5);
1277   unsigned U = fieldFromInstruction32(Val, 12, 1);
1278 
1279   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1280   switch (type) {
1281     case 0:
1282       ShOp = ARM_AM::lsl;
1283       break;
1284     case 1:
1285       ShOp = ARM_AM::lsr;
1286       break;
1287     case 2:
1288       ShOp = ARM_AM::asr;
1289       break;
1290     case 3:
1291       ShOp = ARM_AM::ror;
1292       break;
1293   }
1294 
1295   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1296     return MCDisassembler::Fail;
1297   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1298     return MCDisassembler::Fail;
1299   unsigned shift;
1300   if (U)
1301     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1302   else
1303     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1304   Inst.addOperand(MCOperand::CreateImm(shift));
1305 
1306   return S;
1307 }
1308 
1309 static DecodeStatus
1310 DecodeAddrMode3Instruction(llvm::MCInst &Inst, unsigned Insn,
1311                            uint64_t Address, const void *Decoder) {
1312   DecodeStatus S = MCDisassembler::Success;
1313 
1314   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
1315   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1316   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1317   unsigned type = fieldFromInstruction32(Insn, 22, 1);
1318   unsigned imm = fieldFromInstruction32(Insn, 8, 4);
1319   unsigned U = ((~fieldFromInstruction32(Insn, 23, 1)) & 1) << 8;
1320   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1321   unsigned W = fieldFromInstruction32(Insn, 21, 1);
1322   unsigned P = fieldFromInstruction32(Insn, 24, 1);
1323 
1324   bool writeback = (W == 1) | (P == 0);
1325 
1326   // For {LD,ST}RD, Rt must be even, else undefined.
1327   switch (Inst.getOpcode()) {
1328     case ARM::STRD:
1329     case ARM::STRD_PRE:
1330     case ARM::STRD_POST:
1331     case ARM::LDRD:
1332     case ARM::LDRD_PRE:
1333     case ARM::LDRD_POST:
1334       if (Rt & 0x1) return MCDisassembler::Fail;
1335       break;
1336     default:
1337       break;
1338   }
1339 
1340   if (writeback) { // Writeback
1341     if (P)
1342       U |= ARMII::IndexModePre << 9;
1343     else
1344       U |= ARMII::IndexModePost << 9;
1345 
1346     // On stores, the writeback operand precedes Rt.
1347     switch (Inst.getOpcode()) {
1348     case ARM::STRD:
1349     case ARM::STRD_PRE:
1350     case ARM::STRD_POST:
1351     case ARM::STRH:
1352     case ARM::STRH_PRE:
1353     case ARM::STRH_POST:
1354       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1355         return MCDisassembler::Fail;
1356       break;
1357     default:
1358       break;
1359     }
1360   }
1361 
1362   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
1363     return MCDisassembler::Fail;
1364   switch (Inst.getOpcode()) {
1365     case ARM::STRD:
1366     case ARM::STRD_PRE:
1367     case ARM::STRD_POST:
1368     case ARM::LDRD:
1369     case ARM::LDRD_PRE:
1370     case ARM::LDRD_POST:
1371       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
1372         return MCDisassembler::Fail;
1373       break;
1374     default:
1375       break;
1376   }
1377 
1378   if (writeback) {
1379     // On loads, the writeback operand comes after Rt.
1380     switch (Inst.getOpcode()) {
1381     case ARM::LDRD:
1382     case ARM::LDRD_PRE:
1383     case ARM::LDRD_POST:
1384     case ARM::LDRH:
1385     case ARM::LDRH_PRE:
1386     case ARM::LDRH_POST:
1387     case ARM::LDRSH:
1388     case ARM::LDRSH_PRE:
1389     case ARM::LDRSH_POST:
1390     case ARM::LDRSB:
1391     case ARM::LDRSB_PRE:
1392     case ARM::LDRSB_POST:
1393     case ARM::LDRHTr:
1394     case ARM::LDRSBTr:
1395       if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1396         return MCDisassembler::Fail;
1397       break;
1398     default:
1399       break;
1400     }
1401   }
1402 
1403   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1404     return MCDisassembler::Fail;
1405 
1406   if (type) {
1407     Inst.addOperand(MCOperand::CreateReg(0));
1408     Inst.addOperand(MCOperand::CreateImm(U | (imm << 4) | Rm));
1409   } else {
1410     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1411     return MCDisassembler::Fail;
1412     Inst.addOperand(MCOperand::CreateImm(U));
1413   }
1414 
1415   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1416     return MCDisassembler::Fail;
1417 
1418   return S;
1419 }
1420 
1421 static DecodeStatus DecodeRFEInstruction(llvm::MCInst &Inst, unsigned Insn,
1422                                  uint64_t Address, const void *Decoder) {
1423   DecodeStatus S = MCDisassembler::Success;
1424 
1425   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1426   unsigned mode = fieldFromInstruction32(Insn, 23, 2);
1427 
1428   switch (mode) {
1429     case 0:
1430       mode = ARM_AM::da;
1431       break;
1432     case 1:
1433       mode = ARM_AM::ia;
1434       break;
1435     case 2:
1436       mode = ARM_AM::db;
1437       break;
1438     case 3:
1439       mode = ARM_AM::ib;
1440       break;
1441   }
1442 
1443   Inst.addOperand(MCOperand::CreateImm(mode));
1444   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1445     return MCDisassembler::Fail;
1446 
1447   return S;
1448 }
1449 
1450 static DecodeStatus DecodeMemMultipleWritebackInstruction(llvm::MCInst &Inst,
1451                                   unsigned Insn,
1452                                   uint64_t Address, const void *Decoder) {
1453   DecodeStatus S = MCDisassembler::Success;
1454 
1455   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1456   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1457   unsigned reglist = fieldFromInstruction32(Insn, 0, 16);
1458 
1459   if (pred == 0xF) {
1460     switch (Inst.getOpcode()) {
1461       case ARM::LDMDA:
1462         Inst.setOpcode(ARM::RFEDA);
1463         break;
1464       case ARM::LDMDA_UPD:
1465         Inst.setOpcode(ARM::RFEDA_UPD);
1466         break;
1467       case ARM::LDMDB:
1468         Inst.setOpcode(ARM::RFEDB);
1469         break;
1470       case ARM::LDMDB_UPD:
1471         Inst.setOpcode(ARM::RFEDB_UPD);
1472         break;
1473       case ARM::LDMIA:
1474         Inst.setOpcode(ARM::RFEIA);
1475         break;
1476       case ARM::LDMIA_UPD:
1477         Inst.setOpcode(ARM::RFEIA_UPD);
1478         break;
1479       case ARM::LDMIB:
1480         Inst.setOpcode(ARM::RFEIB);
1481         break;
1482       case ARM::LDMIB_UPD:
1483         Inst.setOpcode(ARM::RFEIB_UPD);
1484         break;
1485       case ARM::STMDA:
1486         Inst.setOpcode(ARM::SRSDA);
1487         break;
1488       case ARM::STMDA_UPD:
1489         Inst.setOpcode(ARM::SRSDA_UPD);
1490         break;
1491       case ARM::STMDB:
1492         Inst.setOpcode(ARM::SRSDB);
1493         break;
1494       case ARM::STMDB_UPD:
1495         Inst.setOpcode(ARM::SRSDB_UPD);
1496         break;
1497       case ARM::STMIA:
1498         Inst.setOpcode(ARM::SRSIA);
1499         break;
1500       case ARM::STMIA_UPD:
1501         Inst.setOpcode(ARM::SRSIA_UPD);
1502         break;
1503       case ARM::STMIB:
1504         Inst.setOpcode(ARM::SRSIB);
1505         break;
1506       case ARM::STMIB_UPD:
1507         Inst.setOpcode(ARM::SRSIB_UPD);
1508         break;
1509       default:
1510         if (!Check(S, MCDisassembler::Fail)) return MCDisassembler::Fail;
1511     }
1512 
1513     // For stores (which become SRS's, the only operand is the mode.
1514     if (fieldFromInstruction32(Insn, 20, 1) == 0) {
1515       Inst.addOperand(
1516           MCOperand::CreateImm(fieldFromInstruction32(Insn, 0, 4)));
1517       return S;
1518     }
1519 
1520     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
1521   }
1522 
1523   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1524     return MCDisassembler::Fail;
1525   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1526     return MCDisassembler::Fail; // Tied
1527   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1528     return MCDisassembler::Fail;
1529   if (!Check(S, DecodeRegListOperand(Inst, reglist, Address, Decoder)))
1530     return MCDisassembler::Fail;
1531 
1532   return S;
1533 }
1534 
1535 static DecodeStatus DecodeCPSInstruction(llvm::MCInst &Inst, unsigned Insn,
1536                                  uint64_t Address, const void *Decoder) {
1537   unsigned imod = fieldFromInstruction32(Insn, 18, 2);
1538   unsigned M = fieldFromInstruction32(Insn, 17, 1);
1539   unsigned iflags = fieldFromInstruction32(Insn, 6, 3);
1540   unsigned mode = fieldFromInstruction32(Insn, 0, 5);
1541 
1542   DecodeStatus S = MCDisassembler::Success;
1543 
1544   // imod == '01' --> UNPREDICTABLE
1545   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
1546   // return failure here.  The '01' imod value is unprintable, so there's
1547   // nothing useful we could do even if we returned UNPREDICTABLE.
1548 
1549   if (imod == 1) return MCDisassembler::Fail;
1550 
1551   if (imod && M) {
1552     Inst.setOpcode(ARM::CPS3p);
1553     Inst.addOperand(MCOperand::CreateImm(imod));
1554     Inst.addOperand(MCOperand::CreateImm(iflags));
1555     Inst.addOperand(MCOperand::CreateImm(mode));
1556   } else if (imod && !M) {
1557     Inst.setOpcode(ARM::CPS2p);
1558     Inst.addOperand(MCOperand::CreateImm(imod));
1559     Inst.addOperand(MCOperand::CreateImm(iflags));
1560     if (mode) S = MCDisassembler::SoftFail;
1561   } else if (!imod && M) {
1562     Inst.setOpcode(ARM::CPS1p);
1563     Inst.addOperand(MCOperand::CreateImm(mode));
1564     if (iflags) S = MCDisassembler::SoftFail;
1565   } else {
1566     // imod == '00' && M == '0' --> UNPREDICTABLE
1567     Inst.setOpcode(ARM::CPS1p);
1568     Inst.addOperand(MCOperand::CreateImm(mode));
1569     S = MCDisassembler::SoftFail;
1570   }
1571 
1572   return S;
1573 }
1574 
1575 static DecodeStatus DecodeT2CPSInstruction(llvm::MCInst &Inst, unsigned Insn,
1576                                  uint64_t Address, const void *Decoder) {
1577   unsigned imod = fieldFromInstruction32(Insn, 9, 2);
1578   unsigned M = fieldFromInstruction32(Insn, 8, 1);
1579   unsigned iflags = fieldFromInstruction32(Insn, 5, 3);
1580   unsigned mode = fieldFromInstruction32(Insn, 0, 5);
1581 
1582   DecodeStatus S = MCDisassembler::Success;
1583 
1584   // imod == '01' --> UNPREDICTABLE
1585   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
1586   // return failure here.  The '01' imod value is unprintable, so there's
1587   // nothing useful we could do even if we returned UNPREDICTABLE.
1588 
1589   if (imod == 1) return MCDisassembler::Fail;
1590 
1591   if (imod && M) {
1592     Inst.setOpcode(ARM::t2CPS3p);
1593     Inst.addOperand(MCOperand::CreateImm(imod));
1594     Inst.addOperand(MCOperand::CreateImm(iflags));
1595     Inst.addOperand(MCOperand::CreateImm(mode));
1596   } else if (imod && !M) {
1597     Inst.setOpcode(ARM::t2CPS2p);
1598     Inst.addOperand(MCOperand::CreateImm(imod));
1599     Inst.addOperand(MCOperand::CreateImm(iflags));
1600     if (mode) S = MCDisassembler::SoftFail;
1601   } else if (!imod && M) {
1602     Inst.setOpcode(ARM::t2CPS1p);
1603     Inst.addOperand(MCOperand::CreateImm(mode));
1604     if (iflags) S = MCDisassembler::SoftFail;
1605   } else {
1606     // imod == '00' && M == '0' --> UNPREDICTABLE
1607     Inst.setOpcode(ARM::t2CPS1p);
1608     Inst.addOperand(MCOperand::CreateImm(mode));
1609     S = MCDisassembler::SoftFail;
1610   }
1611 
1612   return S;
1613 }
1614 
1615 
1616 static DecodeStatus DecodeSMLAInstruction(llvm::MCInst &Inst, unsigned Insn,
1617                                  uint64_t Address, const void *Decoder) {
1618   DecodeStatus S = MCDisassembler::Success;
1619 
1620   unsigned Rd = fieldFromInstruction32(Insn, 16, 4);
1621   unsigned Rn = fieldFromInstruction32(Insn, 0, 4);
1622   unsigned Rm = fieldFromInstruction32(Insn, 8, 4);
1623   unsigned Ra = fieldFromInstruction32(Insn, 12, 4);
1624   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1625 
1626   if (pred == 0xF)
1627     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
1628 
1629   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder)))
1630     return MCDisassembler::Fail;
1631   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
1632     return MCDisassembler::Fail;
1633   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)))
1634     return MCDisassembler::Fail;
1635   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder)))
1636     return MCDisassembler::Fail;
1637 
1638   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1639     return MCDisassembler::Fail;
1640 
1641   return S;
1642 }
1643 
1644 static DecodeStatus DecodeAddrModeImm12Operand(llvm::MCInst &Inst, unsigned Val,
1645                            uint64_t Address, const void *Decoder) {
1646   DecodeStatus S = MCDisassembler::Success;
1647 
1648   unsigned add = fieldFromInstruction32(Val, 12, 1);
1649   unsigned imm = fieldFromInstruction32(Val, 0, 12);
1650   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
1651 
1652   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1653     return MCDisassembler::Fail;
1654 
1655   if (!add) imm *= -1;
1656   if (imm == 0 && !add) imm = INT32_MIN;
1657   Inst.addOperand(MCOperand::CreateImm(imm));
1658 
1659   return S;
1660 }
1661 
1662 static DecodeStatus DecodeAddrMode5Operand(llvm::MCInst &Inst, unsigned Val,
1663                                    uint64_t Address, const void *Decoder) {
1664   DecodeStatus S = MCDisassembler::Success;
1665 
1666   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
1667   unsigned U = fieldFromInstruction32(Val, 8, 1);
1668   unsigned imm = fieldFromInstruction32(Val, 0, 8);
1669 
1670   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
1671     return MCDisassembler::Fail;
1672 
1673   if (U)
1674     Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
1675   else
1676     Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
1677 
1678   return S;
1679 }
1680 
1681 static DecodeStatus DecodeAddrMode7Operand(llvm::MCInst &Inst, unsigned Val,
1682                                    uint64_t Address, const void *Decoder) {
1683   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
1684 }
1685 
1686 static DecodeStatus
1687 DecodeBranchImmInstruction(llvm::MCInst &Inst, unsigned Insn,
1688                            uint64_t Address, const void *Decoder) {
1689   DecodeStatus S = MCDisassembler::Success;
1690 
1691   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1692   unsigned imm = fieldFromInstruction32(Insn, 0, 24) << 2;
1693 
1694   if (pred == 0xF) {
1695     Inst.setOpcode(ARM::BLXi);
1696     imm |= fieldFromInstruction32(Insn, 24, 1) << 1;
1697     Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1698     return S;
1699   }
1700 
1701   Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1702   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
1703     return MCDisassembler::Fail;
1704 
1705   return S;
1706 }
1707 
1708 
1709 static DecodeStatus DecodeVCVTImmOperand(llvm::MCInst &Inst, unsigned Val,
1710                                  uint64_t Address, const void *Decoder) {
1711   Inst.addOperand(MCOperand::CreateImm(64 - Val));
1712   return MCDisassembler::Success;
1713 }
1714 
1715 static DecodeStatus DecodeAddrMode6Operand(llvm::MCInst &Inst, unsigned Val,
1716                                    uint64_t Address, const void *Decoder) {
1717   DecodeStatus S = MCDisassembler::Success;
1718 
1719   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
1720   unsigned align = fieldFromInstruction32(Val, 4, 2);
1721 
1722   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1723     return MCDisassembler::Fail;
1724   if (!align)
1725     Inst.addOperand(MCOperand::CreateImm(0));
1726   else
1727     Inst.addOperand(MCOperand::CreateImm(4 << align));
1728 
1729   return S;
1730 }
1731 
1732 static DecodeStatus DecodeVLDInstruction(llvm::MCInst &Inst, unsigned Insn,
1733                                    uint64_t Address, const void *Decoder) {
1734   DecodeStatus S = MCDisassembler::Success;
1735 
1736   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1737   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1738   unsigned wb = fieldFromInstruction32(Insn, 16, 4);
1739   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1740   Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
1741   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1742 
1743   // First output register
1744   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
1745     return MCDisassembler::Fail;
1746 
1747   // Second output register
1748   switch (Inst.getOpcode()) {
1749     case ARM::VLD1q8:
1750     case ARM::VLD1q16:
1751     case ARM::VLD1q32:
1752     case ARM::VLD1q64:
1753     case ARM::VLD1q8_UPD:
1754     case ARM::VLD1q16_UPD:
1755     case ARM::VLD1q32_UPD:
1756     case ARM::VLD1q64_UPD:
1757     case ARM::VLD1d8T:
1758     case ARM::VLD1d16T:
1759     case ARM::VLD1d32T:
1760     case ARM::VLD1d64T:
1761     case ARM::VLD1d8T_UPD:
1762     case ARM::VLD1d16T_UPD:
1763     case ARM::VLD1d32T_UPD:
1764     case ARM::VLD1d64T_UPD:
1765     case ARM::VLD1d8Q:
1766     case ARM::VLD1d16Q:
1767     case ARM::VLD1d32Q:
1768     case ARM::VLD1d64Q:
1769     case ARM::VLD1d8Q_UPD:
1770     case ARM::VLD1d16Q_UPD:
1771     case ARM::VLD1d32Q_UPD:
1772     case ARM::VLD1d64Q_UPD:
1773     case ARM::VLD2d8:
1774     case ARM::VLD2d16:
1775     case ARM::VLD2d32:
1776     case ARM::VLD2d8_UPD:
1777     case ARM::VLD2d16_UPD:
1778     case ARM::VLD2d32_UPD:
1779     case ARM::VLD2q8:
1780     case ARM::VLD2q16:
1781     case ARM::VLD2q32:
1782     case ARM::VLD2q8_UPD:
1783     case ARM::VLD2q16_UPD:
1784     case ARM::VLD2q32_UPD:
1785     case ARM::VLD3d8:
1786     case ARM::VLD3d16:
1787     case ARM::VLD3d32:
1788     case ARM::VLD3d8_UPD:
1789     case ARM::VLD3d16_UPD:
1790     case ARM::VLD3d32_UPD:
1791     case ARM::VLD4d8:
1792     case ARM::VLD4d16:
1793     case ARM::VLD4d32:
1794     case ARM::VLD4d8_UPD:
1795     case ARM::VLD4d16_UPD:
1796     case ARM::VLD4d32_UPD:
1797       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
1798         return MCDisassembler::Fail;
1799       break;
1800     case ARM::VLD2b8:
1801     case ARM::VLD2b16:
1802     case ARM::VLD2b32:
1803     case ARM::VLD2b8_UPD:
1804     case ARM::VLD2b16_UPD:
1805     case ARM::VLD2b32_UPD:
1806     case ARM::VLD3q8:
1807     case ARM::VLD3q16:
1808     case ARM::VLD3q32:
1809     case ARM::VLD3q8_UPD:
1810     case ARM::VLD3q16_UPD:
1811     case ARM::VLD3q32_UPD:
1812     case ARM::VLD4q8:
1813     case ARM::VLD4q16:
1814     case ARM::VLD4q32:
1815     case ARM::VLD4q8_UPD:
1816     case ARM::VLD4q16_UPD:
1817     case ARM::VLD4q32_UPD:
1818       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
1819         return MCDisassembler::Fail;
1820     default:
1821       break;
1822   }
1823 
1824   // Third output register
1825   switch(Inst.getOpcode()) {
1826     case ARM::VLD1d8T:
1827     case ARM::VLD1d16T:
1828     case ARM::VLD1d32T:
1829     case ARM::VLD1d64T:
1830     case ARM::VLD1d8T_UPD:
1831     case ARM::VLD1d16T_UPD:
1832     case ARM::VLD1d32T_UPD:
1833     case ARM::VLD1d64T_UPD:
1834     case ARM::VLD1d8Q:
1835     case ARM::VLD1d16Q:
1836     case ARM::VLD1d32Q:
1837     case ARM::VLD1d64Q:
1838     case ARM::VLD1d8Q_UPD:
1839     case ARM::VLD1d16Q_UPD:
1840     case ARM::VLD1d32Q_UPD:
1841     case ARM::VLD1d64Q_UPD:
1842     case ARM::VLD2q8:
1843     case ARM::VLD2q16:
1844     case ARM::VLD2q32:
1845     case ARM::VLD2q8_UPD:
1846     case ARM::VLD2q16_UPD:
1847     case ARM::VLD2q32_UPD:
1848     case ARM::VLD3d8:
1849     case ARM::VLD3d16:
1850     case ARM::VLD3d32:
1851     case ARM::VLD3d8_UPD:
1852     case ARM::VLD3d16_UPD:
1853     case ARM::VLD3d32_UPD:
1854     case ARM::VLD4d8:
1855     case ARM::VLD4d16:
1856     case ARM::VLD4d32:
1857     case ARM::VLD4d8_UPD:
1858     case ARM::VLD4d16_UPD:
1859     case ARM::VLD4d32_UPD:
1860       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
1861         return MCDisassembler::Fail;
1862       break;
1863     case ARM::VLD3q8:
1864     case ARM::VLD3q16:
1865     case ARM::VLD3q32:
1866     case ARM::VLD3q8_UPD:
1867     case ARM::VLD3q16_UPD:
1868     case ARM::VLD3q32_UPD:
1869     case ARM::VLD4q8:
1870     case ARM::VLD4q16:
1871     case ARM::VLD4q32:
1872     case ARM::VLD4q8_UPD:
1873     case ARM::VLD4q16_UPD:
1874     case ARM::VLD4q32_UPD:
1875       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
1876         return MCDisassembler::Fail;
1877       break;
1878     default:
1879       break;
1880   }
1881 
1882   // Fourth output register
1883   switch (Inst.getOpcode()) {
1884     case ARM::VLD1d8Q:
1885     case ARM::VLD1d16Q:
1886     case ARM::VLD1d32Q:
1887     case ARM::VLD1d64Q:
1888     case ARM::VLD1d8Q_UPD:
1889     case ARM::VLD1d16Q_UPD:
1890     case ARM::VLD1d32Q_UPD:
1891     case ARM::VLD1d64Q_UPD:
1892     case ARM::VLD2q8:
1893     case ARM::VLD2q16:
1894     case ARM::VLD2q32:
1895     case ARM::VLD2q8_UPD:
1896     case ARM::VLD2q16_UPD:
1897     case ARM::VLD2q32_UPD:
1898     case ARM::VLD4d8:
1899     case ARM::VLD4d16:
1900     case ARM::VLD4d32:
1901     case ARM::VLD4d8_UPD:
1902     case ARM::VLD4d16_UPD:
1903     case ARM::VLD4d32_UPD:
1904       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
1905         return MCDisassembler::Fail;
1906       break;
1907     case ARM::VLD4q8:
1908     case ARM::VLD4q16:
1909     case ARM::VLD4q32:
1910     case ARM::VLD4q8_UPD:
1911     case ARM::VLD4q16_UPD:
1912     case ARM::VLD4q32_UPD:
1913       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
1914         return MCDisassembler::Fail;
1915       break;
1916     default:
1917       break;
1918   }
1919 
1920   // Writeback operand
1921   switch (Inst.getOpcode()) {
1922     case ARM::VLD1d8_UPD:
1923     case ARM::VLD1d16_UPD:
1924     case ARM::VLD1d32_UPD:
1925     case ARM::VLD1d64_UPD:
1926     case ARM::VLD1q8_UPD:
1927     case ARM::VLD1q16_UPD:
1928     case ARM::VLD1q32_UPD:
1929     case ARM::VLD1q64_UPD:
1930     case ARM::VLD1d8T_UPD:
1931     case ARM::VLD1d16T_UPD:
1932     case ARM::VLD1d32T_UPD:
1933     case ARM::VLD1d64T_UPD:
1934     case ARM::VLD1d8Q_UPD:
1935     case ARM::VLD1d16Q_UPD:
1936     case ARM::VLD1d32Q_UPD:
1937     case ARM::VLD1d64Q_UPD:
1938     case ARM::VLD2d8_UPD:
1939     case ARM::VLD2d16_UPD:
1940     case ARM::VLD2d32_UPD:
1941     case ARM::VLD2q8_UPD:
1942     case ARM::VLD2q16_UPD:
1943     case ARM::VLD2q32_UPD:
1944     case ARM::VLD2b8_UPD:
1945     case ARM::VLD2b16_UPD:
1946     case ARM::VLD2b32_UPD:
1947     case ARM::VLD3d8_UPD:
1948     case ARM::VLD3d16_UPD:
1949     case ARM::VLD3d32_UPD:
1950     case ARM::VLD3q8_UPD:
1951     case ARM::VLD3q16_UPD:
1952     case ARM::VLD3q32_UPD:
1953     case ARM::VLD4d8_UPD:
1954     case ARM::VLD4d16_UPD:
1955     case ARM::VLD4d32_UPD:
1956     case ARM::VLD4q8_UPD:
1957     case ARM::VLD4q16_UPD:
1958     case ARM::VLD4q32_UPD:
1959       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
1960         return MCDisassembler::Fail;
1961       break;
1962     default:
1963       break;
1964   }
1965 
1966   // AddrMode6 Base (register+alignment)
1967   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
1968     return MCDisassembler::Fail;
1969 
1970   // AddrMode6 Offset (register)
1971   if (Rm == 0xD)
1972     Inst.addOperand(MCOperand::CreateReg(0));
1973   else if (Rm != 0xF) {
1974     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
1975       return MCDisassembler::Fail;
1976   }
1977 
1978   return S;
1979 }
1980 
1981 static DecodeStatus DecodeVSTInstruction(llvm::MCInst &Inst, unsigned Insn,
1982                                  uint64_t Address, const void *Decoder) {
1983   DecodeStatus S = MCDisassembler::Success;
1984 
1985   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1986   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1987   unsigned wb = fieldFromInstruction32(Insn, 16, 4);
1988   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1989   Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
1990   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1991 
1992   // Writeback Operand
1993   switch (Inst.getOpcode()) {
1994     case ARM::VST1d8_UPD:
1995     case ARM::VST1d16_UPD:
1996     case ARM::VST1d32_UPD:
1997     case ARM::VST1d64_UPD:
1998     case ARM::VST1q8_UPD:
1999     case ARM::VST1q16_UPD:
2000     case ARM::VST1q32_UPD:
2001     case ARM::VST1q64_UPD:
2002     case ARM::VST1d8T_UPD:
2003     case ARM::VST1d16T_UPD:
2004     case ARM::VST1d32T_UPD:
2005     case ARM::VST1d64T_UPD:
2006     case ARM::VST1d8Q_UPD:
2007     case ARM::VST1d16Q_UPD:
2008     case ARM::VST1d32Q_UPD:
2009     case ARM::VST1d64Q_UPD:
2010     case ARM::VST2d8_UPD:
2011     case ARM::VST2d16_UPD:
2012     case ARM::VST2d32_UPD:
2013     case ARM::VST2q8_UPD:
2014     case ARM::VST2q16_UPD:
2015     case ARM::VST2q32_UPD:
2016     case ARM::VST2b8_UPD:
2017     case ARM::VST2b16_UPD:
2018     case ARM::VST2b32_UPD:
2019     case ARM::VST3d8_UPD:
2020     case ARM::VST3d16_UPD:
2021     case ARM::VST3d32_UPD:
2022     case ARM::VST3q8_UPD:
2023     case ARM::VST3q16_UPD:
2024     case ARM::VST3q32_UPD:
2025     case ARM::VST4d8_UPD:
2026     case ARM::VST4d16_UPD:
2027     case ARM::VST4d32_UPD:
2028     case ARM::VST4q8_UPD:
2029     case ARM::VST4q16_UPD:
2030     case ARM::VST4q32_UPD:
2031       if (!Check(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder)))
2032         return MCDisassembler::Fail;
2033       break;
2034     default:
2035       break;
2036   }
2037 
2038   // AddrMode6 Base (register+alignment)
2039   if (!Check(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)))
2040     return MCDisassembler::Fail;
2041 
2042   // AddrMode6 Offset (register)
2043   if (Rm == 0xD)
2044     Inst.addOperand(MCOperand::CreateReg(0));
2045   else if (Rm != 0xF) {
2046     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2047     return MCDisassembler::Fail;
2048   }
2049 
2050   // First input register
2051   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2052     return MCDisassembler::Fail;
2053 
2054   // Second input register
2055   switch (Inst.getOpcode()) {
2056     case ARM::VST1q8:
2057     case ARM::VST1q16:
2058     case ARM::VST1q32:
2059     case ARM::VST1q64:
2060     case ARM::VST1q8_UPD:
2061     case ARM::VST1q16_UPD:
2062     case ARM::VST1q32_UPD:
2063     case ARM::VST1q64_UPD:
2064     case ARM::VST1d8T:
2065     case ARM::VST1d16T:
2066     case ARM::VST1d32T:
2067     case ARM::VST1d64T:
2068     case ARM::VST1d8T_UPD:
2069     case ARM::VST1d16T_UPD:
2070     case ARM::VST1d32T_UPD:
2071     case ARM::VST1d64T_UPD:
2072     case ARM::VST1d8Q:
2073     case ARM::VST1d16Q:
2074     case ARM::VST1d32Q:
2075     case ARM::VST1d64Q:
2076     case ARM::VST1d8Q_UPD:
2077     case ARM::VST1d16Q_UPD:
2078     case ARM::VST1d32Q_UPD:
2079     case ARM::VST1d64Q_UPD:
2080     case ARM::VST2d8:
2081     case ARM::VST2d16:
2082     case ARM::VST2d32:
2083     case ARM::VST2d8_UPD:
2084     case ARM::VST2d16_UPD:
2085     case ARM::VST2d32_UPD:
2086     case ARM::VST2q8:
2087     case ARM::VST2q16:
2088     case ARM::VST2q32:
2089     case ARM::VST2q8_UPD:
2090     case ARM::VST2q16_UPD:
2091     case ARM::VST2q32_UPD:
2092     case ARM::VST3d8:
2093     case ARM::VST3d16:
2094     case ARM::VST3d32:
2095     case ARM::VST3d8_UPD:
2096     case ARM::VST3d16_UPD:
2097     case ARM::VST3d32_UPD:
2098     case ARM::VST4d8:
2099     case ARM::VST4d16:
2100     case ARM::VST4d32:
2101     case ARM::VST4d8_UPD:
2102     case ARM::VST4d16_UPD:
2103     case ARM::VST4d32_UPD:
2104       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2105         return MCDisassembler::Fail;
2106       break;
2107     case ARM::VST2b8:
2108     case ARM::VST2b16:
2109     case ARM::VST2b32:
2110     case ARM::VST2b8_UPD:
2111     case ARM::VST2b16_UPD:
2112     case ARM::VST2b32_UPD:
2113     case ARM::VST3q8:
2114     case ARM::VST3q16:
2115     case ARM::VST3q32:
2116     case ARM::VST3q8_UPD:
2117     case ARM::VST3q16_UPD:
2118     case ARM::VST3q32_UPD:
2119     case ARM::VST4q8:
2120     case ARM::VST4q16:
2121     case ARM::VST4q32:
2122     case ARM::VST4q8_UPD:
2123     case ARM::VST4q16_UPD:
2124     case ARM::VST4q32_UPD:
2125       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2126         return MCDisassembler::Fail;
2127       break;
2128     default:
2129       break;
2130   }
2131 
2132   // Third input register
2133   switch (Inst.getOpcode()) {
2134     case ARM::VST1d8T:
2135     case ARM::VST1d16T:
2136     case ARM::VST1d32T:
2137     case ARM::VST1d64T:
2138     case ARM::VST1d8T_UPD:
2139     case ARM::VST1d16T_UPD:
2140     case ARM::VST1d32T_UPD:
2141     case ARM::VST1d64T_UPD:
2142     case ARM::VST1d8Q:
2143     case ARM::VST1d16Q:
2144     case ARM::VST1d32Q:
2145     case ARM::VST1d64Q:
2146     case ARM::VST1d8Q_UPD:
2147     case ARM::VST1d16Q_UPD:
2148     case ARM::VST1d32Q_UPD:
2149     case ARM::VST1d64Q_UPD:
2150     case ARM::VST2q8:
2151     case ARM::VST2q16:
2152     case ARM::VST2q32:
2153     case ARM::VST2q8_UPD:
2154     case ARM::VST2q16_UPD:
2155     case ARM::VST2q32_UPD:
2156     case ARM::VST3d8:
2157     case ARM::VST3d16:
2158     case ARM::VST3d32:
2159     case ARM::VST3d8_UPD:
2160     case ARM::VST3d16_UPD:
2161     case ARM::VST3d32_UPD:
2162     case ARM::VST4d8:
2163     case ARM::VST4d16:
2164     case ARM::VST4d32:
2165     case ARM::VST4d8_UPD:
2166     case ARM::VST4d16_UPD:
2167     case ARM::VST4d32_UPD:
2168       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)))
2169         return MCDisassembler::Fail;
2170       break;
2171     case ARM::VST3q8:
2172     case ARM::VST3q16:
2173     case ARM::VST3q32:
2174     case ARM::VST3q8_UPD:
2175     case ARM::VST3q16_UPD:
2176     case ARM::VST3q32_UPD:
2177     case ARM::VST4q8:
2178     case ARM::VST4q16:
2179     case ARM::VST4q32:
2180     case ARM::VST4q8_UPD:
2181     case ARM::VST4q16_UPD:
2182     case ARM::VST4q32_UPD:
2183       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)))
2184         return MCDisassembler::Fail;
2185       break;
2186     default:
2187       break;
2188   }
2189 
2190   // Fourth input register
2191   switch (Inst.getOpcode()) {
2192     case ARM::VST1d8Q:
2193     case ARM::VST1d16Q:
2194     case ARM::VST1d32Q:
2195     case ARM::VST1d64Q:
2196     case ARM::VST1d8Q_UPD:
2197     case ARM::VST1d16Q_UPD:
2198     case ARM::VST1d32Q_UPD:
2199     case ARM::VST1d64Q_UPD:
2200     case ARM::VST2q8:
2201     case ARM::VST2q16:
2202     case ARM::VST2q32:
2203     case ARM::VST2q8_UPD:
2204     case ARM::VST2q16_UPD:
2205     case ARM::VST2q32_UPD:
2206     case ARM::VST4d8:
2207     case ARM::VST4d16:
2208     case ARM::VST4d32:
2209     case ARM::VST4d8_UPD:
2210     case ARM::VST4d16_UPD:
2211     case ARM::VST4d32_UPD:
2212       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)))
2213         return MCDisassembler::Fail;
2214       break;
2215     case ARM::VST4q8:
2216     case ARM::VST4q16:
2217     case ARM::VST4q32:
2218     case ARM::VST4q8_UPD:
2219     case ARM::VST4q16_UPD:
2220     case ARM::VST4q32_UPD:
2221       if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)))
2222         return MCDisassembler::Fail;
2223       break;
2224     default:
2225       break;
2226   }
2227 
2228   return S;
2229 }
2230 
2231 static DecodeStatus DecodeVLD1DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2232                                     uint64_t Address, const void *Decoder) {
2233   DecodeStatus S = MCDisassembler::Success;
2234 
2235   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2236   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2237   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2238   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2239   unsigned align = fieldFromInstruction32(Insn, 4, 1);
2240   unsigned size = fieldFromInstruction32(Insn, 6, 2);
2241   unsigned regs = fieldFromInstruction32(Insn, 5, 1) + 1;
2242 
2243   align *= (1 << size);
2244 
2245   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2246     return MCDisassembler::Fail;
2247   if (regs == 2) {
2248     if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)))
2249       return MCDisassembler::Fail;
2250   }
2251   if (Rm != 0xF) {
2252     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2253       return MCDisassembler::Fail;
2254   }
2255 
2256   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2257     return MCDisassembler::Fail;
2258   Inst.addOperand(MCOperand::CreateImm(align));
2259 
2260   if (Rm == 0xD)
2261     Inst.addOperand(MCOperand::CreateReg(0));
2262   else if (Rm != 0xF) {
2263     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2264       return MCDisassembler::Fail;
2265   }
2266 
2267   return S;
2268 }
2269 
2270 static DecodeStatus DecodeVLD2DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2271                                     uint64_t Address, const void *Decoder) {
2272   DecodeStatus S = MCDisassembler::Success;
2273 
2274   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2275   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2276   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2277   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2278   unsigned align = fieldFromInstruction32(Insn, 4, 1);
2279   unsigned size = 1 << fieldFromInstruction32(Insn, 6, 2);
2280   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2281   align *= 2*size;
2282 
2283   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2284     return MCDisassembler::Fail;
2285   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
2286     return MCDisassembler::Fail;
2287   if (Rm != 0xF) {
2288     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2289       return MCDisassembler::Fail;
2290   }
2291 
2292   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2293     return MCDisassembler::Fail;
2294   Inst.addOperand(MCOperand::CreateImm(align));
2295 
2296   if (Rm == 0xD)
2297     Inst.addOperand(MCOperand::CreateReg(0));
2298   else if (Rm != 0xF) {
2299     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2300       return MCDisassembler::Fail;
2301   }
2302 
2303   return S;
2304 }
2305 
2306 static DecodeStatus DecodeVLD3DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2307                                     uint64_t Address, const void *Decoder) {
2308   DecodeStatus S = MCDisassembler::Success;
2309 
2310   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2311   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2312   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2313   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2314   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2315 
2316   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2317     return MCDisassembler::Fail;
2318   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
2319     return MCDisassembler::Fail;
2320   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
2321     return MCDisassembler::Fail;
2322   if (Rm != 0xF) {
2323     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2324       return MCDisassembler::Fail;
2325   }
2326 
2327   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2328     return MCDisassembler::Fail;
2329   Inst.addOperand(MCOperand::CreateImm(0));
2330 
2331   if (Rm == 0xD)
2332     Inst.addOperand(MCOperand::CreateReg(0));
2333   else if (Rm != 0xF) {
2334     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2335       return MCDisassembler::Fail;
2336   }
2337 
2338   return S;
2339 }
2340 
2341 static DecodeStatus DecodeVLD4DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2342                                     uint64_t Address, const void *Decoder) {
2343   DecodeStatus S = MCDisassembler::Success;
2344 
2345   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2346   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2347   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2348   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2349   unsigned size = fieldFromInstruction32(Insn, 6, 2);
2350   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2351   unsigned align = fieldFromInstruction32(Insn, 4, 1);
2352 
2353   if (size == 0x3) {
2354     size = 4;
2355     align = 16;
2356   } else {
2357     if (size == 2) {
2358       size = 1 << size;
2359       align *= 8;
2360     } else {
2361       size = 1 << size;
2362       align *= 4*size;
2363     }
2364   }
2365 
2366   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2367     return MCDisassembler::Fail;
2368   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)))
2369     return MCDisassembler::Fail;
2370   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder)))
2371     return MCDisassembler::Fail;
2372   if (!Check(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder)))
2373     return MCDisassembler::Fail;
2374   if (Rm != 0xF) {
2375     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2376       return MCDisassembler::Fail;
2377   }
2378 
2379   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2380     return MCDisassembler::Fail;
2381   Inst.addOperand(MCOperand::CreateImm(align));
2382 
2383   if (Rm == 0xD)
2384     Inst.addOperand(MCOperand::CreateReg(0));
2385   else if (Rm != 0xF) {
2386     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2387       return MCDisassembler::Fail;
2388   }
2389 
2390   return S;
2391 }
2392 
2393 static DecodeStatus
2394 DecodeNEONModImmInstruction(llvm::MCInst &Inst, unsigned Insn,
2395                             uint64_t Address, const void *Decoder) {
2396   DecodeStatus S = MCDisassembler::Success;
2397 
2398   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2399   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2400   unsigned imm = fieldFromInstruction32(Insn, 0, 4);
2401   imm |= fieldFromInstruction32(Insn, 16, 3) << 4;
2402   imm |= fieldFromInstruction32(Insn, 24, 1) << 7;
2403   imm |= fieldFromInstruction32(Insn, 8, 4) << 8;
2404   imm |= fieldFromInstruction32(Insn, 5, 1) << 12;
2405   unsigned Q = fieldFromInstruction32(Insn, 6, 1);
2406 
2407   if (Q) {
2408     if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
2409     return MCDisassembler::Fail;
2410   } else {
2411     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2412     return MCDisassembler::Fail;
2413   }
2414 
2415   Inst.addOperand(MCOperand::CreateImm(imm));
2416 
2417   switch (Inst.getOpcode()) {
2418     case ARM::VORRiv4i16:
2419     case ARM::VORRiv2i32:
2420     case ARM::VBICiv4i16:
2421     case ARM::VBICiv2i32:
2422       if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2423         return MCDisassembler::Fail;
2424       break;
2425     case ARM::VORRiv8i16:
2426     case ARM::VORRiv4i32:
2427     case ARM::VBICiv8i16:
2428     case ARM::VBICiv4i32:
2429       if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
2430         return MCDisassembler::Fail;
2431       break;
2432     default:
2433       break;
2434   }
2435 
2436   return S;
2437 }
2438 
2439 static DecodeStatus DecodeVSHLMaxInstruction(llvm::MCInst &Inst, unsigned Insn,
2440                                         uint64_t Address, const void *Decoder) {
2441   DecodeStatus S = MCDisassembler::Success;
2442 
2443   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2444   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2445   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2446   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2447   unsigned size = fieldFromInstruction32(Insn, 18, 2);
2448 
2449   if (!Check(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)))
2450     return MCDisassembler::Fail;
2451   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
2452     return MCDisassembler::Fail;
2453   Inst.addOperand(MCOperand::CreateImm(8 << size));
2454 
2455   return S;
2456 }
2457 
2458 static DecodeStatus DecodeShiftRight8Imm(llvm::MCInst &Inst, unsigned Val,
2459                                uint64_t Address, const void *Decoder) {
2460   Inst.addOperand(MCOperand::CreateImm(8 - Val));
2461   return MCDisassembler::Success;
2462 }
2463 
2464 static DecodeStatus DecodeShiftRight16Imm(llvm::MCInst &Inst, unsigned Val,
2465                                uint64_t Address, const void *Decoder) {
2466   Inst.addOperand(MCOperand::CreateImm(16 - Val));
2467   return MCDisassembler::Success;
2468 }
2469 
2470 static DecodeStatus DecodeShiftRight32Imm(llvm::MCInst &Inst, unsigned Val,
2471                                uint64_t Address, const void *Decoder) {
2472   Inst.addOperand(MCOperand::CreateImm(32 - Val));
2473   return MCDisassembler::Success;
2474 }
2475 
2476 static DecodeStatus DecodeShiftRight64Imm(llvm::MCInst &Inst, unsigned Val,
2477                                uint64_t Address, const void *Decoder) {
2478   Inst.addOperand(MCOperand::CreateImm(64 - Val));
2479   return MCDisassembler::Success;
2480 }
2481 
2482 static DecodeStatus DecodeTBLInstruction(llvm::MCInst &Inst, unsigned Insn,
2483                                uint64_t Address, const void *Decoder) {
2484   DecodeStatus S = MCDisassembler::Success;
2485 
2486   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2487   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2488   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2489   Rn |= fieldFromInstruction32(Insn, 7, 1) << 4;
2490   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2491   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2492   unsigned op = fieldFromInstruction32(Insn, 6, 1);
2493   unsigned length = fieldFromInstruction32(Insn, 8, 2) + 1;
2494 
2495   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2496     return MCDisassembler::Fail;
2497   if (op) {
2498     if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
2499     return MCDisassembler::Fail; // Writeback
2500   }
2501 
2502   for (unsigned i = 0; i < length; ++i) {
2503     if (!Check(S, DecodeDPRRegisterClass(Inst, (Rn+i)%32, Address, Decoder)))
2504     return MCDisassembler::Fail;
2505   }
2506 
2507   if (!Check(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)))
2508     return MCDisassembler::Fail;
2509 
2510   return S;
2511 }
2512 
2513 static DecodeStatus DecodeVFPfpImm(llvm::MCInst &Inst, unsigned Val,
2514                             uint64_t Address, const void *Decoder) {
2515   // The immediate needs to be a fully instantiated float.  However, the
2516   // auto-generated decoder is only able to fill in some of the bits
2517   // necessary.  For instance, the 'b' bit is replicated multiple times,
2518   // and is even present in inverted form in one bit.  We do a little
2519   // binary parsing here to fill in those missing bits, and then
2520   // reinterpret it all as a float.
2521   union {
2522     uint32_t integer;
2523     float fp;
2524   } fp_conv;
2525 
2526   fp_conv.integer = Val;
2527   uint32_t b = fieldFromInstruction32(Val, 25, 1);
2528   fp_conv.integer |= b << 26;
2529   fp_conv.integer |= b << 27;
2530   fp_conv.integer |= b << 28;
2531   fp_conv.integer |= b << 29;
2532   fp_conv.integer |= (~b & 0x1) << 30;
2533 
2534   Inst.addOperand(MCOperand::CreateFPImm(fp_conv.fp));
2535   return MCDisassembler::Success;
2536 }
2537 
2538 static DecodeStatus DecodeThumbAddSpecialReg(llvm::MCInst &Inst, uint16_t Insn,
2539                                      uint64_t Address, const void *Decoder) {
2540   DecodeStatus S = MCDisassembler::Success;
2541 
2542   unsigned dst = fieldFromInstruction16(Insn, 8, 3);
2543   unsigned imm = fieldFromInstruction16(Insn, 0, 8);
2544 
2545   if (!Check(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder)))
2546     return MCDisassembler::Fail;
2547 
2548   switch(Inst.getOpcode()) {
2549     default:
2550       return MCDisassembler::Fail;
2551     case ARM::tADR:
2552       break; // tADR does not explicitly represent the PC as an operand.
2553     case ARM::tADDrSPi:
2554       Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2555       break;
2556   }
2557 
2558   Inst.addOperand(MCOperand::CreateImm(imm));
2559   return S;
2560 }
2561 
2562 static DecodeStatus DecodeThumbBROperand(llvm::MCInst &Inst, unsigned Val,
2563                                  uint64_t Address, const void *Decoder) {
2564   Inst.addOperand(MCOperand::CreateImm(SignExtend32<12>(Val << 1)));
2565   return MCDisassembler::Success;
2566 }
2567 
2568 static DecodeStatus DecodeT2BROperand(llvm::MCInst &Inst, unsigned Val,
2569                                  uint64_t Address, const void *Decoder) {
2570   Inst.addOperand(MCOperand::CreateImm(SignExtend32<21>(Val)));
2571   return MCDisassembler::Success;
2572 }
2573 
2574 static DecodeStatus DecodeThumbCmpBROperand(llvm::MCInst &Inst, unsigned Val,
2575                                  uint64_t Address, const void *Decoder) {
2576   Inst.addOperand(MCOperand::CreateImm(SignExtend32<7>(Val << 1)));
2577   return MCDisassembler::Success;
2578 }
2579 
2580 static DecodeStatus DecodeThumbAddrModeRR(llvm::MCInst &Inst, unsigned Val,
2581                                  uint64_t Address, const void *Decoder) {
2582   DecodeStatus S = MCDisassembler::Success;
2583 
2584   unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2585   unsigned Rm = fieldFromInstruction32(Val, 3, 3);
2586 
2587   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
2588     return MCDisassembler::Fail;
2589   if (!Check(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder)))
2590     return MCDisassembler::Fail;
2591 
2592   return S;
2593 }
2594 
2595 static DecodeStatus DecodeThumbAddrModeIS(llvm::MCInst &Inst, unsigned Val,
2596                                   uint64_t Address, const void *Decoder) {
2597   DecodeStatus S = MCDisassembler::Success;
2598 
2599   unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2600   unsigned imm = fieldFromInstruction32(Val, 3, 5);
2601 
2602   if (!Check(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)))
2603     return MCDisassembler::Fail;
2604   Inst.addOperand(MCOperand::CreateImm(imm));
2605 
2606   return S;
2607 }
2608 
2609 static DecodeStatus DecodeThumbAddrModePC(llvm::MCInst &Inst, unsigned Val,
2610                                   uint64_t Address, const void *Decoder) {
2611   Inst.addOperand(MCOperand::CreateImm(Val << 2));
2612 
2613   return MCDisassembler::Success;
2614 }
2615 
2616 static DecodeStatus DecodeThumbAddrModeSP(llvm::MCInst &Inst, unsigned Val,
2617                                   uint64_t Address, const void *Decoder) {
2618   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2619   Inst.addOperand(MCOperand::CreateImm(Val));
2620 
2621   return MCDisassembler::Success;
2622 }
2623 
2624 static DecodeStatus DecodeT2AddrModeSOReg(llvm::MCInst &Inst, unsigned Val,
2625                                   uint64_t Address, const void *Decoder) {
2626   DecodeStatus S = MCDisassembler::Success;
2627 
2628   unsigned Rn = fieldFromInstruction32(Val, 6, 4);
2629   unsigned Rm = fieldFromInstruction32(Val, 2, 4);
2630   unsigned imm = fieldFromInstruction32(Val, 0, 2);
2631 
2632   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2633     return MCDisassembler::Fail;
2634   if (!Check(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder)))
2635     return MCDisassembler::Fail;
2636   Inst.addOperand(MCOperand::CreateImm(imm));
2637 
2638   return S;
2639 }
2640 
2641 static DecodeStatus DecodeT2LoadShift(llvm::MCInst &Inst, unsigned Insn,
2642                               uint64_t Address, const void *Decoder) {
2643   DecodeStatus S = MCDisassembler::Success;
2644 
2645   switch (Inst.getOpcode()) {
2646     case ARM::t2PLDs:
2647     case ARM::t2PLDWs:
2648     case ARM::t2PLIs:
2649       break;
2650     default: {
2651       unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2652       if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2653     return MCDisassembler::Fail;
2654     }
2655   }
2656 
2657   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2658   if (Rn == 0xF) {
2659     switch (Inst.getOpcode()) {
2660       case ARM::t2LDRBs:
2661         Inst.setOpcode(ARM::t2LDRBpci);
2662         break;
2663       case ARM::t2LDRHs:
2664         Inst.setOpcode(ARM::t2LDRHpci);
2665         break;
2666       case ARM::t2LDRSHs:
2667         Inst.setOpcode(ARM::t2LDRSHpci);
2668         break;
2669       case ARM::t2LDRSBs:
2670         Inst.setOpcode(ARM::t2LDRSBpci);
2671         break;
2672       case ARM::t2PLDs:
2673         Inst.setOpcode(ARM::t2PLDi12);
2674         Inst.addOperand(MCOperand::CreateReg(ARM::PC));
2675         break;
2676       default:
2677         return MCDisassembler::Fail;
2678     }
2679 
2680     int imm = fieldFromInstruction32(Insn, 0, 12);
2681     if (!fieldFromInstruction32(Insn, 23, 1)) imm *= -1;
2682     Inst.addOperand(MCOperand::CreateImm(imm));
2683 
2684     return S;
2685   }
2686 
2687   unsigned addrmode = fieldFromInstruction32(Insn, 4, 2);
2688   addrmode |= fieldFromInstruction32(Insn, 0, 4) << 2;
2689   addrmode |= fieldFromInstruction32(Insn, 16, 4) << 6;
2690   if (!Check(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder)))
2691     return MCDisassembler::Fail;
2692 
2693   return S;
2694 }
2695 
2696 static DecodeStatus DecodeT2Imm8S4(llvm::MCInst &Inst, unsigned Val,
2697                            uint64_t Address, const void *Decoder) {
2698   int imm = Val & 0xFF;
2699   if (!(Val & 0x100)) imm *= -1;
2700   Inst.addOperand(MCOperand::CreateImm(imm << 2));
2701 
2702   return MCDisassembler::Success;
2703 }
2704 
2705 static DecodeStatus DecodeT2AddrModeImm8s4(llvm::MCInst &Inst, unsigned Val,
2706                                    uint64_t Address, const void *Decoder) {
2707   DecodeStatus S = MCDisassembler::Success;
2708 
2709   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2710   unsigned imm = fieldFromInstruction32(Val, 0, 9);
2711 
2712   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2713     return MCDisassembler::Fail;
2714   if (!Check(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder)))
2715     return MCDisassembler::Fail;
2716 
2717   return S;
2718 }
2719 
2720 static DecodeStatus DecodeT2AddrModeImm0_1020s4(llvm::MCInst &Inst,unsigned Val,
2721                                    uint64_t Address, const void *Decoder) {
2722   DecodeStatus S = MCDisassembler::Success;
2723 
2724   unsigned Rn = fieldFromInstruction32(Val, 8, 4);
2725   unsigned imm = fieldFromInstruction32(Val, 0, 8);
2726 
2727   if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder)))
2728     return MCDisassembler::Fail;
2729 
2730   Inst.addOperand(MCOperand::CreateImm(imm));
2731 
2732   return S;
2733 }
2734 
2735 static DecodeStatus DecodeT2Imm8(llvm::MCInst &Inst, unsigned Val,
2736                          uint64_t Address, const void *Decoder) {
2737   int imm = Val & 0xFF;
2738   if (Val == 0)
2739     imm = INT32_MIN;
2740   else if (!(Val & 0x100))
2741     imm *= -1;
2742   Inst.addOperand(MCOperand::CreateImm(imm));
2743 
2744   return MCDisassembler::Success;
2745 }
2746 
2747 
2748 static DecodeStatus DecodeT2AddrModeImm8(llvm::MCInst &Inst, unsigned Val,
2749                                  uint64_t Address, const void *Decoder) {
2750   DecodeStatus S = MCDisassembler::Success;
2751 
2752   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2753   unsigned imm = fieldFromInstruction32(Val, 0, 9);
2754 
2755   // Some instructions always use an additive offset.
2756   switch (Inst.getOpcode()) {
2757     case ARM::t2LDRT:
2758     case ARM::t2LDRBT:
2759     case ARM::t2LDRHT:
2760     case ARM::t2LDRSBT:
2761     case ARM::t2LDRSHT:
2762       imm |= 0x100;
2763       break;
2764     default:
2765       break;
2766   }
2767 
2768   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2769     return MCDisassembler::Fail;
2770   if (!Check(S, DecodeT2Imm8(Inst, imm, Address, Decoder)))
2771     return MCDisassembler::Fail;
2772 
2773   return S;
2774 }
2775 
2776 static DecodeStatus DecodeT2LdStPre(llvm::MCInst &Inst, unsigned Insn,
2777                                     uint64_t Address, const void *Decoder) {
2778   DecodeStatus S = MCDisassembler::Success;
2779 
2780   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2781   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2782   unsigned addr = fieldFromInstruction32(Insn, 0, 8);
2783   addr |= fieldFromInstruction32(Insn, 9, 1) << 8;
2784   addr |= Rn << 9;
2785   unsigned load = fieldFromInstruction32(Insn, 20, 1);
2786 
2787   if (!load) {
2788     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2789       return MCDisassembler::Fail;
2790   }
2791 
2792   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
2793     return MCDisassembler::Fail;
2794 
2795   if (load) {
2796     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2797       return MCDisassembler::Fail;
2798   }
2799 
2800   if (!Check(S, DecodeT2AddrModeImm8(Inst, addr, Address, Decoder)))
2801     return MCDisassembler::Fail;
2802 
2803   return S;
2804 }
2805 
2806 static DecodeStatus DecodeT2AddrModeImm12(llvm::MCInst &Inst, unsigned Val,
2807                                   uint64_t Address, const void *Decoder) {
2808   DecodeStatus S = MCDisassembler::Success;
2809 
2810   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
2811   unsigned imm = fieldFromInstruction32(Val, 0, 12);
2812 
2813   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
2814     return MCDisassembler::Fail;
2815   Inst.addOperand(MCOperand::CreateImm(imm));
2816 
2817   return S;
2818 }
2819 
2820 
2821 static DecodeStatus DecodeThumbAddSPImm(llvm::MCInst &Inst, uint16_t Insn,
2822                                 uint64_t Address, const void *Decoder) {
2823   unsigned imm = fieldFromInstruction16(Insn, 0, 7);
2824 
2825   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2826   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2827   Inst.addOperand(MCOperand::CreateImm(imm));
2828 
2829   return MCDisassembler::Success;
2830 }
2831 
2832 static DecodeStatus DecodeThumbAddSPReg(llvm::MCInst &Inst, uint16_t Insn,
2833                                 uint64_t Address, const void *Decoder) {
2834   DecodeStatus S = MCDisassembler::Success;
2835 
2836   if (Inst.getOpcode() == ARM::tADDrSP) {
2837     unsigned Rdm = fieldFromInstruction16(Insn, 0, 3);
2838     Rdm |= fieldFromInstruction16(Insn, 7, 1) << 3;
2839 
2840     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
2841     return MCDisassembler::Fail;
2842     if (!Check(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)))
2843     return MCDisassembler::Fail;
2844     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2845   } else if (Inst.getOpcode() == ARM::tADDspr) {
2846     unsigned Rm = fieldFromInstruction16(Insn, 3, 4);
2847 
2848     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2849     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2850     if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2851     return MCDisassembler::Fail;
2852   }
2853 
2854   return S;
2855 }
2856 
2857 static DecodeStatus DecodeThumbCPS(llvm::MCInst &Inst, uint16_t Insn,
2858                            uint64_t Address, const void *Decoder) {
2859   unsigned imod = fieldFromInstruction16(Insn, 4, 1) | 0x2;
2860   unsigned flags = fieldFromInstruction16(Insn, 0, 3);
2861 
2862   Inst.addOperand(MCOperand::CreateImm(imod));
2863   Inst.addOperand(MCOperand::CreateImm(flags));
2864 
2865   return MCDisassembler::Success;
2866 }
2867 
2868 static DecodeStatus DecodePostIdxReg(llvm::MCInst &Inst, unsigned Insn,
2869                              uint64_t Address, const void *Decoder) {
2870   DecodeStatus S = MCDisassembler::Success;
2871   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2872   unsigned add = fieldFromInstruction32(Insn, 4, 1);
2873 
2874   if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
2875     return MCDisassembler::Fail;
2876   Inst.addOperand(MCOperand::CreateImm(add));
2877 
2878   return S;
2879 }
2880 
2881 static DecodeStatus DecodeThumbBLXOffset(llvm::MCInst &Inst, unsigned Val,
2882                                  uint64_t Address, const void *Decoder) {
2883   Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
2884   return MCDisassembler::Success;
2885 }
2886 
2887 static DecodeStatus DecodeCoprocessor(llvm::MCInst &Inst, unsigned Val,
2888                               uint64_t Address, const void *Decoder) {
2889   if (Val == 0xA || Val == 0xB)
2890     return MCDisassembler::Fail;
2891 
2892   Inst.addOperand(MCOperand::CreateImm(Val));
2893   return MCDisassembler::Success;
2894 }
2895 
2896 static DecodeStatus
2897 DecodeThumb2BCCInstruction(llvm::MCInst &Inst, unsigned Insn,
2898                            uint64_t Address, const void *Decoder) {
2899   DecodeStatus S = MCDisassembler::Success;
2900 
2901   unsigned pred = fieldFromInstruction32(Insn, 22, 4);
2902   if (pred == 0xE || pred == 0xF) {
2903     unsigned opc = fieldFromInstruction32(Insn, 4, 28);
2904     switch (opc) {
2905       default:
2906         return MCDisassembler::Fail;
2907       case 0xf3bf8f4:
2908         Inst.setOpcode(ARM::t2DSB);
2909         break;
2910       case 0xf3bf8f5:
2911         Inst.setOpcode(ARM::t2DMB);
2912         break;
2913       case 0xf3bf8f6:
2914         Inst.setOpcode(ARM::t2ISB);
2915         break;
2916     }
2917 
2918     unsigned imm = fieldFromInstruction32(Insn, 0, 4);
2919     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
2920   }
2921 
2922   unsigned brtarget = fieldFromInstruction32(Insn, 0, 11) << 1;
2923   brtarget |= fieldFromInstruction32(Insn, 11, 1) << 19;
2924   brtarget |= fieldFromInstruction32(Insn, 13, 1) << 18;
2925   brtarget |= fieldFromInstruction32(Insn, 16, 6) << 12;
2926   brtarget |= fieldFromInstruction32(Insn, 26, 1) << 20;
2927 
2928   if (!Check(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder)))
2929     return MCDisassembler::Fail;
2930   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
2931     return MCDisassembler::Fail;
2932 
2933   return S;
2934 }
2935 
2936 // Decode a shifted immediate operand.  These basically consist
2937 // of an 8-bit value, and a 4-bit directive that specifies either
2938 // a splat operation or a rotation.
2939 static DecodeStatus DecodeT2SOImm(llvm::MCInst &Inst, unsigned Val,
2940                           uint64_t Address, const void *Decoder) {
2941   unsigned ctrl = fieldFromInstruction32(Val, 10, 2);
2942   if (ctrl == 0) {
2943     unsigned byte = fieldFromInstruction32(Val, 8, 2);
2944     unsigned imm = fieldFromInstruction32(Val, 0, 8);
2945     switch (byte) {
2946       case 0:
2947         Inst.addOperand(MCOperand::CreateImm(imm));
2948         break;
2949       case 1:
2950         Inst.addOperand(MCOperand::CreateImm((imm << 16) | imm));
2951         break;
2952       case 2:
2953         Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 8)));
2954         break;
2955       case 3:
2956         Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 16) |
2957                                              (imm << 8)  |  imm));
2958         break;
2959     }
2960   } else {
2961     unsigned unrot = fieldFromInstruction32(Val, 0, 7) | 0x80;
2962     unsigned rot = fieldFromInstruction32(Val, 7, 5);
2963     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
2964     Inst.addOperand(MCOperand::CreateImm(imm));
2965   }
2966 
2967   return MCDisassembler::Success;
2968 }
2969 
2970 static DecodeStatus
2971 DecodeThumbBCCTargetOperand(llvm::MCInst &Inst, unsigned Val,
2972                             uint64_t Address, const void *Decoder){
2973   Inst.addOperand(MCOperand::CreateImm(Val << 1));
2974   return MCDisassembler::Success;
2975 }
2976 
2977 static DecodeStatus DecodeThumbBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
2978                                        uint64_t Address, const void *Decoder){
2979   Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
2980   return MCDisassembler::Success;
2981 }
2982 
2983 static DecodeStatus DecodeMemBarrierOption(llvm::MCInst &Inst, unsigned Val,
2984                                    uint64_t Address, const void *Decoder) {
2985   switch (Val) {
2986   default:
2987     return MCDisassembler::Fail;
2988   case 0xF: // SY
2989   case 0xE: // ST
2990   case 0xB: // ISH
2991   case 0xA: // ISHST
2992   case 0x7: // NSH
2993   case 0x6: // NSHST
2994   case 0x3: // OSH
2995   case 0x2: // OSHST
2996     break;
2997   }
2998 
2999   Inst.addOperand(MCOperand::CreateImm(Val));
3000   return MCDisassembler::Success;
3001 }
3002 
3003 static DecodeStatus DecodeMSRMask(llvm::MCInst &Inst, unsigned Val,
3004                           uint64_t Address, const void *Decoder) {
3005   if (!Val) return MCDisassembler::Fail;
3006   Inst.addOperand(MCOperand::CreateImm(Val));
3007   return MCDisassembler::Success;
3008 }
3009 
3010 static DecodeStatus DecodeDoubleRegLoad(llvm::MCInst &Inst, unsigned Insn,
3011                                         uint64_t Address, const void *Decoder) {
3012   DecodeStatus S = MCDisassembler::Success;
3013 
3014   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3015   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3016   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3017 
3018   if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return MCDisassembler::Fail;
3019 
3020   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3021     return MCDisassembler::Fail;
3022   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
3023     return MCDisassembler::Fail;
3024   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3025     return MCDisassembler::Fail;
3026   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3027     return MCDisassembler::Fail;
3028 
3029   return S;
3030 }
3031 
3032 
3033 static DecodeStatus DecodeDoubleRegStore(llvm::MCInst &Inst, unsigned Insn,
3034                                          uint64_t Address, const void *Decoder){
3035   DecodeStatus S = MCDisassembler::Success;
3036 
3037   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3038   unsigned Rt = fieldFromInstruction32(Insn, 0, 4);
3039   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3040   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3041 
3042   if (!Check(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)))
3043     return MCDisassembler::Fail;
3044 
3045   if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return MCDisassembler::Fail;
3046   if (Rd == Rn || Rd == Rt || Rd == Rt+1) return MCDisassembler::Fail;
3047 
3048   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3049     return MCDisassembler::Fail;
3050   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)))
3051     return MCDisassembler::Fail;
3052   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3053     return MCDisassembler::Fail;
3054   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3055     return MCDisassembler::Fail;
3056 
3057   return S;
3058 }
3059 
3060 static DecodeStatus DecodeLDRPreImm(llvm::MCInst &Inst, unsigned Insn,
3061                             uint64_t Address, const void *Decoder) {
3062   DecodeStatus S = MCDisassembler::Success;
3063 
3064   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3065   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3066   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3067   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3068   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3069   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3070 
3071   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3072 
3073   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3074     return MCDisassembler::Fail;
3075   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3076     return MCDisassembler::Fail;
3077   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, 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 DecodeLDRPreReg(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   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3096 
3097   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3098   if (Rm == 0xF) S = MCDisassembler::SoftFail;
3099 
3100   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3101     return MCDisassembler::Fail;
3102   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3103     return MCDisassembler::Fail;
3104   if (!Check(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder)))
3105     return MCDisassembler::Fail;
3106   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3107     return MCDisassembler::Fail;
3108 
3109   return S;
3110 }
3111 
3112 
3113 static DecodeStatus DecodeSTRPreImm(llvm::MCInst &Inst, unsigned Insn,
3114                             uint64_t Address, const void *Decoder) {
3115   DecodeStatus S = MCDisassembler::Success;
3116 
3117   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3118   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3119   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
3120   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
3121   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
3122   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3123 
3124   if (Rn == 0xF || Rn == Rt) S = MCDisassembler::SoftFail;
3125 
3126   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3127     return MCDisassembler::Fail;
3128   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)))
3129     return MCDisassembler::Fail;
3130   if (!Check(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)))
3131     return MCDisassembler::Fail;
3132   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3133     return MCDisassembler::Fail;
3134 
3135   return S;
3136 }
3137 
3138 static DecodeStatus DecodeSTRPreReg(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, DecodeSORegMemOperand(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 DecodeVLD1LN(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 Rm = fieldFromInstruction32(Insn, 0, 4);
3169   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3170   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3171   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3172 
3173   unsigned align = 0;
3174   unsigned index = 0;
3175   switch (size) {
3176     default:
3177       return MCDisassembler::Fail;
3178     case 0:
3179       if (fieldFromInstruction32(Insn, 4, 1))
3180         return MCDisassembler::Fail; // UNDEFINED
3181       index = fieldFromInstruction32(Insn, 5, 3);
3182       break;
3183     case 1:
3184       if (fieldFromInstruction32(Insn, 5, 1))
3185         return MCDisassembler::Fail; // UNDEFINED
3186       index = fieldFromInstruction32(Insn, 6, 2);
3187       if (fieldFromInstruction32(Insn, 4, 1))
3188         align = 2;
3189       break;
3190     case 2:
3191       if (fieldFromInstruction32(Insn, 6, 1))
3192         return MCDisassembler::Fail; // UNDEFINED
3193       index = fieldFromInstruction32(Insn, 7, 1);
3194       if (fieldFromInstruction32(Insn, 4, 2) != 0)
3195         align = 4;
3196   }
3197 
3198   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3199     return MCDisassembler::Fail;
3200   if (Rm != 0xF) { // Writeback
3201     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3202       return MCDisassembler::Fail;
3203   }
3204   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3205     return MCDisassembler::Fail;
3206   Inst.addOperand(MCOperand::CreateImm(align));
3207   if (Rm != 0xF) {
3208     if (Rm != 0xD) {
3209       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3210         return MCDisassembler::Fail;
3211     } else
3212       Inst.addOperand(MCOperand::CreateReg(0));
3213   }
3214 
3215   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3216     return MCDisassembler::Fail;
3217   Inst.addOperand(MCOperand::CreateImm(index));
3218 
3219   return S;
3220 }
3221 
3222 static DecodeStatus DecodeVST1LN(llvm::MCInst &Inst, unsigned Insn,
3223                          uint64_t Address, const void *Decoder) {
3224   DecodeStatus S = MCDisassembler::Success;
3225 
3226   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3227   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3228   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3229   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3230   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3231 
3232   unsigned align = 0;
3233   unsigned index = 0;
3234   switch (size) {
3235     default:
3236       return MCDisassembler::Fail;
3237     case 0:
3238       if (fieldFromInstruction32(Insn, 4, 1))
3239         return MCDisassembler::Fail; // UNDEFINED
3240       index = fieldFromInstruction32(Insn, 5, 3);
3241       break;
3242     case 1:
3243       if (fieldFromInstruction32(Insn, 5, 1))
3244         return MCDisassembler::Fail; // UNDEFINED
3245       index = fieldFromInstruction32(Insn, 6, 2);
3246       if (fieldFromInstruction32(Insn, 4, 1))
3247         align = 2;
3248       break;
3249     case 2:
3250       if (fieldFromInstruction32(Insn, 6, 1))
3251         return MCDisassembler::Fail; // UNDEFINED
3252       index = fieldFromInstruction32(Insn, 7, 1);
3253       if (fieldFromInstruction32(Insn, 4, 2) != 0)
3254         align = 4;
3255   }
3256 
3257   if (Rm != 0xF) { // Writeback
3258     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3259     return MCDisassembler::Fail;
3260   }
3261   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3262     return MCDisassembler::Fail;
3263   Inst.addOperand(MCOperand::CreateImm(align));
3264   if (Rm != 0xF) {
3265     if (Rm != 0xD) {
3266       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3267     return MCDisassembler::Fail;
3268     } else
3269       Inst.addOperand(MCOperand::CreateReg(0));
3270   }
3271 
3272   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3273     return MCDisassembler::Fail;
3274   Inst.addOperand(MCOperand::CreateImm(index));
3275 
3276   return S;
3277 }
3278 
3279 
3280 static DecodeStatus DecodeVLD2LN(llvm::MCInst &Inst, unsigned Insn,
3281                          uint64_t Address, const void *Decoder) {
3282   DecodeStatus S = MCDisassembler::Success;
3283 
3284   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3285   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3286   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3287   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3288   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3289 
3290   unsigned align = 0;
3291   unsigned index = 0;
3292   unsigned inc = 1;
3293   switch (size) {
3294     default:
3295       return MCDisassembler::Fail;
3296     case 0:
3297       index = fieldFromInstruction32(Insn, 5, 3);
3298       if (fieldFromInstruction32(Insn, 4, 1))
3299         align = 2;
3300       break;
3301     case 1:
3302       index = fieldFromInstruction32(Insn, 6, 2);
3303       if (fieldFromInstruction32(Insn, 4, 1))
3304         align = 4;
3305       if (fieldFromInstruction32(Insn, 5, 1))
3306         inc = 2;
3307       break;
3308     case 2:
3309       if (fieldFromInstruction32(Insn, 5, 1))
3310         return MCDisassembler::Fail; // UNDEFINED
3311       index = fieldFromInstruction32(Insn, 7, 1);
3312       if (fieldFromInstruction32(Insn, 4, 1) != 0)
3313         align = 8;
3314       if (fieldFromInstruction32(Insn, 6, 1))
3315         inc = 2;
3316       break;
3317   }
3318 
3319   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3320     return MCDisassembler::Fail;
3321   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3322     return MCDisassembler::Fail;
3323   if (Rm != 0xF) { // Writeback
3324     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3325       return MCDisassembler::Fail;
3326   }
3327   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3328     return MCDisassembler::Fail;
3329   Inst.addOperand(MCOperand::CreateImm(align));
3330   if (Rm != 0xF) {
3331     if (Rm != 0xD) {
3332       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3333         return MCDisassembler::Fail;
3334     } else
3335       Inst.addOperand(MCOperand::CreateReg(0));
3336   }
3337 
3338   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3339     return MCDisassembler::Fail;
3340   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3341     return MCDisassembler::Fail;
3342   Inst.addOperand(MCOperand::CreateImm(index));
3343 
3344   return S;
3345 }
3346 
3347 static DecodeStatus DecodeVST2LN(llvm::MCInst &Inst, unsigned Insn,
3348                          uint64_t Address, const void *Decoder) {
3349   DecodeStatus S = MCDisassembler::Success;
3350 
3351   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3352   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3353   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3354   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3355   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3356 
3357   unsigned align = 0;
3358   unsigned index = 0;
3359   unsigned inc = 1;
3360   switch (size) {
3361     default:
3362       return MCDisassembler::Fail;
3363     case 0:
3364       index = fieldFromInstruction32(Insn, 5, 3);
3365       if (fieldFromInstruction32(Insn, 4, 1))
3366         align = 2;
3367       break;
3368     case 1:
3369       index = fieldFromInstruction32(Insn, 6, 2);
3370       if (fieldFromInstruction32(Insn, 4, 1))
3371         align = 4;
3372       if (fieldFromInstruction32(Insn, 5, 1))
3373         inc = 2;
3374       break;
3375     case 2:
3376       if (fieldFromInstruction32(Insn, 5, 1))
3377         return MCDisassembler::Fail; // UNDEFINED
3378       index = fieldFromInstruction32(Insn, 7, 1);
3379       if (fieldFromInstruction32(Insn, 4, 1) != 0)
3380         align = 8;
3381       if (fieldFromInstruction32(Insn, 6, 1))
3382         inc = 2;
3383       break;
3384   }
3385 
3386   if (Rm != 0xF) { // Writeback
3387     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3388       return MCDisassembler::Fail;
3389   }
3390   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3391     return MCDisassembler::Fail;
3392   Inst.addOperand(MCOperand::CreateImm(align));
3393   if (Rm != 0xF) {
3394     if (Rm != 0xD) {
3395       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3396         return MCDisassembler::Fail;
3397     } else
3398       Inst.addOperand(MCOperand::CreateReg(0));
3399   }
3400 
3401   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3402     return MCDisassembler::Fail;
3403   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3404     return MCDisassembler::Fail;
3405   Inst.addOperand(MCOperand::CreateImm(index));
3406 
3407   return S;
3408 }
3409 
3410 
3411 static DecodeStatus DecodeVLD3LN(llvm::MCInst &Inst, unsigned Insn,
3412                          uint64_t Address, const void *Decoder) {
3413   DecodeStatus S = MCDisassembler::Success;
3414 
3415   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3416   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3417   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3418   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3419   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3420 
3421   unsigned align = 0;
3422   unsigned index = 0;
3423   unsigned inc = 1;
3424   switch (size) {
3425     default:
3426       return MCDisassembler::Fail;
3427     case 0:
3428       if (fieldFromInstruction32(Insn, 4, 1))
3429         return MCDisassembler::Fail; // UNDEFINED
3430       index = fieldFromInstruction32(Insn, 5, 3);
3431       break;
3432     case 1:
3433       if (fieldFromInstruction32(Insn, 4, 1))
3434         return MCDisassembler::Fail; // UNDEFINED
3435       index = fieldFromInstruction32(Insn, 6, 2);
3436       if (fieldFromInstruction32(Insn, 5, 1))
3437         inc = 2;
3438       break;
3439     case 2:
3440       if (fieldFromInstruction32(Insn, 4, 2))
3441         return MCDisassembler::Fail; // UNDEFINED
3442       index = fieldFromInstruction32(Insn, 7, 1);
3443       if (fieldFromInstruction32(Insn, 6, 1))
3444         inc = 2;
3445       break;
3446   }
3447 
3448   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3449     return MCDisassembler::Fail;
3450   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3451     return MCDisassembler::Fail;
3452   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3453     return MCDisassembler::Fail;
3454 
3455   if (Rm != 0xF) { // Writeback
3456     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3457     return MCDisassembler::Fail;
3458   }
3459   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3460     return MCDisassembler::Fail;
3461   Inst.addOperand(MCOperand::CreateImm(align));
3462   if (Rm != 0xF) {
3463     if (Rm != 0xD) {
3464       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3465     return MCDisassembler::Fail;
3466     } else
3467       Inst.addOperand(MCOperand::CreateReg(0));
3468   }
3469 
3470   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3471     return MCDisassembler::Fail;
3472   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3473     return MCDisassembler::Fail;
3474   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3475     return MCDisassembler::Fail;
3476   Inst.addOperand(MCOperand::CreateImm(index));
3477 
3478   return S;
3479 }
3480 
3481 static DecodeStatus DecodeVST3LN(llvm::MCInst &Inst, unsigned Insn,
3482                          uint64_t Address, const void *Decoder) {
3483   DecodeStatus S = MCDisassembler::Success;
3484 
3485   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3486   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3487   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3488   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3489   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3490 
3491   unsigned align = 0;
3492   unsigned index = 0;
3493   unsigned inc = 1;
3494   switch (size) {
3495     default:
3496       return MCDisassembler::Fail;
3497     case 0:
3498       if (fieldFromInstruction32(Insn, 4, 1))
3499         return MCDisassembler::Fail; // UNDEFINED
3500       index = fieldFromInstruction32(Insn, 5, 3);
3501       break;
3502     case 1:
3503       if (fieldFromInstruction32(Insn, 4, 1))
3504         return MCDisassembler::Fail; // UNDEFINED
3505       index = fieldFromInstruction32(Insn, 6, 2);
3506       if (fieldFromInstruction32(Insn, 5, 1))
3507         inc = 2;
3508       break;
3509     case 2:
3510       if (fieldFromInstruction32(Insn, 4, 2))
3511         return MCDisassembler::Fail; // UNDEFINED
3512       index = fieldFromInstruction32(Insn, 7, 1);
3513       if (fieldFromInstruction32(Insn, 6, 1))
3514         inc = 2;
3515       break;
3516   }
3517 
3518   if (Rm != 0xF) { // Writeback
3519     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3520     return MCDisassembler::Fail;
3521   }
3522   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3523     return MCDisassembler::Fail;
3524   Inst.addOperand(MCOperand::CreateImm(align));
3525   if (Rm != 0xF) {
3526     if (Rm != 0xD) {
3527       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3528     return MCDisassembler::Fail;
3529     } else
3530       Inst.addOperand(MCOperand::CreateReg(0));
3531   }
3532 
3533   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3534     return MCDisassembler::Fail;
3535   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3536     return MCDisassembler::Fail;
3537   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3538     return MCDisassembler::Fail;
3539   Inst.addOperand(MCOperand::CreateImm(index));
3540 
3541   return S;
3542 }
3543 
3544 
3545 static DecodeStatus DecodeVLD4LN(llvm::MCInst &Inst, unsigned Insn,
3546                          uint64_t Address, const void *Decoder) {
3547   DecodeStatus S = MCDisassembler::Success;
3548 
3549   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3550   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3551   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3552   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3553   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3554 
3555   unsigned align = 0;
3556   unsigned index = 0;
3557   unsigned inc = 1;
3558   switch (size) {
3559     default:
3560       return MCDisassembler::Fail;
3561     case 0:
3562       if (fieldFromInstruction32(Insn, 4, 1))
3563         align = 4;
3564       index = fieldFromInstruction32(Insn, 5, 3);
3565       break;
3566     case 1:
3567       if (fieldFromInstruction32(Insn, 4, 1))
3568         align = 8;
3569       index = fieldFromInstruction32(Insn, 6, 2);
3570       if (fieldFromInstruction32(Insn, 5, 1))
3571         inc = 2;
3572       break;
3573     case 2:
3574       if (fieldFromInstruction32(Insn, 4, 2))
3575         align = 4 << fieldFromInstruction32(Insn, 4, 2);
3576       index = fieldFromInstruction32(Insn, 7, 1);
3577       if (fieldFromInstruction32(Insn, 6, 1))
3578         inc = 2;
3579       break;
3580   }
3581 
3582   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3583     return MCDisassembler::Fail;
3584   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3585     return MCDisassembler::Fail;
3586   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3587     return MCDisassembler::Fail;
3588   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
3589     return MCDisassembler::Fail;
3590 
3591   if (Rm != 0xF) { // Writeback
3592     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3593       return MCDisassembler::Fail;
3594   }
3595   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3596     return MCDisassembler::Fail;
3597   Inst.addOperand(MCOperand::CreateImm(align));
3598   if (Rm != 0xF) {
3599     if (Rm != 0xD) {
3600       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3601         return MCDisassembler::Fail;
3602     } else
3603       Inst.addOperand(MCOperand::CreateReg(0));
3604   }
3605 
3606   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3607     return MCDisassembler::Fail;
3608   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3609     return MCDisassembler::Fail;
3610   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3611     return MCDisassembler::Fail;
3612   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
3613     return MCDisassembler::Fail;
3614   Inst.addOperand(MCOperand::CreateImm(index));
3615 
3616   return S;
3617 }
3618 
3619 static DecodeStatus DecodeVST4LN(llvm::MCInst &Inst, unsigned Insn,
3620                          uint64_t Address, const void *Decoder) {
3621   DecodeStatus S = MCDisassembler::Success;
3622 
3623   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3624   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3625   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3626   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3627   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3628 
3629   unsigned align = 0;
3630   unsigned index = 0;
3631   unsigned inc = 1;
3632   switch (size) {
3633     default:
3634       return MCDisassembler::Fail;
3635     case 0:
3636       if (fieldFromInstruction32(Insn, 4, 1))
3637         align = 4;
3638       index = fieldFromInstruction32(Insn, 5, 3);
3639       break;
3640     case 1:
3641       if (fieldFromInstruction32(Insn, 4, 1))
3642         align = 8;
3643       index = fieldFromInstruction32(Insn, 6, 2);
3644       if (fieldFromInstruction32(Insn, 5, 1))
3645         inc = 2;
3646       break;
3647     case 2:
3648       if (fieldFromInstruction32(Insn, 4, 2))
3649         align = 4 << fieldFromInstruction32(Insn, 4, 2);
3650       index = fieldFromInstruction32(Insn, 7, 1);
3651       if (fieldFromInstruction32(Insn, 6, 1))
3652         inc = 2;
3653       break;
3654   }
3655 
3656   if (Rm != 0xF) { // Writeback
3657     if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3658     return MCDisassembler::Fail;
3659   }
3660   if (!Check(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)))
3661     return MCDisassembler::Fail;
3662   Inst.addOperand(MCOperand::CreateImm(align));
3663   if (Rm != 0xF) {
3664     if (Rm != 0xD) {
3665       if (!Check(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)))
3666     return MCDisassembler::Fail;
3667     } else
3668       Inst.addOperand(MCOperand::CreateReg(0));
3669   }
3670 
3671   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)))
3672     return MCDisassembler::Fail;
3673   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder)))
3674     return MCDisassembler::Fail;
3675   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder)))
3676     return MCDisassembler::Fail;
3677   if (!Check(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder)))
3678     return MCDisassembler::Fail;
3679   Inst.addOperand(MCOperand::CreateImm(index));
3680 
3681   return S;
3682 }
3683 
3684 static DecodeStatus DecodeVMOVSRR(llvm::MCInst &Inst, unsigned Insn,
3685                                   uint64_t Address, const void *Decoder) {
3686   DecodeStatus S = MCDisassembler::Success;
3687   unsigned Rt  = fieldFromInstruction32(Insn, 12, 4);
3688   unsigned Rt2 = fieldFromInstruction32(Insn, 16, 4);
3689   unsigned Rm  = fieldFromInstruction32(Insn,  0, 4);
3690   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3691   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
3692 
3693   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
3694     S = MCDisassembler::SoftFail;
3695 
3696   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
3697     return MCDisassembler::Fail;
3698   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
3699     return MCDisassembler::Fail;
3700   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
3701     return MCDisassembler::Fail;
3702   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
3703     return MCDisassembler::Fail;
3704   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3705     return MCDisassembler::Fail;
3706 
3707   return S;
3708 }
3709 
3710 static DecodeStatus DecodeVMOVRRS(llvm::MCInst &Inst, unsigned Insn,
3711                                   uint64_t Address, const void *Decoder) {
3712   DecodeStatus S = MCDisassembler::Success;
3713   unsigned Rt  = fieldFromInstruction32(Insn, 12, 4);
3714   unsigned Rt2 = fieldFromInstruction32(Insn, 16, 4);
3715   unsigned Rm  = fieldFromInstruction32(Insn,  0, 4);
3716   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
3717   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
3718 
3719   if (Rt == 0xF || Rt2 == 0xF || Rm == 0x1F)
3720     S = MCDisassembler::SoftFail;
3721 
3722   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt  , Address, Decoder)))
3723     return MCDisassembler::Fail;
3724   if (!Check(S, DecodeGPRRegisterClass(Inst, Rt2 , Address, Decoder)))
3725     return MCDisassembler::Fail;
3726   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm  , Address, Decoder)))
3727     return MCDisassembler::Fail;
3728   if (!Check(S, DecodeSPRRegisterClass(Inst, Rm+1, Address, Decoder)))
3729     return MCDisassembler::Fail;
3730   if (!Check(S, DecodePredicateOperand(Inst, pred, Address, Decoder)))
3731     return MCDisassembler::Fail;
3732 
3733   return S;
3734 }
3735 
3736 static DecodeStatus DecodeIT(llvm::MCInst &Inst, unsigned Insn,
3737                              uint64_t Address, const void *Decoder) {
3738   DecodeStatus S = MCDisassembler::Success;
3739   unsigned pred = fieldFromInstruction16(Insn, 4, 4);
3740   // The InstPrinter needs to have the low bit of the predicate in
3741   // the mask operand to be able to print it properly.
3742   unsigned mask = fieldFromInstruction16(Insn, 0, 5);
3743 
3744   if (pred == 0xF) {
3745     pred = 0xE;
3746     S = MCDisassembler::SoftFail;
3747   }
3748 
3749   if ((mask & 0xF) == 0) {
3750     // Preserve the high bit of the mask, which is the low bit of
3751     // the predicate.
3752     mask &= 0x10;
3753     mask |= 0x8;
3754     S = MCDisassembler::SoftFail;
3755   }
3756 
3757   Inst.addOperand(MCOperand::CreateImm(pred));
3758   Inst.addOperand(MCOperand::CreateImm(mask));
3759   return S;
3760 }
3761 
3762 static DecodeStatus
3763 DecodeT2LDRDPreInstruction(llvm::MCInst &Inst, unsigned Insn,
3764                            uint64_t Address, const void *Decoder) {
3765   DecodeStatus S = MCDisassembler::Success;
3766 
3767   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3768   unsigned Rt2 = fieldFromInstruction32(Insn, 8, 4);
3769   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3770   unsigned addr = fieldFromInstruction32(Insn, 0, 8);
3771   unsigned W = fieldFromInstruction32(Insn, 21, 1);
3772   unsigned U = fieldFromInstruction32(Insn, 23, 1);
3773   unsigned P = fieldFromInstruction32(Insn, 24, 1);
3774   bool writeback = (W == 1) | (P == 0);
3775 
3776   addr |= (U << 8) | (Rn << 9);
3777 
3778   if (writeback && (Rn == Rt || Rn == Rt2))
3779     Check(S, MCDisassembler::SoftFail);
3780   if (Rt == Rt2)
3781     Check(S, MCDisassembler::SoftFail);
3782 
3783   // Rt
3784   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
3785     return MCDisassembler::Fail;
3786   // Rt2
3787   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
3788     return MCDisassembler::Fail;
3789   // Writeback operand
3790   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
3791     return MCDisassembler::Fail;
3792   // addr
3793   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
3794     return MCDisassembler::Fail;
3795 
3796   return S;
3797 }
3798 
3799 static DecodeStatus
3800 DecodeT2STRDPreInstruction(llvm::MCInst &Inst, unsigned Insn,
3801                            uint64_t Address, const void *Decoder) {
3802   DecodeStatus S = MCDisassembler::Success;
3803 
3804   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
3805   unsigned Rt2 = fieldFromInstruction32(Insn, 8, 4);
3806   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3807   unsigned addr = fieldFromInstruction32(Insn, 0, 8);
3808   unsigned W = fieldFromInstruction32(Insn, 21, 1);
3809   unsigned U = fieldFromInstruction32(Insn, 23, 1);
3810   unsigned P = fieldFromInstruction32(Insn, 24, 1);
3811   bool writeback = (W == 1) | (P == 0);
3812 
3813   addr |= (U << 8) | (Rn << 9);
3814 
3815   if (writeback && (Rn == Rt || Rn == Rt2))
3816     Check(S, MCDisassembler::SoftFail);
3817 
3818   // Writeback operand
3819   if (!Check(S, DecoderGPRRegisterClass(Inst, Rn, Address, Decoder)))
3820     return MCDisassembler::Fail;
3821   // Rt
3822   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt, Address, Decoder)))
3823     return MCDisassembler::Fail;
3824   // Rt2
3825   if (!Check(S, DecoderGPRRegisterClass(Inst, Rt2, Address, Decoder)))
3826     return MCDisassembler::Fail;
3827   // addr
3828   if (!Check(S, DecodeT2AddrModeImm8s4(Inst, addr, Address, Decoder)))
3829     return MCDisassembler::Fail;
3830 
3831   return S;
3832 }
3833 
3834 static DecodeStatus DecodeT2Adr(llvm::MCInst &Inst, uint32_t Insn,
3835                                 uint64_t Address, const void *Decoder) {
3836   unsigned sign1 = fieldFromInstruction32(Insn, 21, 1);
3837   unsigned sign2 = fieldFromInstruction32(Insn, 23, 1);
3838   if (sign1 != sign2) return MCDisassembler::Fail;
3839 
3840   unsigned Val = fieldFromInstruction32(Insn, 0, 8);
3841   Val |= fieldFromInstruction32(Insn, 12, 3) << 8;
3842   Val |= fieldFromInstruction32(Insn, 26, 1) << 11;
3843   Val |= sign1 << 12;
3844   Inst.addOperand(MCOperand::CreateImm(SignExtend32<13>(Val)));
3845 
3846   return MCDisassembler::Success;
3847 }
3848 
3849