xref: /llvm-project/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (revision 67d6f119740da076b5232d17cbe9ece8b8eae1bc)
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 "ARMDisassembler.h"
13 #include "ARM.h"
14 #include "ARMRegisterInfo.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/Target/TargetRegistry.h"
22 #include "llvm/Support/Debug.h"
23 #include "llvm/Support/MemoryObject.h"
24 #include "llvm/Support/ErrorHandling.h"
25 #include "llvm/Support/raw_ostream.h"
26 
27 // Pull DecodeStatus and its enum values into the global namespace.
28 typedef llvm::MCDisassembler::DecodeStatus DecodeStatus;
29 #define Success llvm::MCDisassembler::Success
30 #define Unpredictable llvm::MCDisassembler::SoftFail
31 #define Fail llvm::MCDisassembler::Fail
32 
33 // Helper macro to perform setwise reduction of the current running status
34 // and another status, and return if the new status is Fail.
35 #define CHECK(S,X) do {                           \
36     S = (DecodeStatus) ((int)S & (X));            \
37     if (S == Fail) return Fail;                   \
38   } while(0)
39 
40 // Forward declare these because the autogenerated code will reference them.
41 // Definitions are further down.
42 static DecodeStatus DecodeGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
43                                    uint64_t Address, const void *Decoder);
44 static DecodeStatus DecodeGPRnopcRegisterClass(llvm::MCInst &Inst,
45                                                unsigned RegNo, uint64_t Address,
46                                                const void *Decoder);
47 static DecodeStatus DecodetGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
48                                    uint64_t Address, const void *Decoder);
49 static DecodeStatus DecodetcGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
50                                    uint64_t Address, const void *Decoder);
51 static DecodeStatus DecoderGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
52                                    uint64_t Address, const void *Decoder);
53 static DecodeStatus DecodeSPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
54                                    uint64_t Address, const void *Decoder);
55 static DecodeStatus DecodeDPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
56                                    uint64_t Address, const void *Decoder);
57 static DecodeStatus DecodeDPR_8RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
58                                    uint64_t Address, const void *Decoder);
59 static DecodeStatus DecodeDPR_VFP2RegisterClass(llvm::MCInst &Inst,
60                                                 unsigned RegNo,
61                                                 uint64_t Address,
62                                                 const void *Decoder);
63 static DecodeStatus DecodeQPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
64                                    uint64_t Address, const void *Decoder);
65 
66 static DecodeStatus DecodePredicateOperand(llvm::MCInst &Inst, unsigned Val,
67                                uint64_t Address, const void *Decoder);
68 static DecodeStatus DecodeCCOutOperand(llvm::MCInst &Inst, unsigned Val,
69                                uint64_t Address, const void *Decoder);
70 static DecodeStatus DecodeSOImmOperand(llvm::MCInst &Inst, unsigned Val,
71                                uint64_t Address, const void *Decoder);
72 static DecodeStatus DecodeBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
73                                uint64_t Address, const void *Decoder);
74 static DecodeStatus DecodeRegListOperand(llvm::MCInst &Inst, unsigned Val,
75                                uint64_t Address, const void *Decoder);
76 static DecodeStatus DecodeSPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
77                                uint64_t Address, const void *Decoder);
78 static DecodeStatus DecodeDPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
79                                uint64_t Address, const void *Decoder);
80 
81 static DecodeStatus DecodeBitfieldMaskOperand(llvm::MCInst &Inst, unsigned Insn,
82                                uint64_t Address, const void *Decoder);
83 static DecodeStatus DecodeCopMemInstruction(llvm::MCInst &Inst, unsigned Insn,
84                                uint64_t Address, const void *Decoder);
85 static DecodeStatus DecodeAddrMode2IdxInstruction(llvm::MCInst &Inst,
86                                                   unsigned Insn,
87                                                   uint64_t Address,
88                                                   const void *Decoder);
89 static DecodeStatus DecodeSORegMemOperand(llvm::MCInst &Inst, unsigned Insn,
90                                uint64_t Address, const void *Decoder);
91 static DecodeStatus DecodeAddrMode3Instruction(llvm::MCInst &Inst,unsigned Insn,
92                                uint64_t Address, const void *Decoder);
93 static DecodeStatus DecodeSORegImmOperand(llvm::MCInst &Inst, unsigned Insn,
94                                uint64_t Address, const void *Decoder);
95 static DecodeStatus DecodeSORegRegOperand(llvm::MCInst &Inst, unsigned Insn,
96                                uint64_t Address, const void *Decoder);
97 
98 static DecodeStatus DecodeMemMultipleWritebackInstruction(llvm::MCInst & Inst,
99                                                   unsigned Insn,
100                                                   uint64_t Adddress,
101                                                   const void *Decoder);
102 static DecodeStatus DecodeSMLAInstruction(llvm::MCInst &Inst, unsigned Insn,
103                                uint64_t Address, const void *Decoder);
104 static DecodeStatus DecodeCPSInstruction(llvm::MCInst &Inst, unsigned Insn,
105                                uint64_t Address, const void *Decoder);
106 static DecodeStatus DecodeAddrModeImm12Operand(llvm::MCInst &Inst, unsigned Val,
107                                uint64_t Address, const void *Decoder);
108 static DecodeStatus DecodeAddrMode5Operand(llvm::MCInst &Inst, unsigned Val,
109                                uint64_t Address, const void *Decoder);
110 static DecodeStatus DecodeAddrMode7Operand(llvm::MCInst &Inst, unsigned Val,
111                                uint64_t Address, const void *Decoder);
112 static DecodeStatus DecodeBranchImmInstruction(llvm::MCInst &Inst,unsigned Insn,
113                                uint64_t Address, const void *Decoder);
114 static DecodeStatus DecodeVCVTImmOperand(llvm::MCInst &Inst, unsigned Val,
115                                uint64_t Address, const void *Decoder);
116 static DecodeStatus DecodeAddrMode6Operand(llvm::MCInst &Inst, unsigned Val,
117                                uint64_t Address, const void *Decoder);
118 static DecodeStatus DecodeVLDInstruction(llvm::MCInst &Inst, unsigned Val,
119                                uint64_t Address, const void *Decoder);
120 static DecodeStatus DecodeVSTInstruction(llvm::MCInst &Inst, unsigned Val,
121                                uint64_t Address, const void *Decoder);
122 static DecodeStatus DecodeVLD1DupInstruction(llvm::MCInst &Inst, unsigned Val,
123                                uint64_t Address, const void *Decoder);
124 static DecodeStatus DecodeVLD2DupInstruction(llvm::MCInst &Inst, unsigned Val,
125                                uint64_t Address, const void *Decoder);
126 static DecodeStatus DecodeVLD3DupInstruction(llvm::MCInst &Inst, unsigned Val,
127                                uint64_t Address, const void *Decoder);
128 static DecodeStatus DecodeVLD4DupInstruction(llvm::MCInst &Inst, unsigned Val,
129                                uint64_t Address, const void *Decoder);
130 static DecodeStatus DecodeNEONModImmInstruction(llvm::MCInst &Inst,unsigned Val,
131                                uint64_t Address, const void *Decoder);
132 static DecodeStatus DecodeVSHLMaxInstruction(llvm::MCInst &Inst, unsigned Val,
133                                uint64_t Address, const void *Decoder);
134 static DecodeStatus DecodeShiftRight8Imm(llvm::MCInst &Inst, unsigned Val,
135                                uint64_t Address, const void *Decoder);
136 static DecodeStatus DecodeShiftRight16Imm(llvm::MCInst &Inst, unsigned Val,
137                                uint64_t Address, const void *Decoder);
138 static DecodeStatus DecodeShiftRight32Imm(llvm::MCInst &Inst, unsigned Val,
139                                uint64_t Address, const void *Decoder);
140 static DecodeStatus DecodeShiftRight64Imm(llvm::MCInst &Inst, unsigned Val,
141                                uint64_t Address, const void *Decoder);
142 static DecodeStatus DecodeTBLInstruction(llvm::MCInst &Inst, unsigned Insn,
143                                uint64_t Address, const void *Decoder);
144 static DecodeStatus DecodeVFPfpImm(llvm::MCInst &Inst, unsigned Val,
145                                uint64_t Address, const void *Decoder);
146 static DecodeStatus DecodePostIdxReg(llvm::MCInst &Inst, unsigned Insn,
147                                uint64_t Address, const void *Decoder);
148 static DecodeStatus DecodeCoprocessor(llvm::MCInst &Inst, unsigned Insn,
149                                uint64_t Address, const void *Decoder);
150 static DecodeStatus DecodeMemBarrierOption(llvm::MCInst &Inst, unsigned Insn,
151                                uint64_t Address, const void *Decoder);
152 static DecodeStatus DecodeMSRMask(llvm::MCInst &Inst, unsigned Insn,
153                                uint64_t Address, const void *Decoder);
154 static DecodeStatus DecodeDoubleRegLoad(llvm::MCInst &Inst, unsigned Insn,
155                                uint64_t Address, const void *Decoder);
156 static DecodeStatus DecodeDoubleRegStore(llvm::MCInst &Inst, unsigned Insn,
157                                uint64_t Address, const void *Decoder);
158 static DecodeStatus DecodeSTRPreImm(llvm::MCInst &Inst, unsigned Insn,
159                                uint64_t Address, const void *Decoder);
160 static DecodeStatus DecodeSTRPreReg(llvm::MCInst &Inst, unsigned Insn,
161                                uint64_t Address, const void *Decoder);
162 static DecodeStatus DecodeVLD1LN(llvm::MCInst &Inst, unsigned Insn,
163                                uint64_t Address, const void *Decoder);
164 static DecodeStatus DecodeVLD2LN(llvm::MCInst &Inst, unsigned Insn,
165                                uint64_t Address, const void *Decoder);
166 static DecodeStatus DecodeVLD3LN(llvm::MCInst &Inst, unsigned Insn,
167                                uint64_t Address, const void *Decoder);
168 static DecodeStatus DecodeVLD4LN(llvm::MCInst &Inst, unsigned Insn,
169                                uint64_t Address, const void *Decoder);
170 static DecodeStatus DecodeVST1LN(llvm::MCInst &Inst, unsigned Insn,
171                                uint64_t Address, const void *Decoder);
172 static DecodeStatus DecodeVST2LN(llvm::MCInst &Inst, unsigned Insn,
173                                uint64_t Address, const void *Decoder);
174 static DecodeStatus DecodeVST3LN(llvm::MCInst &Inst, unsigned Insn,
175                                uint64_t Address, const void *Decoder);
176 static DecodeStatus DecodeVST4LN(llvm::MCInst &Inst, unsigned Insn,
177                                uint64_t Address, const void *Decoder);
178 
179 
180 static DecodeStatus DecodeThumbAddSpecialReg(llvm::MCInst &Inst, uint16_t Insn,
181                                uint64_t Address, const void *Decoder);
182 static DecodeStatus DecodeThumbBROperand(llvm::MCInst &Inst, unsigned Val,
183                                uint64_t Address, const void *Decoder);
184 static DecodeStatus DecodeT2BROperand(llvm::MCInst &Inst, unsigned Val,
185                                uint64_t Address, const void *Decoder);
186 static DecodeStatus DecodeThumbCmpBROperand(llvm::MCInst &Inst, unsigned Val,
187                                uint64_t Address, const void *Decoder);
188 static DecodeStatus DecodeThumbAddrModeRR(llvm::MCInst &Inst, unsigned Val,
189                                uint64_t Address, const void *Decoder);
190 static DecodeStatus DecodeThumbAddrModeIS(llvm::MCInst &Inst, unsigned Val,
191                                uint64_t Address, const void *Decoder);
192 static DecodeStatus DecodeThumbAddrModePC(llvm::MCInst &Inst, unsigned Val,
193                                uint64_t Address, const void *Decoder);
194 static DecodeStatus DecodeThumbAddrModeSP(llvm::MCInst &Inst, unsigned Val,
195                                uint64_t Address, const void *Decoder);
196 static DecodeStatus DecodeT2AddrModeSOReg(llvm::MCInst &Inst, unsigned Val,
197                                uint64_t Address, const void *Decoder);
198 static DecodeStatus DecodeT2LoadShift(llvm::MCInst &Inst, unsigned Val,
199                                uint64_t Address, const void *Decoder);
200 static DecodeStatus DecodeT2Imm8S4(llvm::MCInst &Inst, unsigned Val,
201                                uint64_t Address, const void *Decoder);
202 static DecodeStatus DecodeT2AddrModeImm8s4(llvm::MCInst &Inst, unsigned Val,
203                                uint64_t Address, const void *Decoder);
204 static DecodeStatus DecodeT2Imm8(llvm::MCInst &Inst, unsigned Val,
205                                uint64_t Address, const void *Decoder);
206 static DecodeStatus DecodeT2AddrModeImm8(llvm::MCInst &Inst, unsigned Val,
207                                uint64_t Address, const void *Decoder);
208 static DecodeStatus DecodeThumbAddSPImm(llvm::MCInst &Inst, uint16_t Val,
209                                uint64_t Address, const void *Decoder);
210 static DecodeStatus DecodeThumbAddSPReg(llvm::MCInst &Inst, uint16_t Insn,
211                                 uint64_t Address, const void *Decoder);
212 static DecodeStatus DecodeThumbCPS(llvm::MCInst &Inst, uint16_t Insn,
213                                 uint64_t Address, const void *Decoder);
214 static DecodeStatus DecodeThumbBLXOffset(llvm::MCInst &Inst, unsigned Insn,
215                                 uint64_t Address, const void *Decoder);
216 static DecodeStatus DecodeT2AddrModeImm12(llvm::MCInst &Inst, unsigned Val,
217                                 uint64_t Address, const void *Decoder);
218 static DecodeStatus DecodeThumb2BCCInstruction(llvm::MCInst &Inst, unsigned Val,
219                                 uint64_t Address, const void *Decoder);
220 static DecodeStatus DecodeT2SOImm(llvm::MCInst &Inst, unsigned Val,
221                                 uint64_t Address, const void *Decoder);
222 static DecodeStatus DecodeThumbBCCTargetOperand(llvm::MCInst &Inst,unsigned Val,
223                                 uint64_t Address, const void *Decoder);
224 static DecodeStatus DecodeThumbBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
225                                 uint64_t Address, const void *Decoder);
226 
227 #include "ARMGenDisassemblerTables.inc"
228 #include "ARMGenInstrInfo.inc"
229 #include "ARMGenEDInfo.inc"
230 
231 using namespace llvm;
232 
233 static MCDisassembler *createARMDisassembler(const Target &T) {
234   return new ARMDisassembler;
235 }
236 
237 static MCDisassembler *createThumbDisassembler(const Target &T) {
238   return new ThumbDisassembler;
239 }
240 
241 EDInstInfo *ARMDisassembler::getEDInfo() const {
242   return instInfoARM;
243 }
244 
245 EDInstInfo *ThumbDisassembler::getEDInfo() const {
246   return instInfoARM;
247 }
248 
249 DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
250                                              const MemoryObject &Region,
251                                              uint64_t Address,
252                                              raw_ostream &os) const {
253   uint8_t bytes[4];
254 
255   // We want to read exactly 4 bytes of data.
256   if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1)
257     return Fail;
258 
259   // Encoded as a small-endian 32-bit word in the stream.
260   uint32_t insn = (bytes[3] << 24) |
261                   (bytes[2] << 16) |
262                   (bytes[1] <<  8) |
263                   (bytes[0] <<  0);
264 
265   // Calling the auto-generated decoder function.
266   DecodeStatus result = decodeARMInstruction32(MI, insn, Address, this);
267   if (result != Fail) {
268     Size = 4;
269     return result;
270   }
271 
272   // Instructions that are shared between ARM and Thumb modes.
273   // FIXME: This shouldn't really exist.  It's an artifact of the
274   // fact that we fail to encode a few instructions properly for Thumb.
275   MI.clear();
276   result = decodeCommonInstruction32(MI, insn, Address, this);
277   if (result != Fail) {
278     Size = 4;
279     return result;
280   }
281 
282   // VFP and NEON instructions, similarly, are shared between ARM
283   // and Thumb modes.
284   MI.clear();
285   result = decodeVFPInstruction32(MI, insn, Address, this);
286   if (result != Fail) {
287     Size = 4;
288     return result;
289   }
290 
291   MI.clear();
292   result = decodeNEONDataInstruction32(MI, insn, Address, this);
293   if (result != Fail) {
294     Size = 4;
295     // Add a fake predicate operand, because we share these instruction
296     // definitions with Thumb2 where these instructions are predicable.
297     if (!DecodePredicateOperand(MI, 0xE, Address, this)) return Fail;
298     return result;
299   }
300 
301   MI.clear();
302   result = decodeNEONLoadStoreInstruction32(MI, insn, Address, this);
303   if (result != Fail) {
304     Size = 4;
305     // Add a fake predicate operand, because we share these instruction
306     // definitions with Thumb2 where these instructions are predicable.
307     if (!DecodePredicateOperand(MI, 0xE, Address, this)) return Fail;
308     return result;
309   }
310 
311   MI.clear();
312   result = decodeNEONDupInstruction32(MI, insn, Address, this);
313   if (result != Fail) {
314     Size = 4;
315     // Add a fake predicate operand, because we share these instruction
316     // definitions with Thumb2 where these instructions are predicable.
317     if (!DecodePredicateOperand(MI, 0xE, Address, this)) return Fail;
318     return result;
319   }
320 
321   MI.clear();
322 
323   return Fail;
324 }
325 
326 namespace llvm {
327 extern MCInstrDesc ARMInsts[];
328 }
329 
330 // Thumb1 instructions don't have explicit S bits.  Rather, they
331 // implicitly set CPSR.  Since it's not represented in the encoding, the
332 // auto-generated decoder won't inject the CPSR operand.  We need to fix
333 // that as a post-pass.
334 static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
335   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
336   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
337   MCInst::iterator I = MI.begin();
338   for (unsigned i = 0; i < NumOps; ++i, ++I) {
339     if (I == MI.end()) break;
340     if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
341       if (i > 0 && OpInfo[i-1].isPredicate()) continue;
342       MI.insert(I, MCOperand::CreateReg(InITBlock ? 0 : ARM::CPSR));
343       return;
344     }
345   }
346 
347   MI.insert(I, MCOperand::CreateReg(InITBlock ? 0 : ARM::CPSR));
348 }
349 
350 // Most Thumb instructions don't have explicit predicates in the
351 // encoding, but rather get their predicates from IT context.  We need
352 // to fix up the predicate operands using this context information as a
353 // post-pass.
354 void ThumbDisassembler::AddThumbPredicate(MCInst &MI) const {
355   // A few instructions actually have predicates encoded in them.  Don't
356   // try to overwrite it if we're seeing one of those.
357   switch (MI.getOpcode()) {
358     case ARM::tBcc:
359     case ARM::t2Bcc:
360       return;
361     default:
362       break;
363   }
364 
365   // If we're in an IT block, base the predicate on that.  Otherwise,
366   // assume a predicate of AL.
367   unsigned CC;
368   if (!ITBlock.empty()) {
369     CC = ITBlock.back();
370     ITBlock.pop_back();
371   } else
372     CC = ARMCC::AL;
373 
374   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
375   unsigned short NumOps = ARMInsts[MI.getOpcode()].NumOperands;
376   MCInst::iterator I = MI.begin();
377   for (unsigned i = 0; i < NumOps; ++i, ++I) {
378     if (I == MI.end()) break;
379     if (OpInfo[i].isPredicate()) {
380       I = MI.insert(I, MCOperand::CreateImm(CC));
381       ++I;
382       if (CC == ARMCC::AL)
383         MI.insert(I, MCOperand::CreateReg(0));
384       else
385         MI.insert(I, MCOperand::CreateReg(ARM::CPSR));
386       return;
387     }
388   }
389 
390   I = MI.insert(I, MCOperand::CreateImm(CC));
391   ++I;
392   if (CC == ARMCC::AL)
393     MI.insert(I, MCOperand::CreateReg(0));
394   else
395     MI.insert(I, MCOperand::CreateReg(ARM::CPSR));
396 }
397 
398 // Thumb VFP instructions are a special case.  Because we share their
399 // encodings between ARM and Thumb modes, and they are predicable in ARM
400 // mode, the auto-generated decoder will give them an (incorrect)
401 // predicate operand.  We need to rewrite these operands based on the IT
402 // context as a post-pass.
403 void ThumbDisassembler::UpdateThumbVFPPredicate(MCInst &MI) const {
404   unsigned CC;
405   if (!ITBlock.empty()) {
406     CC = ITBlock.back();
407     ITBlock.pop_back();
408   } else
409     CC = ARMCC::AL;
410 
411   const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
412   MCInst::iterator I = MI.begin();
413   for (unsigned i = 0, e = MI.size(); i < e; ++i, ++I) {
414     if (OpInfo[i].isPredicate() ) {
415       I->setImm(CC);
416       ++I;
417       if (CC == ARMCC::AL)
418         I->setReg(0);
419       else
420         I->setReg(ARM::CPSR);
421       return;
422     }
423   }
424 }
425 
426 DecodeStatus ThumbDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
427                                                const MemoryObject &Region,
428                                                uint64_t Address,
429                                                raw_ostream &os) const {
430   uint8_t bytes[4];
431 
432   // We want to read exactly 2 bytes of data.
433   if (Region.readBytes(Address, 2, (uint8_t*)bytes, NULL) == -1)
434     return Fail;
435 
436   uint16_t insn16 = (bytes[1] << 8) | bytes[0];
437   DecodeStatus result = decodeThumbInstruction16(MI, insn16, Address, this);
438   if (result != Fail) {
439     Size = 2;
440     AddThumbPredicate(MI);
441     return result;
442   }
443 
444   MI.clear();
445   result = decodeThumbSBitInstruction16(MI, insn16, Address, this);
446   if (result) {
447     Size = 2;
448     bool InITBlock = !ITBlock.empty();
449     AddThumbPredicate(MI);
450     AddThumb1SBit(MI, InITBlock);
451     return result;
452   }
453 
454   MI.clear();
455   result = decodeThumb2Instruction16(MI, insn16, Address, this);
456   if (result != Fail) {
457     Size = 2;
458     AddThumbPredicate(MI);
459 
460     // If we find an IT instruction, we need to parse its condition
461     // code and mask operands so that we can apply them correctly
462     // to the subsequent instructions.
463     if (MI.getOpcode() == ARM::t2IT) {
464       unsigned firstcond = MI.getOperand(0).getImm();
465       uint32_t mask = MI.getOperand(1).getImm();
466       unsigned zeros = CountTrailingZeros_32(mask);
467       mask >>= zeros+1;
468 
469       for (unsigned i = 0; i < 4 - (zeros+1); ++i) {
470         if (firstcond ^ (mask & 1))
471           ITBlock.push_back(firstcond ^ 1);
472         else
473           ITBlock.push_back(firstcond);
474         mask >>= 1;
475       }
476       ITBlock.push_back(firstcond);
477     }
478 
479     return result;
480   }
481 
482   // We want to read exactly 4 bytes of data.
483   if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1)
484     return Fail;
485 
486   uint32_t insn32 = (bytes[3] <<  8) |
487                     (bytes[2] <<  0) |
488                     (bytes[1] << 24) |
489                     (bytes[0] << 16);
490   MI.clear();
491   result = decodeThumbInstruction32(MI, insn32, Address, this);
492   if (result != Fail) {
493     Size = 4;
494     bool InITBlock = ITBlock.size();
495     AddThumbPredicate(MI);
496     AddThumb1SBit(MI, InITBlock);
497     return result;
498   }
499 
500   MI.clear();
501   result = decodeThumb2Instruction32(MI, insn32, Address, this);
502   if (result != Fail) {
503     Size = 4;
504     AddThumbPredicate(MI);
505     return result;
506   }
507 
508   MI.clear();
509   result = decodeCommonInstruction32(MI, insn32, Address, this);
510   if (result != Fail) {
511     Size = 4;
512     AddThumbPredicate(MI);
513     return result;
514   }
515 
516   MI.clear();
517   result = decodeVFPInstruction32(MI, insn32, Address, this);
518   if (result != Fail) {
519     Size = 4;
520     UpdateThumbVFPPredicate(MI);
521     return result;
522   }
523 
524   MI.clear();
525   result = decodeNEONDupInstruction32(MI, insn32, Address, this);
526   if (result != Fail) {
527     Size = 4;
528     AddThumbPredicate(MI);
529     return result;
530   }
531 
532   if (fieldFromInstruction32(insn32, 24, 8) == 0xF9) {
533     MI.clear();
534     uint32_t NEONLdStInsn = insn32;
535     NEONLdStInsn &= 0xF0FFFFFF;
536     NEONLdStInsn |= 0x04000000;
537     result = decodeNEONLoadStoreInstruction32(MI, NEONLdStInsn, Address, this);
538     if (result != Fail) {
539       Size = 4;
540       AddThumbPredicate(MI);
541       return result;
542     }
543   }
544 
545   if (fieldFromInstruction32(insn32, 24, 4) == 0xF) {
546     MI.clear();
547     uint32_t NEONDataInsn = insn32;
548     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
549     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
550     NEONDataInsn |= 0x12000000; // Set bits 28 and 25
551     result = decodeNEONDataInstruction32(MI, NEONDataInsn, Address, this);
552     if (result != Fail) {
553       Size = 4;
554       AddThumbPredicate(MI);
555       return result;
556     }
557   }
558 
559   return Fail;
560 }
561 
562 
563 extern "C" void LLVMInitializeARMDisassembler() {
564   TargetRegistry::RegisterMCDisassembler(TheARMTarget,
565                                          createARMDisassembler);
566   TargetRegistry::RegisterMCDisassembler(TheThumbTarget,
567                                          createThumbDisassembler);
568 }
569 
570 static const unsigned GPRDecoderTable[] = {
571   ARM::R0, ARM::R1, ARM::R2, ARM::R3,
572   ARM::R4, ARM::R5, ARM::R6, ARM::R7,
573   ARM::R8, ARM::R9, ARM::R10, ARM::R11,
574   ARM::R12, ARM::SP, ARM::LR, ARM::PC
575 };
576 
577 static DecodeStatus DecodeGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
578                                    uint64_t Address, const void *Decoder) {
579   if (RegNo > 15)
580     return Fail;
581 
582   unsigned Register = GPRDecoderTable[RegNo];
583   Inst.addOperand(MCOperand::CreateReg(Register));
584   return Success;
585 }
586 
587 static DecodeStatus
588 DecodeGPRnopcRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
589                            uint64_t Address, const void *Decoder) {
590   if (RegNo == 15) return Fail;
591   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
592 }
593 
594 static DecodeStatus DecodetGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
595                                    uint64_t Address, const void *Decoder) {
596   if (RegNo > 7)
597     return Fail;
598   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
599 }
600 
601 static DecodeStatus DecodetcGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
602                                    uint64_t Address, const void *Decoder) {
603   unsigned Register = 0;
604   switch (RegNo) {
605     case 0:
606       Register = ARM::R0;
607       break;
608     case 1:
609       Register = ARM::R1;
610       break;
611     case 2:
612       Register = ARM::R2;
613       break;
614     case 3:
615       Register = ARM::R3;
616       break;
617     case 9:
618       Register = ARM::R9;
619       break;
620     case 12:
621       Register = ARM::R12;
622       break;
623     default:
624       return Fail;
625     }
626 
627   Inst.addOperand(MCOperand::CreateReg(Register));
628   return Success;
629 }
630 
631 static DecodeStatus DecoderGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
632                                    uint64_t Address, const void *Decoder) {
633   if (RegNo == 13 || RegNo == 15) return Fail;
634   return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
635 }
636 
637 static const unsigned SPRDecoderTable[] = {
638      ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
639      ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
640      ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
641     ARM::S12, ARM::S13, ARM::S14, ARM::S15,
642     ARM::S16, ARM::S17, ARM::S18, ARM::S19,
643     ARM::S20, ARM::S21, ARM::S22, ARM::S23,
644     ARM::S24, ARM::S25, ARM::S26, ARM::S27,
645     ARM::S28, ARM::S29, ARM::S30, ARM::S31
646 };
647 
648 static DecodeStatus DecodeSPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
649                                    uint64_t Address, const void *Decoder) {
650   if (RegNo > 31)
651     return Fail;
652 
653   unsigned Register = SPRDecoderTable[RegNo];
654   Inst.addOperand(MCOperand::CreateReg(Register));
655   return Success;
656 }
657 
658 static const unsigned DPRDecoderTable[] = {
659      ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
660      ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
661      ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
662     ARM::D12, ARM::D13, ARM::D14, ARM::D15,
663     ARM::D16, ARM::D17, ARM::D18, ARM::D19,
664     ARM::D20, ARM::D21, ARM::D22, ARM::D23,
665     ARM::D24, ARM::D25, ARM::D26, ARM::D27,
666     ARM::D28, ARM::D29, ARM::D30, ARM::D31
667 };
668 
669 static DecodeStatus DecodeDPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
670                                    uint64_t Address, const void *Decoder) {
671   if (RegNo > 31)
672     return Fail;
673 
674   unsigned Register = DPRDecoderTable[RegNo];
675   Inst.addOperand(MCOperand::CreateReg(Register));
676   return Success;
677 }
678 
679 static DecodeStatus DecodeDPR_8RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
680                                    uint64_t Address, const void *Decoder) {
681   if (RegNo > 7)
682     return Fail;
683   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
684 }
685 
686 static DecodeStatus
687 DecodeDPR_VFP2RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
688                             uint64_t Address, const void *Decoder) {
689   if (RegNo > 15)
690     return Fail;
691   return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
692 }
693 
694 static const unsigned QPRDecoderTable[] = {
695      ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
696      ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
697      ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
698     ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
699 };
700 
701 
702 static DecodeStatus DecodeQPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
703                                    uint64_t Address, const void *Decoder) {
704   if (RegNo > 31)
705     return Fail;
706   RegNo >>= 1;
707 
708   unsigned Register = QPRDecoderTable[RegNo];
709   Inst.addOperand(MCOperand::CreateReg(Register));
710   return Success;
711 }
712 
713 static DecodeStatus DecodePredicateOperand(llvm::MCInst &Inst, unsigned Val,
714                                uint64_t Address, const void *Decoder) {
715   if (Val == 0xF) return Fail;
716   // AL predicate is not allowed on Thumb1 branches.
717   if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
718     return Fail;
719   Inst.addOperand(MCOperand::CreateImm(Val));
720   if (Val == ARMCC::AL) {
721     Inst.addOperand(MCOperand::CreateReg(0));
722   } else
723     Inst.addOperand(MCOperand::CreateReg(ARM::CPSR));
724   return Success;
725 }
726 
727 static DecodeStatus DecodeCCOutOperand(llvm::MCInst &Inst, unsigned Val,
728                                uint64_t Address, const void *Decoder) {
729   if (Val)
730     Inst.addOperand(MCOperand::CreateReg(ARM::CPSR));
731   else
732     Inst.addOperand(MCOperand::CreateReg(0));
733   return Success;
734 }
735 
736 static DecodeStatus DecodeSOImmOperand(llvm::MCInst &Inst, unsigned Val,
737                                uint64_t Address, const void *Decoder) {
738   uint32_t imm = Val & 0xFF;
739   uint32_t rot = (Val & 0xF00) >> 7;
740   uint32_t rot_imm = (imm >> rot) | (imm << (32-rot));
741   Inst.addOperand(MCOperand::CreateImm(rot_imm));
742   return Success;
743 }
744 
745 static DecodeStatus DecodeBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
746                                uint64_t Address, const void *Decoder) {
747   Val <<= 2;
748   Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(Val)));
749   return Success;
750 }
751 
752 static DecodeStatus DecodeSORegImmOperand(llvm::MCInst &Inst, unsigned Val,
753                                uint64_t Address, const void *Decoder) {
754   DecodeStatus S = Success;
755 
756   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
757   unsigned type = fieldFromInstruction32(Val, 5, 2);
758   unsigned imm = fieldFromInstruction32(Val, 7, 5);
759 
760   // Register-immediate
761   CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
762 
763   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
764   switch (type) {
765     case 0:
766       Shift = ARM_AM::lsl;
767       break;
768     case 1:
769       Shift = ARM_AM::lsr;
770       break;
771     case 2:
772       Shift = ARM_AM::asr;
773       break;
774     case 3:
775       Shift = ARM_AM::ror;
776       break;
777   }
778 
779   if (Shift == ARM_AM::ror && imm == 0)
780     Shift = ARM_AM::rrx;
781 
782   unsigned Op = Shift | (imm << 3);
783   Inst.addOperand(MCOperand::CreateImm(Op));
784 
785   return S;
786 }
787 
788 static DecodeStatus DecodeSORegRegOperand(llvm::MCInst &Inst, unsigned Val,
789                                uint64_t Address, const void *Decoder) {
790   DecodeStatus S = Success;
791 
792   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
793   unsigned type = fieldFromInstruction32(Val, 5, 2);
794   unsigned Rs = fieldFromInstruction32(Val, 8, 4);
795 
796   // Register-register
797   CHECK(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder));
798   CHECK(S, DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder));
799 
800   ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
801   switch (type) {
802     case 0:
803       Shift = ARM_AM::lsl;
804       break;
805     case 1:
806       Shift = ARM_AM::lsr;
807       break;
808     case 2:
809       Shift = ARM_AM::asr;
810       break;
811     case 3:
812       Shift = ARM_AM::ror;
813       break;
814   }
815 
816   Inst.addOperand(MCOperand::CreateImm(Shift));
817 
818   return S;
819 }
820 
821 static DecodeStatus DecodeRegListOperand(llvm::MCInst &Inst, unsigned Val,
822                                  uint64_t Address, const void *Decoder) {
823   DecodeStatus S = Success;
824 
825   // Empty register lists are not allowed.
826   if (CountPopulation_32(Val) == 0) return Fail;
827   for (unsigned i = 0; i < 16; ++i) {
828     if (Val & (1 << i)) {
829       CHECK(S, DecodeGPRRegisterClass(Inst, i, Address, Decoder));
830     }
831   }
832 
833   return S;
834 }
835 
836 static DecodeStatus DecodeSPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
837                                  uint64_t Address, const void *Decoder) {
838   DecodeStatus S = Success;
839 
840   unsigned Vd = fieldFromInstruction32(Val, 8, 4);
841   unsigned regs = Val & 0xFF;
842 
843   CHECK(S, DecodeSPRRegisterClass(Inst, Vd, Address, Decoder));
844   for (unsigned i = 0; i < (regs - 1); ++i) {
845     CHECK(S, DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder));
846   }
847 
848   return S;
849 }
850 
851 static DecodeStatus DecodeDPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
852                                  uint64_t Address, const void *Decoder) {
853   DecodeStatus S = Success;
854 
855   unsigned Vd = fieldFromInstruction32(Val, 8, 4);
856   unsigned regs = (Val & 0xFF) / 2;
857 
858   CHECK(S, DecodeDPRRegisterClass(Inst, Vd, Address, Decoder));
859   for (unsigned i = 0; i < (regs - 1); ++i) {
860     CHECK(S, DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder));
861   }
862 
863   return S;
864 }
865 
866 static DecodeStatus DecodeBitfieldMaskOperand(llvm::MCInst &Inst, unsigned Val,
867                                       uint64_t Address, const void *Decoder) {
868   // This operand encodes a mask of contiguous zeros between a specified MSB
869   // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
870   // the mask of all bits LSB-and-lower, and then xor them to create
871   // the mask of that's all ones on [msb, lsb].  Finally we not it to
872   // create the final mask.
873   unsigned msb = fieldFromInstruction32(Val, 5, 5);
874   unsigned lsb = fieldFromInstruction32(Val, 0, 5);
875   uint32_t msb_mask = (1 << (msb+1)) - 1;
876   uint32_t lsb_mask = (1 << lsb) - 1;
877   Inst.addOperand(MCOperand::CreateImm(~(msb_mask ^ lsb_mask)));
878   return Success;
879 }
880 
881 static DecodeStatus DecodeCopMemInstruction(llvm::MCInst &Inst, unsigned Insn,
882                                   uint64_t Address, const void *Decoder) {
883   DecodeStatus S = Success;
884 
885   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
886   unsigned CRd = fieldFromInstruction32(Insn, 12, 4);
887   unsigned coproc = fieldFromInstruction32(Insn, 8, 4);
888   unsigned imm = fieldFromInstruction32(Insn, 0, 8);
889   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
890   unsigned U = fieldFromInstruction32(Insn, 23, 1);
891 
892   switch (Inst.getOpcode()) {
893     case ARM::LDC_OFFSET:
894     case ARM::LDC_PRE:
895     case ARM::LDC_POST:
896     case ARM::LDC_OPTION:
897     case ARM::LDCL_OFFSET:
898     case ARM::LDCL_PRE:
899     case ARM::LDCL_POST:
900     case ARM::LDCL_OPTION:
901     case ARM::STC_OFFSET:
902     case ARM::STC_PRE:
903     case ARM::STC_POST:
904     case ARM::STC_OPTION:
905     case ARM::STCL_OFFSET:
906     case ARM::STCL_PRE:
907     case ARM::STCL_POST:
908     case ARM::STCL_OPTION:
909       if (coproc == 0xA || coproc == 0xB)
910         return Fail;
911       break;
912     default:
913       break;
914   }
915 
916   Inst.addOperand(MCOperand::CreateImm(coproc));
917   Inst.addOperand(MCOperand::CreateImm(CRd));
918   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
919   switch (Inst.getOpcode()) {
920     case ARM::LDC_OPTION:
921     case ARM::LDCL_OPTION:
922     case ARM::LDC2_OPTION:
923     case ARM::LDC2L_OPTION:
924     case ARM::STC_OPTION:
925     case ARM::STCL_OPTION:
926     case ARM::STC2_OPTION:
927     case ARM::STC2L_OPTION:
928     case ARM::LDCL_POST:
929     case ARM::STCL_POST:
930       break;
931     default:
932       Inst.addOperand(MCOperand::CreateReg(0));
933       break;
934   }
935 
936   unsigned P = fieldFromInstruction32(Insn, 24, 1);
937   unsigned W = fieldFromInstruction32(Insn, 21, 1);
938 
939   bool writeback = (P == 0) || (W == 1);
940   unsigned idx_mode = 0;
941   if (P && writeback)
942     idx_mode = ARMII::IndexModePre;
943   else if (!P && writeback)
944     idx_mode = ARMII::IndexModePost;
945 
946   switch (Inst.getOpcode()) {
947     case ARM::LDCL_POST:
948     case ARM::STCL_POST:
949       imm |= U << 8;
950     case ARM::LDC_OPTION:
951     case ARM::LDCL_OPTION:
952     case ARM::LDC2_OPTION:
953     case ARM::LDC2L_OPTION:
954     case ARM::STC_OPTION:
955     case ARM::STCL_OPTION:
956     case ARM::STC2_OPTION:
957     case ARM::STC2L_OPTION:
958       Inst.addOperand(MCOperand::CreateImm(imm));
959       break;
960     default:
961       if (U)
962         Inst.addOperand(MCOperand::CreateImm(
963             ARM_AM::getAM2Opc(ARM_AM::add, imm, ARM_AM::lsl, idx_mode)));
964       else
965         Inst.addOperand(MCOperand::CreateImm(
966             ARM_AM::getAM2Opc(ARM_AM::sub, imm, ARM_AM::lsl, idx_mode)));
967       break;
968   }
969 
970   switch (Inst.getOpcode()) {
971     case ARM::LDC_OFFSET:
972     case ARM::LDC_PRE:
973     case ARM::LDC_POST:
974     case ARM::LDC_OPTION:
975     case ARM::LDCL_OFFSET:
976     case ARM::LDCL_PRE:
977     case ARM::LDCL_POST:
978     case ARM::LDCL_OPTION:
979     case ARM::STC_OFFSET:
980     case ARM::STC_PRE:
981     case ARM::STC_POST:
982     case ARM::STC_OPTION:
983     case ARM::STCL_OFFSET:
984     case ARM::STCL_PRE:
985     case ARM::STCL_POST:
986     case ARM::STCL_OPTION:
987       CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
988       break;
989     default:
990       break;
991   }
992 
993   return S;
994 }
995 
996 static DecodeStatus
997 DecodeAddrMode2IdxInstruction(llvm::MCInst &Inst, unsigned Insn,
998                               uint64_t Address, const void *Decoder) {
999   DecodeStatus S = Success;
1000 
1001   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1002   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
1003   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1004   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
1005   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1006   unsigned reg = fieldFromInstruction32(Insn, 25, 1);
1007   unsigned P = fieldFromInstruction32(Insn, 24, 1);
1008   unsigned W = fieldFromInstruction32(Insn, 21, 1);
1009 
1010   // On stores, the writeback operand precedes Rt.
1011   switch (Inst.getOpcode()) {
1012     case ARM::STR_POST_IMM:
1013     case ARM::STR_POST_REG:
1014     case ARM::STRB_POST_IMM:
1015     case ARM::STRB_POST_REG:
1016     case ARM::STRT_POST_REG:
1017     case ARM::STRT_POST_IMM:
1018     case ARM::STRBT_POST_REG:
1019     case ARM::STRBT_POST_IMM:
1020       CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1021       break;
1022     default:
1023       break;
1024   }
1025 
1026   CHECK(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
1027 
1028   // On loads, the writeback operand comes after Rt.
1029   switch (Inst.getOpcode()) {
1030     case ARM::LDR_POST_IMM:
1031     case ARM::LDR_POST_REG:
1032     case ARM::LDRB_POST_IMM:
1033     case ARM::LDRB_POST_REG:
1034     case ARM::LDR_PRE:
1035     case ARM::LDRB_PRE:
1036     case ARM::LDRBT_POST_REG:
1037     case ARM::LDRBT_POST_IMM:
1038     case ARM::LDRT_POST_REG:
1039     case ARM::LDRT_POST_IMM:
1040       CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1041       break;
1042     default:
1043       break;
1044   }
1045 
1046   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1047 
1048   ARM_AM::AddrOpc Op = ARM_AM::add;
1049   if (!fieldFromInstruction32(Insn, 23, 1))
1050     Op = ARM_AM::sub;
1051 
1052   bool writeback = (P == 0) || (W == 1);
1053   unsigned idx_mode = 0;
1054   if (P && writeback)
1055     idx_mode = ARMII::IndexModePre;
1056   else if (!P && writeback)
1057     idx_mode = ARMII::IndexModePost;
1058 
1059   if (writeback && (Rn == 15 || Rn == Rt)) S = Unpredictable; // UNPREDICTABLE
1060 
1061   if (reg) {
1062     CHECK(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder));
1063     ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1064     switch( fieldFromInstruction32(Insn, 5, 2)) {
1065       case 0:
1066         Opc = ARM_AM::lsl;
1067         break;
1068       case 1:
1069         Opc = ARM_AM::lsr;
1070         break;
1071       case 2:
1072         Opc = ARM_AM::asr;
1073         break;
1074       case 3:
1075         Opc = ARM_AM::ror;
1076         break;
1077       default:
1078         return Fail;
1079     }
1080     unsigned amt = fieldFromInstruction32(Insn, 7, 5);
1081     unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1082 
1083     Inst.addOperand(MCOperand::CreateImm(imm));
1084   } else {
1085     Inst.addOperand(MCOperand::CreateReg(0));
1086     unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1087     Inst.addOperand(MCOperand::CreateImm(tmp));
1088   }
1089 
1090   CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
1091 
1092   return S;
1093 }
1094 
1095 static DecodeStatus DecodeSORegMemOperand(llvm::MCInst &Inst, unsigned Val,
1096                                   uint64_t Address, const void *Decoder) {
1097   DecodeStatus S = Success;
1098 
1099   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
1100   unsigned Rm = fieldFromInstruction32(Val,  0, 4);
1101   unsigned type = fieldFromInstruction32(Val, 5, 2);
1102   unsigned imm = fieldFromInstruction32(Val, 7, 5);
1103   unsigned U = fieldFromInstruction32(Val, 12, 1);
1104 
1105   ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1106   switch (type) {
1107     case 0:
1108       ShOp = ARM_AM::lsl;
1109       break;
1110     case 1:
1111       ShOp = ARM_AM::lsr;
1112       break;
1113     case 2:
1114       ShOp = ARM_AM::asr;
1115       break;
1116     case 3:
1117       ShOp = ARM_AM::ror;
1118       break;
1119   }
1120 
1121   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1122   CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
1123   unsigned shift;
1124   if (U)
1125     shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1126   else
1127     shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1128   Inst.addOperand(MCOperand::CreateImm(shift));
1129 
1130   return S;
1131 }
1132 
1133 static DecodeStatus
1134 DecodeAddrMode3Instruction(llvm::MCInst &Inst, unsigned Insn,
1135                            uint64_t Address, const void *Decoder) {
1136   DecodeStatus S = Success;
1137 
1138   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
1139   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1140   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1141   unsigned type = fieldFromInstruction32(Insn, 22, 1);
1142   unsigned imm = fieldFromInstruction32(Insn, 8, 4);
1143   unsigned U = ((~fieldFromInstruction32(Insn, 23, 1)) & 1) << 8;
1144   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1145   unsigned W = fieldFromInstruction32(Insn, 21, 1);
1146   unsigned P = fieldFromInstruction32(Insn, 24, 1);
1147 
1148   bool writeback = (W == 1) | (P == 0);
1149 
1150   // For {LD,ST}RD, Rt must be even, else undefined.
1151   switch (Inst.getOpcode()) {
1152     case ARM::STRD:
1153     case ARM::STRD_PRE:
1154     case ARM::STRD_POST:
1155     case ARM::LDRD:
1156     case ARM::LDRD_PRE:
1157     case ARM::LDRD_POST:
1158       if (Rt & 0x1) return Fail;
1159       break;
1160   default:
1161     break;
1162   }
1163 
1164   if (writeback) { // Writeback
1165     if (P)
1166       U |= ARMII::IndexModePre << 9;
1167     else
1168       U |= ARMII::IndexModePost << 9;
1169 
1170     // On stores, the writeback operand precedes Rt.
1171     switch (Inst.getOpcode()) {
1172     case ARM::STRD:
1173     case ARM::STRD_PRE:
1174     case ARM::STRD_POST:
1175     case ARM::STRH:
1176     case ARM::STRH_PRE:
1177     case ARM::STRH_POST:
1178       CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1179       break;
1180     default:
1181       break;
1182     }
1183   }
1184 
1185   CHECK(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
1186   switch (Inst.getOpcode()) {
1187     case ARM::STRD:
1188     case ARM::STRD_PRE:
1189     case ARM::STRD_POST:
1190     case ARM::LDRD:
1191     case ARM::LDRD_PRE:
1192     case ARM::LDRD_POST:
1193       CHECK(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder));
1194       break;
1195     default:
1196       break;
1197   }
1198 
1199   if (writeback) {
1200     // On loads, the writeback operand comes after Rt.
1201     switch (Inst.getOpcode()) {
1202     case ARM::LDRD:
1203     case ARM::LDRD_PRE:
1204     case ARM::LDRD_POST:
1205     case ARM::LDRH:
1206     case ARM::LDRH_PRE:
1207     case ARM::LDRH_POST:
1208     case ARM::LDRSH:
1209     case ARM::LDRSH_PRE:
1210     case ARM::LDRSH_POST:
1211     case ARM::LDRSB:
1212     case ARM::LDRSB_PRE:
1213     case ARM::LDRSB_POST:
1214     case ARM::LDRHTr:
1215     case ARM::LDRSBTr:
1216       CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1217       break;
1218     default:
1219       break;
1220     }
1221   }
1222 
1223   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1224 
1225   if (type) {
1226     Inst.addOperand(MCOperand::CreateReg(0));
1227     Inst.addOperand(MCOperand::CreateImm(U | (imm << 4) | Rm));
1228   } else {
1229     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
1230     Inst.addOperand(MCOperand::CreateImm(U));
1231   }
1232 
1233   CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
1234 
1235   return S;
1236 }
1237 
1238 static DecodeStatus DecodeRFEInstruction(llvm::MCInst &Inst, unsigned Insn,
1239                                  uint64_t Address, const void *Decoder) {
1240   DecodeStatus S = Success;
1241 
1242   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1243   unsigned mode = fieldFromInstruction32(Insn, 23, 2);
1244 
1245   switch (mode) {
1246     case 0:
1247       mode = ARM_AM::da;
1248       break;
1249     case 1:
1250       mode = ARM_AM::ia;
1251       break;
1252     case 2:
1253       mode = ARM_AM::db;
1254       break;
1255     case 3:
1256       mode = ARM_AM::ib;
1257       break;
1258   }
1259 
1260   Inst.addOperand(MCOperand::CreateImm(mode));
1261   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1262 
1263   return S;
1264 }
1265 
1266 static DecodeStatus DecodeMemMultipleWritebackInstruction(llvm::MCInst &Inst,
1267                                   unsigned Insn,
1268                                   uint64_t Address, const void *Decoder) {
1269   DecodeStatus S = Success;
1270 
1271   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1272   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1273   unsigned reglist = fieldFromInstruction32(Insn, 0, 16);
1274 
1275   if (pred == 0xF) {
1276     switch (Inst.getOpcode()) {
1277       case ARM::STMDA:
1278         Inst.setOpcode(ARM::RFEDA);
1279         break;
1280       case ARM::STMDA_UPD:
1281         Inst.setOpcode(ARM::RFEDA_UPD);
1282         break;
1283       case ARM::STMDB:
1284         Inst.setOpcode(ARM::RFEDB);
1285         break;
1286       case ARM::STMDB_UPD:
1287         Inst.setOpcode(ARM::RFEDB_UPD);
1288         break;
1289       case ARM::STMIA:
1290         Inst.setOpcode(ARM::RFEIA);
1291         break;
1292       case ARM::STMIA_UPD:
1293         Inst.setOpcode(ARM::RFEIA_UPD);
1294         break;
1295       case ARM::STMIB:
1296         Inst.setOpcode(ARM::RFEIB);
1297         break;
1298       case ARM::STMIB_UPD:
1299         Inst.setOpcode(ARM::RFEIB_UPD);
1300         break;
1301     }
1302     return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
1303   }
1304 
1305   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1306   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)); // Tied
1307   CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
1308   CHECK(S, DecodeRegListOperand(Inst, reglist, Address, Decoder));
1309 
1310   return S;
1311 }
1312 
1313 static DecodeStatus DecodeCPSInstruction(llvm::MCInst &Inst, unsigned Insn,
1314                                  uint64_t Address, const void *Decoder) {
1315   unsigned imod = fieldFromInstruction32(Insn, 18, 2);
1316   unsigned M = fieldFromInstruction32(Insn, 17, 1);
1317   unsigned iflags = fieldFromInstruction32(Insn, 6, 3);
1318   unsigned mode = fieldFromInstruction32(Insn, 0, 5);
1319 
1320   DecodeStatus S = Success;
1321 
1322   // imod == '01' --> UNPREDICTABLE
1323   // NOTE: Even though this is technically UNPREDICTABLE, we choose to
1324   // return failure here.  The '01' imod value is unprintable, so there's
1325   // nothing useful we could do even if we returned UNPREDICTABLE.
1326 
1327   if (imod == 1) CHECK(S, Fail);
1328 
1329   if (imod && M) {
1330     Inst.setOpcode(ARM::CPS3p);
1331     Inst.addOperand(MCOperand::CreateImm(imod));
1332     Inst.addOperand(MCOperand::CreateImm(iflags));
1333     Inst.addOperand(MCOperand::CreateImm(mode));
1334   } else if (imod && !M) {
1335     Inst.setOpcode(ARM::CPS2p);
1336     Inst.addOperand(MCOperand::CreateImm(imod));
1337     Inst.addOperand(MCOperand::CreateImm(iflags));
1338     if (mode) CHECK(S, Unpredictable);
1339   } else if (!imod && M) {
1340     Inst.setOpcode(ARM::CPS1p);
1341     Inst.addOperand(MCOperand::CreateImm(mode));
1342     if (iflags) CHECK(S, Unpredictable);
1343   } else
1344     // imod == '00' && M == '0' --> UNPREDICTABLE
1345     CHECK(S, Unpredictable);
1346 
1347   return S;
1348 }
1349 
1350 static DecodeStatus DecodeSMLAInstruction(llvm::MCInst &Inst, unsigned Insn,
1351                                  uint64_t Address, const void *Decoder) {
1352   DecodeStatus S = Success;
1353 
1354   unsigned Rd = fieldFromInstruction32(Insn, 16, 4);
1355   unsigned Rn = fieldFromInstruction32(Insn, 0, 4);
1356   unsigned Rm = fieldFromInstruction32(Insn, 8, 4);
1357   unsigned Ra = fieldFromInstruction32(Insn, 12, 4);
1358   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1359 
1360   if (pred == 0xF)
1361     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
1362 
1363   CHECK(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder));
1364   CHECK(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder));
1365   CHECK(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder));
1366   CHECK(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder));
1367 
1368   CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
1369 
1370   return S;
1371 }
1372 
1373 static DecodeStatus DecodeAddrModeImm12Operand(llvm::MCInst &Inst, unsigned Val,
1374                            uint64_t Address, const void *Decoder) {
1375   DecodeStatus S = Success;
1376 
1377   unsigned add = fieldFromInstruction32(Val, 12, 1);
1378   unsigned imm = fieldFromInstruction32(Val, 0, 12);
1379   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
1380 
1381   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1382 
1383   if (!add) imm *= -1;
1384   if (imm == 0 && !add) imm = INT32_MIN;
1385   Inst.addOperand(MCOperand::CreateImm(imm));
1386 
1387   return S;
1388 }
1389 
1390 static DecodeStatus DecodeAddrMode5Operand(llvm::MCInst &Inst, unsigned Val,
1391                                    uint64_t Address, const void *Decoder) {
1392   DecodeStatus S = Success;
1393 
1394   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
1395   unsigned U = fieldFromInstruction32(Val, 8, 1);
1396   unsigned imm = fieldFromInstruction32(Val, 0, 8);
1397 
1398   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1399 
1400   if (U)
1401     Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
1402   else
1403     Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
1404 
1405   return S;
1406 }
1407 
1408 static DecodeStatus DecodeAddrMode7Operand(llvm::MCInst &Inst, unsigned Val,
1409                                    uint64_t Address, const void *Decoder) {
1410   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
1411 }
1412 
1413 static DecodeStatus
1414 DecodeBranchImmInstruction(llvm::MCInst &Inst, unsigned Insn,
1415                            uint64_t Address, const void *Decoder) {
1416   DecodeStatus S = Success;
1417 
1418   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1419   unsigned imm = fieldFromInstruction32(Insn, 0, 24) << 2;
1420 
1421   if (pred == 0xF) {
1422     Inst.setOpcode(ARM::BLXi);
1423     imm |= fieldFromInstruction32(Insn, 24, 1) << 1;
1424     Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1425     return S;
1426   }
1427 
1428   Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1429   CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
1430 
1431   return S;
1432 }
1433 
1434 
1435 static DecodeStatus DecodeVCVTImmOperand(llvm::MCInst &Inst, unsigned Val,
1436                                  uint64_t Address, const void *Decoder) {
1437   Inst.addOperand(MCOperand::CreateImm(64 - Val));
1438   return Success;
1439 }
1440 
1441 static DecodeStatus DecodeAddrMode6Operand(llvm::MCInst &Inst, unsigned Val,
1442                                    uint64_t Address, const void *Decoder) {
1443   DecodeStatus S = Success;
1444 
1445   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
1446   unsigned align = fieldFromInstruction32(Val, 4, 2);
1447 
1448   CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
1449   if (!align)
1450     Inst.addOperand(MCOperand::CreateImm(0));
1451   else
1452     Inst.addOperand(MCOperand::CreateImm(4 << align));
1453 
1454   return S;
1455 }
1456 
1457 static DecodeStatus DecodeVLDInstruction(llvm::MCInst &Inst, unsigned Insn,
1458                                    uint64_t Address, const void *Decoder) {
1459   DecodeStatus S = Success;
1460 
1461   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1462   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1463   unsigned wb = fieldFromInstruction32(Insn, 16, 4);
1464   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1465   Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
1466   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1467 
1468   // First output register
1469   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
1470 
1471   // Second output register
1472   switch (Inst.getOpcode()) {
1473     case ARM::VLD1q8:
1474     case ARM::VLD1q16:
1475     case ARM::VLD1q32:
1476     case ARM::VLD1q64:
1477     case ARM::VLD1q8_UPD:
1478     case ARM::VLD1q16_UPD:
1479     case ARM::VLD1q32_UPD:
1480     case ARM::VLD1q64_UPD:
1481     case ARM::VLD1d8T:
1482     case ARM::VLD1d16T:
1483     case ARM::VLD1d32T:
1484     case ARM::VLD1d64T:
1485     case ARM::VLD1d8T_UPD:
1486     case ARM::VLD1d16T_UPD:
1487     case ARM::VLD1d32T_UPD:
1488     case ARM::VLD1d64T_UPD:
1489     case ARM::VLD1d8Q:
1490     case ARM::VLD1d16Q:
1491     case ARM::VLD1d32Q:
1492     case ARM::VLD1d64Q:
1493     case ARM::VLD1d8Q_UPD:
1494     case ARM::VLD1d16Q_UPD:
1495     case ARM::VLD1d32Q_UPD:
1496     case ARM::VLD1d64Q_UPD:
1497     case ARM::VLD2d8:
1498     case ARM::VLD2d16:
1499     case ARM::VLD2d32:
1500     case ARM::VLD2d8_UPD:
1501     case ARM::VLD2d16_UPD:
1502     case ARM::VLD2d32_UPD:
1503     case ARM::VLD2q8:
1504     case ARM::VLD2q16:
1505     case ARM::VLD2q32:
1506     case ARM::VLD2q8_UPD:
1507     case ARM::VLD2q16_UPD:
1508     case ARM::VLD2q32_UPD:
1509     case ARM::VLD3d8:
1510     case ARM::VLD3d16:
1511     case ARM::VLD3d32:
1512     case ARM::VLD3d8_UPD:
1513     case ARM::VLD3d16_UPD:
1514     case ARM::VLD3d32_UPD:
1515     case ARM::VLD4d8:
1516     case ARM::VLD4d16:
1517     case ARM::VLD4d32:
1518     case ARM::VLD4d8_UPD:
1519     case ARM::VLD4d16_UPD:
1520     case ARM::VLD4d32_UPD:
1521       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder));
1522       break;
1523     case ARM::VLD2b8:
1524     case ARM::VLD2b16:
1525     case ARM::VLD2b32:
1526     case ARM::VLD2b8_UPD:
1527     case ARM::VLD2b16_UPD:
1528     case ARM::VLD2b32_UPD:
1529     case ARM::VLD3q8:
1530     case ARM::VLD3q16:
1531     case ARM::VLD3q32:
1532     case ARM::VLD3q8_UPD:
1533     case ARM::VLD3q16_UPD:
1534     case ARM::VLD3q32_UPD:
1535     case ARM::VLD4q8:
1536     case ARM::VLD4q16:
1537     case ARM::VLD4q32:
1538     case ARM::VLD4q8_UPD:
1539     case ARM::VLD4q16_UPD:
1540     case ARM::VLD4q32_UPD:
1541       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder));
1542     default:
1543       break;
1544   }
1545 
1546   // Third output register
1547   switch(Inst.getOpcode()) {
1548     case ARM::VLD1d8T:
1549     case ARM::VLD1d16T:
1550     case ARM::VLD1d32T:
1551     case ARM::VLD1d64T:
1552     case ARM::VLD1d8T_UPD:
1553     case ARM::VLD1d16T_UPD:
1554     case ARM::VLD1d32T_UPD:
1555     case ARM::VLD1d64T_UPD:
1556     case ARM::VLD1d8Q:
1557     case ARM::VLD1d16Q:
1558     case ARM::VLD1d32Q:
1559     case ARM::VLD1d64Q:
1560     case ARM::VLD1d8Q_UPD:
1561     case ARM::VLD1d16Q_UPD:
1562     case ARM::VLD1d32Q_UPD:
1563     case ARM::VLD1d64Q_UPD:
1564     case ARM::VLD2q8:
1565     case ARM::VLD2q16:
1566     case ARM::VLD2q32:
1567     case ARM::VLD2q8_UPD:
1568     case ARM::VLD2q16_UPD:
1569     case ARM::VLD2q32_UPD:
1570     case ARM::VLD3d8:
1571     case ARM::VLD3d16:
1572     case ARM::VLD3d32:
1573     case ARM::VLD3d8_UPD:
1574     case ARM::VLD3d16_UPD:
1575     case ARM::VLD3d32_UPD:
1576     case ARM::VLD4d8:
1577     case ARM::VLD4d16:
1578     case ARM::VLD4d32:
1579     case ARM::VLD4d8_UPD:
1580     case ARM::VLD4d16_UPD:
1581     case ARM::VLD4d32_UPD:
1582       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder));
1583       break;
1584     case ARM::VLD3q8:
1585     case ARM::VLD3q16:
1586     case ARM::VLD3q32:
1587     case ARM::VLD3q8_UPD:
1588     case ARM::VLD3q16_UPD:
1589     case ARM::VLD3q32_UPD:
1590     case ARM::VLD4q8:
1591     case ARM::VLD4q16:
1592     case ARM::VLD4q32:
1593     case ARM::VLD4q8_UPD:
1594     case ARM::VLD4q16_UPD:
1595     case ARM::VLD4q32_UPD:
1596       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder));
1597       break;
1598     default:
1599       break;
1600   }
1601 
1602   // Fourth output register
1603   switch (Inst.getOpcode()) {
1604     case ARM::VLD1d8Q:
1605     case ARM::VLD1d16Q:
1606     case ARM::VLD1d32Q:
1607     case ARM::VLD1d64Q:
1608     case ARM::VLD1d8Q_UPD:
1609     case ARM::VLD1d16Q_UPD:
1610     case ARM::VLD1d32Q_UPD:
1611     case ARM::VLD1d64Q_UPD:
1612     case ARM::VLD2q8:
1613     case ARM::VLD2q16:
1614     case ARM::VLD2q32:
1615     case ARM::VLD2q8_UPD:
1616     case ARM::VLD2q16_UPD:
1617     case ARM::VLD2q32_UPD:
1618     case ARM::VLD4d8:
1619     case ARM::VLD4d16:
1620     case ARM::VLD4d32:
1621     case ARM::VLD4d8_UPD:
1622     case ARM::VLD4d16_UPD:
1623     case ARM::VLD4d32_UPD:
1624       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder));
1625       break;
1626     case ARM::VLD4q8:
1627     case ARM::VLD4q16:
1628     case ARM::VLD4q32:
1629     case ARM::VLD4q8_UPD:
1630     case ARM::VLD4q16_UPD:
1631     case ARM::VLD4q32_UPD:
1632       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder));
1633       break;
1634     default:
1635       break;
1636   }
1637 
1638   // Writeback operand
1639   switch (Inst.getOpcode()) {
1640     case ARM::VLD1d8_UPD:
1641     case ARM::VLD1d16_UPD:
1642     case ARM::VLD1d32_UPD:
1643     case ARM::VLD1d64_UPD:
1644     case ARM::VLD1q8_UPD:
1645     case ARM::VLD1q16_UPD:
1646     case ARM::VLD1q32_UPD:
1647     case ARM::VLD1q64_UPD:
1648     case ARM::VLD1d8T_UPD:
1649     case ARM::VLD1d16T_UPD:
1650     case ARM::VLD1d32T_UPD:
1651     case ARM::VLD1d64T_UPD:
1652     case ARM::VLD1d8Q_UPD:
1653     case ARM::VLD1d16Q_UPD:
1654     case ARM::VLD1d32Q_UPD:
1655     case ARM::VLD1d64Q_UPD:
1656     case ARM::VLD2d8_UPD:
1657     case ARM::VLD2d16_UPD:
1658     case ARM::VLD2d32_UPD:
1659     case ARM::VLD2q8_UPD:
1660     case ARM::VLD2q16_UPD:
1661     case ARM::VLD2q32_UPD:
1662     case ARM::VLD2b8_UPD:
1663     case ARM::VLD2b16_UPD:
1664     case ARM::VLD2b32_UPD:
1665     case ARM::VLD3d8_UPD:
1666     case ARM::VLD3d16_UPD:
1667     case ARM::VLD3d32_UPD:
1668     case ARM::VLD3q8_UPD:
1669     case ARM::VLD3q16_UPD:
1670     case ARM::VLD3q32_UPD:
1671     case ARM::VLD4d8_UPD:
1672     case ARM::VLD4d16_UPD:
1673     case ARM::VLD4d32_UPD:
1674     case ARM::VLD4q8_UPD:
1675     case ARM::VLD4q16_UPD:
1676     case ARM::VLD4q32_UPD:
1677       CHECK(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder));
1678       break;
1679     default:
1680       break;
1681   }
1682 
1683   // AddrMode6 Base (register+alignment)
1684   CHECK(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder));
1685 
1686   // AddrMode6 Offset (register)
1687   if (Rm == 0xD)
1688     Inst.addOperand(MCOperand::CreateReg(0));
1689   else if (Rm != 0xF) {
1690     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
1691   }
1692 
1693   return S;
1694 }
1695 
1696 static DecodeStatus DecodeVSTInstruction(llvm::MCInst &Inst, unsigned Insn,
1697                                  uint64_t Address, const void *Decoder) {
1698   DecodeStatus S = Success;
1699 
1700   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1701   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1702   unsigned wb = fieldFromInstruction32(Insn, 16, 4);
1703   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1704   Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
1705   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1706 
1707   // Writeback Operand
1708   switch (Inst.getOpcode()) {
1709     case ARM::VST1d8_UPD:
1710     case ARM::VST1d16_UPD:
1711     case ARM::VST1d32_UPD:
1712     case ARM::VST1d64_UPD:
1713     case ARM::VST1q8_UPD:
1714     case ARM::VST1q16_UPD:
1715     case ARM::VST1q32_UPD:
1716     case ARM::VST1q64_UPD:
1717     case ARM::VST1d8T_UPD:
1718     case ARM::VST1d16T_UPD:
1719     case ARM::VST1d32T_UPD:
1720     case ARM::VST1d64T_UPD:
1721     case ARM::VST1d8Q_UPD:
1722     case ARM::VST1d16Q_UPD:
1723     case ARM::VST1d32Q_UPD:
1724     case ARM::VST1d64Q_UPD:
1725     case ARM::VST2d8_UPD:
1726     case ARM::VST2d16_UPD:
1727     case ARM::VST2d32_UPD:
1728     case ARM::VST2q8_UPD:
1729     case ARM::VST2q16_UPD:
1730     case ARM::VST2q32_UPD:
1731     case ARM::VST2b8_UPD:
1732     case ARM::VST2b16_UPD:
1733     case ARM::VST2b32_UPD:
1734     case ARM::VST3d8_UPD:
1735     case ARM::VST3d16_UPD:
1736     case ARM::VST3d32_UPD:
1737     case ARM::VST3q8_UPD:
1738     case ARM::VST3q16_UPD:
1739     case ARM::VST3q32_UPD:
1740     case ARM::VST4d8_UPD:
1741     case ARM::VST4d16_UPD:
1742     case ARM::VST4d32_UPD:
1743     case ARM::VST4q8_UPD:
1744     case ARM::VST4q16_UPD:
1745     case ARM::VST4q32_UPD:
1746       CHECK(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder));
1747       break;
1748     default:
1749       break;
1750   }
1751 
1752   // AddrMode6 Base (register+alignment)
1753   CHECK(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder));
1754 
1755   // AddrMode6 Offset (register)
1756   if (Rm == 0xD)
1757     Inst.addOperand(MCOperand::CreateReg(0));
1758   else if (Rm != 0xF) {
1759     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
1760   }
1761 
1762   // First input register
1763   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
1764 
1765   // Second input register
1766   switch (Inst.getOpcode()) {
1767     case ARM::VST1q8:
1768     case ARM::VST1q16:
1769     case ARM::VST1q32:
1770     case ARM::VST1q64:
1771     case ARM::VST1q8_UPD:
1772     case ARM::VST1q16_UPD:
1773     case ARM::VST1q32_UPD:
1774     case ARM::VST1q64_UPD:
1775     case ARM::VST1d8T:
1776     case ARM::VST1d16T:
1777     case ARM::VST1d32T:
1778     case ARM::VST1d64T:
1779     case ARM::VST1d8T_UPD:
1780     case ARM::VST1d16T_UPD:
1781     case ARM::VST1d32T_UPD:
1782     case ARM::VST1d64T_UPD:
1783     case ARM::VST1d8Q:
1784     case ARM::VST1d16Q:
1785     case ARM::VST1d32Q:
1786     case ARM::VST1d64Q:
1787     case ARM::VST1d8Q_UPD:
1788     case ARM::VST1d16Q_UPD:
1789     case ARM::VST1d32Q_UPD:
1790     case ARM::VST1d64Q_UPD:
1791     case ARM::VST2d8:
1792     case ARM::VST2d16:
1793     case ARM::VST2d32:
1794     case ARM::VST2d8_UPD:
1795     case ARM::VST2d16_UPD:
1796     case ARM::VST2d32_UPD:
1797     case ARM::VST2q8:
1798     case ARM::VST2q16:
1799     case ARM::VST2q32:
1800     case ARM::VST2q8_UPD:
1801     case ARM::VST2q16_UPD:
1802     case ARM::VST2q32_UPD:
1803     case ARM::VST3d8:
1804     case ARM::VST3d16:
1805     case ARM::VST3d32:
1806     case ARM::VST3d8_UPD:
1807     case ARM::VST3d16_UPD:
1808     case ARM::VST3d32_UPD:
1809     case ARM::VST4d8:
1810     case ARM::VST4d16:
1811     case ARM::VST4d32:
1812     case ARM::VST4d8_UPD:
1813     case ARM::VST4d16_UPD:
1814     case ARM::VST4d32_UPD:
1815       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder));
1816       break;
1817     case ARM::VST2b8:
1818     case ARM::VST2b16:
1819     case ARM::VST2b32:
1820     case ARM::VST2b8_UPD:
1821     case ARM::VST2b16_UPD:
1822     case ARM::VST2b32_UPD:
1823     case ARM::VST3q8:
1824     case ARM::VST3q16:
1825     case ARM::VST3q32:
1826     case ARM::VST3q8_UPD:
1827     case ARM::VST3q16_UPD:
1828     case ARM::VST3q32_UPD:
1829     case ARM::VST4q8:
1830     case ARM::VST4q16:
1831     case ARM::VST4q32:
1832     case ARM::VST4q8_UPD:
1833     case ARM::VST4q16_UPD:
1834     case ARM::VST4q32_UPD:
1835       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder));
1836       break;
1837     default:
1838       break;
1839   }
1840 
1841   // Third input register
1842   switch (Inst.getOpcode()) {
1843     case ARM::VST1d8T:
1844     case ARM::VST1d16T:
1845     case ARM::VST1d32T:
1846     case ARM::VST1d64T:
1847     case ARM::VST1d8T_UPD:
1848     case ARM::VST1d16T_UPD:
1849     case ARM::VST1d32T_UPD:
1850     case ARM::VST1d64T_UPD:
1851     case ARM::VST1d8Q:
1852     case ARM::VST1d16Q:
1853     case ARM::VST1d32Q:
1854     case ARM::VST1d64Q:
1855     case ARM::VST1d8Q_UPD:
1856     case ARM::VST1d16Q_UPD:
1857     case ARM::VST1d32Q_UPD:
1858     case ARM::VST1d64Q_UPD:
1859     case ARM::VST2q8:
1860     case ARM::VST2q16:
1861     case ARM::VST2q32:
1862     case ARM::VST2q8_UPD:
1863     case ARM::VST2q16_UPD:
1864     case ARM::VST2q32_UPD:
1865     case ARM::VST3d8:
1866     case ARM::VST3d16:
1867     case ARM::VST3d32:
1868     case ARM::VST3d8_UPD:
1869     case ARM::VST3d16_UPD:
1870     case ARM::VST3d32_UPD:
1871     case ARM::VST4d8:
1872     case ARM::VST4d16:
1873     case ARM::VST4d32:
1874     case ARM::VST4d8_UPD:
1875     case ARM::VST4d16_UPD:
1876     case ARM::VST4d32_UPD:
1877       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder));
1878       break;
1879     case ARM::VST3q8:
1880     case ARM::VST3q16:
1881     case ARM::VST3q32:
1882     case ARM::VST3q8_UPD:
1883     case ARM::VST3q16_UPD:
1884     case ARM::VST3q32_UPD:
1885     case ARM::VST4q8:
1886     case ARM::VST4q16:
1887     case ARM::VST4q32:
1888     case ARM::VST4q8_UPD:
1889     case ARM::VST4q16_UPD:
1890     case ARM::VST4q32_UPD:
1891       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder));
1892       break;
1893     default:
1894       break;
1895   }
1896 
1897   // Fourth input register
1898   switch (Inst.getOpcode()) {
1899     case ARM::VST1d8Q:
1900     case ARM::VST1d16Q:
1901     case ARM::VST1d32Q:
1902     case ARM::VST1d64Q:
1903     case ARM::VST1d8Q_UPD:
1904     case ARM::VST1d16Q_UPD:
1905     case ARM::VST1d32Q_UPD:
1906     case ARM::VST1d64Q_UPD:
1907     case ARM::VST2q8:
1908     case ARM::VST2q16:
1909     case ARM::VST2q32:
1910     case ARM::VST2q8_UPD:
1911     case ARM::VST2q16_UPD:
1912     case ARM::VST2q32_UPD:
1913     case ARM::VST4d8:
1914     case ARM::VST4d16:
1915     case ARM::VST4d32:
1916     case ARM::VST4d8_UPD:
1917     case ARM::VST4d16_UPD:
1918     case ARM::VST4d32_UPD:
1919       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder));
1920       break;
1921     case ARM::VST4q8:
1922     case ARM::VST4q16:
1923     case ARM::VST4q32:
1924     case ARM::VST4q8_UPD:
1925     case ARM::VST4q16_UPD:
1926     case ARM::VST4q32_UPD:
1927       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder));
1928       break;
1929     default:
1930       break;
1931   }
1932 
1933   return S;
1934 }
1935 
1936 static DecodeStatus DecodeVLD1DupInstruction(llvm::MCInst &Inst, unsigned Insn,
1937                                     uint64_t Address, const void *Decoder) {
1938   DecodeStatus S = Success;
1939 
1940   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1941   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1942   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1943   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1944   unsigned align = fieldFromInstruction32(Insn, 4, 1);
1945   unsigned size = fieldFromInstruction32(Insn, 6, 2);
1946   unsigned regs = fieldFromInstruction32(Insn, 5, 1) + 1;
1947 
1948   align *= (1 << size);
1949 
1950   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
1951   if (regs == 2) {
1952     CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder));
1953   }
1954   if (Rm == 0xD) {
1955     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1956   }
1957 
1958   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1959   Inst.addOperand(MCOperand::CreateImm(align));
1960 
1961   if (Rm == 0xD)
1962     Inst.addOperand(MCOperand::CreateReg(0));
1963   else if (Rm != 0xF) {
1964     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
1965   }
1966 
1967   return S;
1968 }
1969 
1970 static DecodeStatus DecodeVLD2DupInstruction(llvm::MCInst &Inst, unsigned Insn,
1971                                     uint64_t Address, const void *Decoder) {
1972   DecodeStatus S = Success;
1973 
1974   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1975   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1976   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1977   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1978   unsigned align = fieldFromInstruction32(Insn, 4, 1);
1979   unsigned size = 1 << fieldFromInstruction32(Insn, 6, 2);
1980   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
1981   align *= 2*size;
1982 
1983   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
1984   CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder));
1985   if (Rm == 0xD) {
1986     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1987   }
1988 
1989   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1990   Inst.addOperand(MCOperand::CreateImm(align));
1991 
1992   if (Rm == 0xD)
1993     Inst.addOperand(MCOperand::CreateReg(0));
1994   else if (Rm != 0xF) {
1995     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
1996   }
1997 
1998   return S;
1999 }
2000 
2001 static DecodeStatus DecodeVLD3DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2002                                     uint64_t Address, const void *Decoder) {
2003   DecodeStatus S = Success;
2004 
2005   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2006   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2007   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2008   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2009   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2010 
2011   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2012   CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder));
2013   CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder));
2014   if (Rm == 0xD) {
2015     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2016   }
2017 
2018   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2019   Inst.addOperand(MCOperand::CreateImm(0));
2020 
2021   if (Rm == 0xD)
2022     Inst.addOperand(MCOperand::CreateReg(0));
2023   else if (Rm != 0xF) {
2024     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
2025   }
2026 
2027   return S;
2028 }
2029 
2030 static DecodeStatus DecodeVLD4DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2031                                     uint64_t Address, const void *Decoder) {
2032   DecodeStatus S = Success;
2033 
2034   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2035   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2036   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2037   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2038   unsigned size = fieldFromInstruction32(Insn, 6, 2);
2039   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2040   unsigned align = fieldFromInstruction32(Insn, 4, 1);
2041 
2042   if (size == 0x3) {
2043     size = 4;
2044     align = 16;
2045   } else {
2046     if (size == 2) {
2047       size = 1 << size;
2048       align *= 8;
2049     } else {
2050       size = 1 << size;
2051       align *= 4*size;
2052     }
2053   }
2054 
2055   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2056   CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder));
2057   CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder));
2058   CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder));
2059   if (Rm == 0xD) {
2060     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2061   }
2062 
2063   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2064   Inst.addOperand(MCOperand::CreateImm(align));
2065 
2066   if (Rm == 0xD)
2067     Inst.addOperand(MCOperand::CreateReg(0));
2068   else if (Rm != 0xF) {
2069     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
2070   }
2071 
2072   return S;
2073 }
2074 
2075 static DecodeStatus
2076 DecodeNEONModImmInstruction(llvm::MCInst &Inst, unsigned Insn,
2077                             uint64_t Address, const void *Decoder) {
2078   DecodeStatus S = Success;
2079 
2080   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2081   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2082   unsigned imm = fieldFromInstruction32(Insn, 0, 4);
2083   imm |= fieldFromInstruction32(Insn, 16, 3) << 4;
2084   imm |= fieldFromInstruction32(Insn, 24, 1) << 7;
2085   imm |= fieldFromInstruction32(Insn, 8, 4) << 8;
2086   imm |= fieldFromInstruction32(Insn, 5, 1) << 12;
2087   unsigned Q = fieldFromInstruction32(Insn, 6, 1);
2088 
2089   if (Q) {
2090     CHECK(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder));
2091   } else {
2092     CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2093   }
2094 
2095   Inst.addOperand(MCOperand::CreateImm(imm));
2096 
2097   switch (Inst.getOpcode()) {
2098     case ARM::VORRiv4i16:
2099     case ARM::VORRiv2i32:
2100     case ARM::VBICiv4i16:
2101     case ARM::VBICiv2i32:
2102       CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2103       break;
2104     case ARM::VORRiv8i16:
2105     case ARM::VORRiv4i32:
2106     case ARM::VBICiv8i16:
2107     case ARM::VBICiv4i32:
2108       CHECK(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder));
2109       break;
2110     default:
2111       break;
2112   }
2113 
2114   return S;
2115 }
2116 
2117 static DecodeStatus DecodeVSHLMaxInstruction(llvm::MCInst &Inst, unsigned Insn,
2118                                         uint64_t Address, const void *Decoder) {
2119   DecodeStatus S = Success;
2120 
2121   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2122   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2123   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2124   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2125   unsigned size = fieldFromInstruction32(Insn, 18, 2);
2126 
2127   CHECK(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder));
2128   CHECK(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder));
2129   Inst.addOperand(MCOperand::CreateImm(8 << size));
2130 
2131   return S;
2132 }
2133 
2134 static DecodeStatus DecodeShiftRight8Imm(llvm::MCInst &Inst, unsigned Val,
2135                                uint64_t Address, const void *Decoder) {
2136   Inst.addOperand(MCOperand::CreateImm(8 - Val));
2137   return Success;
2138 }
2139 
2140 static DecodeStatus DecodeShiftRight16Imm(llvm::MCInst &Inst, unsigned Val,
2141                                uint64_t Address, const void *Decoder) {
2142   Inst.addOperand(MCOperand::CreateImm(16 - Val));
2143   return Success;
2144 }
2145 
2146 static DecodeStatus DecodeShiftRight32Imm(llvm::MCInst &Inst, unsigned Val,
2147                                uint64_t Address, const void *Decoder) {
2148   Inst.addOperand(MCOperand::CreateImm(32 - Val));
2149   return Success;
2150 }
2151 
2152 static DecodeStatus DecodeShiftRight64Imm(llvm::MCInst &Inst, unsigned Val,
2153                                uint64_t Address, const void *Decoder) {
2154   Inst.addOperand(MCOperand::CreateImm(64 - Val));
2155   return Success;
2156 }
2157 
2158 static DecodeStatus DecodeTBLInstruction(llvm::MCInst &Inst, unsigned Insn,
2159                                uint64_t Address, const void *Decoder) {
2160   DecodeStatus S = Success;
2161 
2162   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2163   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2164   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2165   Rn |= fieldFromInstruction32(Insn, 7, 1) << 4;
2166   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2167   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2168   unsigned op = fieldFromInstruction32(Insn, 6, 1);
2169   unsigned length = fieldFromInstruction32(Insn, 8, 2) + 1;
2170 
2171   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2172   if (op) {
2173     CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)); // Writeback
2174   }
2175 
2176   for (unsigned i = 0; i < length; ++i) {
2177     CHECK(S, DecodeDPRRegisterClass(Inst, (Rn+i)%32, Address, Decoder));
2178   }
2179 
2180   CHECK(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder));
2181 
2182   return S;
2183 }
2184 
2185 static DecodeStatus DecodeVFPfpImm(llvm::MCInst &Inst, unsigned Val,
2186                             uint64_t Address, const void *Decoder) {
2187   // The immediate needs to be a fully instantiated float.  However, the
2188   // auto-generated decoder is only able to fill in some of the bits
2189   // necessary.  For instance, the 'b' bit is replicated multiple times,
2190   // and is even present in inverted form in one bit.  We do a little
2191   // binary parsing here to fill in those missing bits, and then
2192   // reinterpret it all as a float.
2193   union {
2194     uint32_t integer;
2195     float fp;
2196   } fp_conv;
2197 
2198   fp_conv.integer = Val;
2199   uint32_t b = fieldFromInstruction32(Val, 25, 1);
2200   fp_conv.integer |= b << 26;
2201   fp_conv.integer |= b << 27;
2202   fp_conv.integer |= b << 28;
2203   fp_conv.integer |= b << 29;
2204   fp_conv.integer |= (~b & 0x1) << 30;
2205 
2206   Inst.addOperand(MCOperand::CreateFPImm(fp_conv.fp));
2207   return Success;
2208 }
2209 
2210 static DecodeStatus DecodeThumbAddSpecialReg(llvm::MCInst &Inst, uint16_t Insn,
2211                                      uint64_t Address, const void *Decoder) {
2212   DecodeStatus S = Success;
2213 
2214   unsigned dst = fieldFromInstruction16(Insn, 8, 3);
2215   unsigned imm = fieldFromInstruction16(Insn, 0, 8);
2216 
2217   CHECK(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder));
2218 
2219   if (Inst.getOpcode() == ARM::tADR)
2220     Inst.addOperand(MCOperand::CreateReg(ARM::PC));
2221   else if (Inst.getOpcode() == ARM::tADDrSPi)
2222     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2223   else
2224     return Fail;
2225 
2226   Inst.addOperand(MCOperand::CreateImm(imm));
2227   return S;
2228 }
2229 
2230 static DecodeStatus DecodeThumbBROperand(llvm::MCInst &Inst, unsigned Val,
2231                                  uint64_t Address, const void *Decoder) {
2232   Inst.addOperand(MCOperand::CreateImm(SignExtend32<12>(Val << 1)));
2233   return Success;
2234 }
2235 
2236 static DecodeStatus DecodeT2BROperand(llvm::MCInst &Inst, unsigned Val,
2237                                  uint64_t Address, const void *Decoder) {
2238   Inst.addOperand(MCOperand::CreateImm(SignExtend32<21>(Val)));
2239   return Success;
2240 }
2241 
2242 static DecodeStatus DecodeThumbCmpBROperand(llvm::MCInst &Inst, unsigned Val,
2243                                  uint64_t Address, const void *Decoder) {
2244   Inst.addOperand(MCOperand::CreateImm(SignExtend32<7>(Val << 1)));
2245   return Success;
2246 }
2247 
2248 static DecodeStatus DecodeThumbAddrModeRR(llvm::MCInst &Inst, unsigned Val,
2249                                  uint64_t Address, const void *Decoder) {
2250   DecodeStatus S = Success;
2251 
2252   unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2253   unsigned Rm = fieldFromInstruction32(Val, 3, 3);
2254 
2255   CHECK(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder));
2256   CHECK(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder));
2257 
2258   return S;
2259 }
2260 
2261 static DecodeStatus DecodeThumbAddrModeIS(llvm::MCInst &Inst, unsigned Val,
2262                                   uint64_t Address, const void *Decoder) {
2263   DecodeStatus S = Success;
2264 
2265   unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2266   unsigned imm = fieldFromInstruction32(Val, 3, 5);
2267 
2268   CHECK(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder));
2269   Inst.addOperand(MCOperand::CreateImm(imm));
2270 
2271   return S;
2272 }
2273 
2274 static DecodeStatus DecodeThumbAddrModePC(llvm::MCInst &Inst, unsigned Val,
2275                                   uint64_t Address, const void *Decoder) {
2276   Inst.addOperand(MCOperand::CreateImm(Val << 2));
2277 
2278   return Success;
2279 }
2280 
2281 static DecodeStatus DecodeThumbAddrModeSP(llvm::MCInst &Inst, unsigned Val,
2282                                   uint64_t Address, const void *Decoder) {
2283   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2284   Inst.addOperand(MCOperand::CreateImm(Val << 2));
2285 
2286   return Success;
2287 }
2288 
2289 static DecodeStatus DecodeT2AddrModeSOReg(llvm::MCInst &Inst, unsigned Val,
2290                                   uint64_t Address, const void *Decoder) {
2291   DecodeStatus S = Success;
2292 
2293   unsigned Rn = fieldFromInstruction32(Val, 6, 4);
2294   unsigned Rm = fieldFromInstruction32(Val, 2, 4);
2295   unsigned imm = fieldFromInstruction32(Val, 0, 2);
2296 
2297   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2298   CHECK(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder));
2299   Inst.addOperand(MCOperand::CreateImm(imm));
2300 
2301   return S;
2302 }
2303 
2304 static DecodeStatus DecodeT2LoadShift(llvm::MCInst &Inst, unsigned Insn,
2305                               uint64_t Address, const void *Decoder) {
2306   DecodeStatus S = Success;
2307 
2308   if (Inst.getOpcode() != ARM::t2PLDs) {
2309     unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2310     CHECK(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
2311   }
2312 
2313   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2314   if (Rn == 0xF) {
2315     switch (Inst.getOpcode()) {
2316       case ARM::t2LDRBs:
2317         Inst.setOpcode(ARM::t2LDRBpci);
2318         break;
2319       case ARM::t2LDRHs:
2320         Inst.setOpcode(ARM::t2LDRHpci);
2321         break;
2322       case ARM::t2LDRSHs:
2323         Inst.setOpcode(ARM::t2LDRSHpci);
2324         break;
2325       case ARM::t2LDRSBs:
2326         Inst.setOpcode(ARM::t2LDRSBpci);
2327         break;
2328       case ARM::t2PLDs:
2329         Inst.setOpcode(ARM::t2PLDi12);
2330         Inst.addOperand(MCOperand::CreateReg(ARM::PC));
2331         break;
2332       default:
2333         return Fail;
2334     }
2335 
2336     int imm = fieldFromInstruction32(Insn, 0, 12);
2337     if (!fieldFromInstruction32(Insn, 23, 1)) imm *= -1;
2338     Inst.addOperand(MCOperand::CreateImm(imm));
2339 
2340     return S;
2341   }
2342 
2343   unsigned addrmode = fieldFromInstruction32(Insn, 4, 2);
2344   addrmode |= fieldFromInstruction32(Insn, 0, 4) << 2;
2345   addrmode |= fieldFromInstruction32(Insn, 16, 4) << 6;
2346   CHECK(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder));
2347 
2348   return S;
2349 }
2350 
2351 static DecodeStatus DecodeT2Imm8S4(llvm::MCInst &Inst, unsigned Val,
2352                            uint64_t Address, const void *Decoder) {
2353   int imm = Val & 0xFF;
2354   if (!(Val & 0x100)) imm *= -1;
2355   Inst.addOperand(MCOperand::CreateImm(imm << 2));
2356 
2357   return Success;
2358 }
2359 
2360 static DecodeStatus DecodeT2AddrModeImm8s4(llvm::MCInst &Inst, unsigned Val,
2361                                    uint64_t Address, const void *Decoder) {
2362   DecodeStatus S = Success;
2363 
2364   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2365   unsigned imm = fieldFromInstruction32(Val, 0, 9);
2366 
2367   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2368   CHECK(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder));
2369 
2370   return S;
2371 }
2372 
2373 static DecodeStatus DecodeT2Imm8(llvm::MCInst &Inst, unsigned Val,
2374                          uint64_t Address, const void *Decoder) {
2375   int imm = Val & 0xFF;
2376   if (!(Val & 0x100)) imm *= -1;
2377   Inst.addOperand(MCOperand::CreateImm(imm));
2378 
2379   return Success;
2380 }
2381 
2382 
2383 static DecodeStatus DecodeT2AddrModeImm8(llvm::MCInst &Inst, unsigned Val,
2384                                  uint64_t Address, const void *Decoder) {
2385   DecodeStatus S = Success;
2386 
2387   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2388   unsigned imm = fieldFromInstruction32(Val, 0, 9);
2389 
2390   // Some instructions always use an additive offset.
2391   switch (Inst.getOpcode()) {
2392     case ARM::t2LDRT:
2393     case ARM::t2LDRBT:
2394     case ARM::t2LDRHT:
2395     case ARM::t2LDRSBT:
2396     case ARM::t2LDRSHT:
2397       imm |= 0x100;
2398       break;
2399     default:
2400       break;
2401   }
2402 
2403   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2404   CHECK(S, DecodeT2Imm8(Inst, imm, Address, Decoder));
2405 
2406   return S;
2407 }
2408 
2409 
2410 static DecodeStatus DecodeT2AddrModeImm12(llvm::MCInst &Inst, unsigned Val,
2411                                   uint64_t Address, const void *Decoder) {
2412   DecodeStatus S = Success;
2413 
2414   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
2415   unsigned imm = fieldFromInstruction32(Val, 0, 12);
2416 
2417   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2418   Inst.addOperand(MCOperand::CreateImm(imm));
2419 
2420   return S;
2421 }
2422 
2423 
2424 static DecodeStatus DecodeThumbAddSPImm(llvm::MCInst &Inst, uint16_t Insn,
2425                                 uint64_t Address, const void *Decoder) {
2426   unsigned imm = fieldFromInstruction16(Insn, 0, 7);
2427 
2428   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2429   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2430   Inst.addOperand(MCOperand::CreateImm(imm));
2431 
2432   return Success;
2433 }
2434 
2435 static DecodeStatus DecodeThumbAddSPReg(llvm::MCInst &Inst, uint16_t Insn,
2436                                 uint64_t Address, const void *Decoder) {
2437   DecodeStatus S = Success;
2438 
2439   if (Inst.getOpcode() == ARM::tADDrSP) {
2440     unsigned Rdm = fieldFromInstruction16(Insn, 0, 3);
2441     Rdm |= fieldFromInstruction16(Insn, 7, 1) << 3;
2442 
2443     CHECK(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder));
2444     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2445     CHECK(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder));
2446   } else if (Inst.getOpcode() == ARM::tADDspr) {
2447     unsigned Rm = fieldFromInstruction16(Insn, 3, 4);
2448 
2449     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2450     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2451     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
2452   }
2453 
2454   return S;
2455 }
2456 
2457 static DecodeStatus DecodeThumbCPS(llvm::MCInst &Inst, uint16_t Insn,
2458                            uint64_t Address, const void *Decoder) {
2459   unsigned imod = fieldFromInstruction16(Insn, 4, 1) | 0x2;
2460   unsigned flags = fieldFromInstruction16(Insn, 0, 3);
2461 
2462   Inst.addOperand(MCOperand::CreateImm(imod));
2463   Inst.addOperand(MCOperand::CreateImm(flags));
2464 
2465   return Success;
2466 }
2467 
2468 static DecodeStatus DecodePostIdxReg(llvm::MCInst &Inst, unsigned Insn,
2469                              uint64_t Address, const void *Decoder) {
2470   DecodeStatus S = Success;
2471   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2472   unsigned add = fieldFromInstruction32(Insn, 4, 1);
2473 
2474   CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) ;
2475   Inst.addOperand(MCOperand::CreateImm(add));
2476 
2477   return S;
2478 }
2479 
2480 static DecodeStatus DecodeThumbBLXOffset(llvm::MCInst &Inst, unsigned Val,
2481                                  uint64_t Address, const void *Decoder) {
2482   Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
2483   return Success;
2484 }
2485 
2486 static DecodeStatus DecodeCoprocessor(llvm::MCInst &Inst, unsigned Val,
2487                               uint64_t Address, const void *Decoder) {
2488   if (Val == 0xA || Val == 0xB)
2489     return Fail;
2490 
2491   Inst.addOperand(MCOperand::CreateImm(Val));
2492   return Success;
2493 }
2494 
2495 static DecodeStatus
2496 DecodeThumb2BCCInstruction(llvm::MCInst &Inst, unsigned Insn,
2497                            uint64_t Address, const void *Decoder) {
2498   DecodeStatus S = Success;
2499 
2500   unsigned pred = fieldFromInstruction32(Insn, 22, 4);
2501   if (pred == 0xE || pred == 0xF) {
2502     unsigned opc = fieldFromInstruction32(Insn, 4, 2);
2503     switch (opc) {
2504       default:
2505         return Fail;
2506       case 0:
2507         Inst.setOpcode(ARM::t2DSB);
2508         break;
2509       case 1:
2510         Inst.setOpcode(ARM::t2DMB);
2511         break;
2512       case 2:
2513         Inst.setOpcode(ARM::t2ISB);
2514         return Success;
2515     }
2516 
2517     unsigned imm = fieldFromInstruction32(Insn, 0, 4);
2518     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
2519   }
2520 
2521   unsigned brtarget = fieldFromInstruction32(Insn, 0, 11) << 1;
2522   brtarget |= fieldFromInstruction32(Insn, 11, 1) << 19;
2523   brtarget |= fieldFromInstruction32(Insn, 13, 1) << 18;
2524   brtarget |= fieldFromInstruction32(Insn, 16, 6) << 12;
2525   brtarget |= fieldFromInstruction32(Insn, 26, 1) << 20;
2526 
2527   CHECK(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder));
2528   CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
2529 
2530   return S;
2531 }
2532 
2533 // Decode a shifted immediate operand.  These basically consist
2534 // of an 8-bit value, and a 4-bit directive that specifies either
2535 // a splat operation or a rotation.
2536 static DecodeStatus DecodeT2SOImm(llvm::MCInst &Inst, unsigned Val,
2537                           uint64_t Address, const void *Decoder) {
2538   unsigned ctrl = fieldFromInstruction32(Val, 10, 2);
2539   if (ctrl == 0) {
2540     unsigned byte = fieldFromInstruction32(Val, 8, 2);
2541     unsigned imm = fieldFromInstruction32(Val, 0, 8);
2542     switch (byte) {
2543       case 0:
2544         Inst.addOperand(MCOperand::CreateImm(imm));
2545         break;
2546       case 1:
2547         Inst.addOperand(MCOperand::CreateImm((imm << 16) | imm));
2548         break;
2549       case 2:
2550         Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 8)));
2551         break;
2552       case 3:
2553         Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 16) |
2554                                              (imm << 8)  |  imm));
2555         break;
2556     }
2557   } else {
2558     unsigned unrot = fieldFromInstruction32(Val, 0, 7) | 0x80;
2559     unsigned rot = fieldFromInstruction32(Val, 7, 5);
2560     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
2561     Inst.addOperand(MCOperand::CreateImm(imm));
2562   }
2563 
2564   return Success;
2565 }
2566 
2567 static DecodeStatus
2568 DecodeThumbBCCTargetOperand(llvm::MCInst &Inst, unsigned Val,
2569                             uint64_t Address, const void *Decoder){
2570   Inst.addOperand(MCOperand::CreateImm(Val << 1));
2571   return Success;
2572 }
2573 
2574 static DecodeStatus DecodeThumbBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
2575                                        uint64_t Address, const void *Decoder){
2576   Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
2577   return Success;
2578 }
2579 
2580 static DecodeStatus DecodeMemBarrierOption(llvm::MCInst &Inst, unsigned Val,
2581                                    uint64_t Address, const void *Decoder) {
2582   switch (Val) {
2583   default:
2584     return Fail;
2585   case 0xF: // SY
2586   case 0xE: // ST
2587   case 0xB: // ISH
2588   case 0xA: // ISHST
2589   case 0x7: // NSH
2590   case 0x6: // NSHST
2591   case 0x3: // OSH
2592   case 0x2: // OSHST
2593     break;
2594   }
2595 
2596   Inst.addOperand(MCOperand::CreateImm(Val));
2597   return Success;
2598 }
2599 
2600 static DecodeStatus DecodeMSRMask(llvm::MCInst &Inst, unsigned Val,
2601                           uint64_t Address, const void *Decoder) {
2602   if (!Val) return Fail;
2603   Inst.addOperand(MCOperand::CreateImm(Val));
2604   return Success;
2605 }
2606 
2607 static DecodeStatus DecodeDoubleRegLoad(llvm::MCInst &Inst, unsigned Insn,
2608                                         uint64_t Address, const void *Decoder) {
2609   DecodeStatus S = Success;
2610 
2611   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2612   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2613   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
2614 
2615   if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return Fail;
2616 
2617   CHECK(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
2618   CHECK(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder));
2619   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2620   CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
2621 
2622   return S;
2623 }
2624 
2625 
2626 static DecodeStatus DecodeDoubleRegStore(llvm::MCInst &Inst, unsigned Insn,
2627                                          uint64_t Address, const void *Decoder){
2628   DecodeStatus S = Success;
2629 
2630   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2631   unsigned Rt = fieldFromInstruction32(Insn, 0, 4);
2632   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2633   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
2634 
2635   CHECK(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder));
2636 
2637   if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return Fail;
2638   if (Rd == Rn || Rd == Rt || Rd == Rt+1) return Fail;
2639 
2640   CHECK(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
2641   CHECK(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder));
2642   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2643   CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
2644 
2645   return S;
2646 }
2647 
2648 static DecodeStatus DecodeSTRPreImm(llvm::MCInst &Inst, unsigned Insn,
2649                             uint64_t Address, const void *Decoder) {
2650   DecodeStatus S = Success;
2651 
2652   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2653   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2654   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
2655   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
2656   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
2657   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
2658 
2659   if (Rn == 0xF || Rn == Rt) CHECK(S, Unpredictable);
2660 
2661   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2662   CHECK(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
2663   CHECK(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder));
2664   CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
2665 
2666   return S;
2667 }
2668 
2669 static DecodeStatus DecodeSTRPreReg(llvm::MCInst &Inst, unsigned Insn,
2670                             uint64_t Address, const void *Decoder) {
2671   DecodeStatus S = Success;
2672 
2673   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2674   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2675   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
2676   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
2677   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
2678   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
2679 
2680   if (Rn == 0xF || Rn == Rt) CHECK(S, Unpredictable);
2681 
2682   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2683   CHECK(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
2684   CHECK(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder));
2685   CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
2686 
2687   return S;
2688 }
2689 
2690 static DecodeStatus DecodeVLD1LN(llvm::MCInst &Inst, unsigned Insn,
2691                          uint64_t Address, const void *Decoder) {
2692   DecodeStatus S = Success;
2693 
2694   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2695   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2696   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2697   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2698   unsigned size = fieldFromInstruction32(Insn, 10, 2);
2699 
2700   unsigned align = 0;
2701   unsigned index = 0;
2702   switch (size) {
2703     default:
2704       return Fail;
2705     case 0:
2706       if (fieldFromInstruction32(Insn, 4, 1))
2707         return Fail; // UNDEFINED
2708       index = fieldFromInstruction32(Insn, 5, 3);
2709       break;
2710     case 1:
2711       if (fieldFromInstruction32(Insn, 5, 1))
2712         return Fail; // UNDEFINED
2713       index = fieldFromInstruction32(Insn, 6, 2);
2714       if (fieldFromInstruction32(Insn, 4, 1))
2715         align = 2;
2716       break;
2717     case 2:
2718       if (fieldFromInstruction32(Insn, 6, 1))
2719         return Fail; // UNDEFINED
2720       index = fieldFromInstruction32(Insn, 7, 1);
2721       if (fieldFromInstruction32(Insn, 4, 2) != 0)
2722         align = 4;
2723   }
2724 
2725   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2726   if (Rm != 0xF) { // Writeback
2727     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2728   }
2729   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2730   Inst.addOperand(MCOperand::CreateImm(align));
2731   if (Rm != 0xF && Rm != 0xD) {
2732     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
2733   }
2734 
2735   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2736   Inst.addOperand(MCOperand::CreateImm(index));
2737 
2738   return S;
2739 }
2740 
2741 static DecodeStatus DecodeVST1LN(llvm::MCInst &Inst, unsigned Insn,
2742                          uint64_t Address, const void *Decoder) {
2743   DecodeStatus S = Success;
2744 
2745   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2746   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2747   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2748   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2749   unsigned size = fieldFromInstruction32(Insn, 10, 2);
2750 
2751   unsigned align = 0;
2752   unsigned index = 0;
2753   switch (size) {
2754     default:
2755       return Fail;
2756     case 0:
2757       if (fieldFromInstruction32(Insn, 4, 1))
2758         return Fail; // UNDEFINED
2759       index = fieldFromInstruction32(Insn, 5, 3);
2760       break;
2761     case 1:
2762       if (fieldFromInstruction32(Insn, 5, 1))
2763         return Fail; // UNDEFINED
2764       index = fieldFromInstruction32(Insn, 6, 2);
2765       if (fieldFromInstruction32(Insn, 4, 1))
2766         align = 2;
2767       break;
2768     case 2:
2769       if (fieldFromInstruction32(Insn, 6, 1))
2770         return Fail; // UNDEFINED
2771       index = fieldFromInstruction32(Insn, 7, 1);
2772       if (fieldFromInstruction32(Insn, 4, 2) != 0)
2773         align = 4;
2774   }
2775 
2776   if (Rm != 0xF) { // Writeback
2777     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2778   }
2779   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2780   Inst.addOperand(MCOperand::CreateImm(align));
2781   if (Rm != 0xF && Rm != 0xD) {
2782     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
2783   }
2784 
2785   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2786   Inst.addOperand(MCOperand::CreateImm(index));
2787 
2788   return S;
2789 }
2790 
2791 
2792 static DecodeStatus DecodeVLD2LN(llvm::MCInst &Inst, unsigned Insn,
2793                          uint64_t Address, const void *Decoder) {
2794   DecodeStatus S = Success;
2795 
2796   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2797   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2798   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2799   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2800   unsigned size = fieldFromInstruction32(Insn, 10, 2);
2801 
2802   unsigned align = 0;
2803   unsigned index = 0;
2804   unsigned inc = 1;
2805   switch (size) {
2806     default:
2807       return Fail;
2808     case 0:
2809       index = fieldFromInstruction32(Insn, 5, 3);
2810       if (fieldFromInstruction32(Insn, 4, 1))
2811         align = 2;
2812       break;
2813     case 1:
2814       index = fieldFromInstruction32(Insn, 6, 2);
2815       if (fieldFromInstruction32(Insn, 4, 1))
2816         align = 4;
2817       if (fieldFromInstruction32(Insn, 5, 1))
2818         inc = 2;
2819       break;
2820     case 2:
2821       if (fieldFromInstruction32(Insn, 5, 1))
2822         return Fail; // UNDEFINED
2823       index = fieldFromInstruction32(Insn, 7, 1);
2824       if (fieldFromInstruction32(Insn, 4, 1) != 0)
2825         align = 8;
2826       if (fieldFromInstruction32(Insn, 6, 1))
2827         inc = 2;
2828       break;
2829   }
2830 
2831   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2832   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
2833   if (Rm != 0xF) { // Writeback
2834     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2835   }
2836   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2837   Inst.addOperand(MCOperand::CreateImm(align));
2838   if (Rm != 0xF && Rm != 0xD) {
2839     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
2840   }
2841 
2842   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2843   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
2844   Inst.addOperand(MCOperand::CreateImm(index));
2845 
2846   return S;
2847 }
2848 
2849 static DecodeStatus DecodeVST2LN(llvm::MCInst &Inst, unsigned Insn,
2850                          uint64_t Address, const void *Decoder) {
2851   DecodeStatus S = Success;
2852 
2853   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2854   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2855   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2856   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2857   unsigned size = fieldFromInstruction32(Insn, 10, 2);
2858 
2859   unsigned align = 0;
2860   unsigned index = 0;
2861   unsigned inc = 1;
2862   switch (size) {
2863     default:
2864       return Fail;
2865     case 0:
2866       index = fieldFromInstruction32(Insn, 5, 3);
2867       if (fieldFromInstruction32(Insn, 4, 1))
2868         align = 2;
2869       break;
2870     case 1:
2871       index = fieldFromInstruction32(Insn, 6, 2);
2872       if (fieldFromInstruction32(Insn, 4, 1))
2873         align = 4;
2874       if (fieldFromInstruction32(Insn, 5, 1))
2875         inc = 2;
2876       break;
2877     case 2:
2878       if (fieldFromInstruction32(Insn, 5, 1))
2879         return Fail; // UNDEFINED
2880       index = fieldFromInstruction32(Insn, 7, 1);
2881       if (fieldFromInstruction32(Insn, 4, 1) != 0)
2882         align = 8;
2883       if (fieldFromInstruction32(Insn, 6, 1))
2884         inc = 2;
2885       break;
2886   }
2887 
2888   if (Rm != 0xF) { // Writeback
2889     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2890   }
2891   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2892   Inst.addOperand(MCOperand::CreateImm(align));
2893   if (Rm != 0xF && Rm != 0xD) {
2894     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
2895   }
2896 
2897   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2898   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
2899   Inst.addOperand(MCOperand::CreateImm(index));
2900 
2901   return S;
2902 }
2903 
2904 
2905 static DecodeStatus DecodeVLD3LN(llvm::MCInst &Inst, unsigned Insn,
2906                          uint64_t Address, const void *Decoder) {
2907   DecodeStatus S = Success;
2908 
2909   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2910   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2911   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2912   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2913   unsigned size = fieldFromInstruction32(Insn, 10, 2);
2914 
2915   unsigned align = 0;
2916   unsigned index = 0;
2917   unsigned inc = 1;
2918   switch (size) {
2919     default:
2920       return Fail;
2921     case 0:
2922       if (fieldFromInstruction32(Insn, 4, 1))
2923         return Fail; // UNDEFINED
2924       index = fieldFromInstruction32(Insn, 5, 3);
2925       break;
2926     case 1:
2927       if (fieldFromInstruction32(Insn, 4, 1))
2928         return Fail; // UNDEFINED
2929       index = fieldFromInstruction32(Insn, 6, 2);
2930       if (fieldFromInstruction32(Insn, 5, 1))
2931         inc = 2;
2932       break;
2933     case 2:
2934       if (fieldFromInstruction32(Insn, 4, 2))
2935         return Fail; // UNDEFINED
2936       index = fieldFromInstruction32(Insn, 7, 1);
2937       if (fieldFromInstruction32(Insn, 6, 1))
2938         inc = 2;
2939       break;
2940   }
2941 
2942   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2943   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
2944   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder));
2945 
2946   if (Rm != 0xF) { // Writeback
2947     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2948   }
2949   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2950   Inst.addOperand(MCOperand::CreateImm(align));
2951   if (Rm != 0xF && Rm != 0xD) {
2952     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
2953   }
2954 
2955   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2956   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
2957   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder));
2958   Inst.addOperand(MCOperand::CreateImm(index));
2959 
2960   return S;
2961 }
2962 
2963 static DecodeStatus DecodeVST3LN(llvm::MCInst &Inst, unsigned Insn,
2964                          uint64_t Address, const void *Decoder) {
2965   DecodeStatus S = Success;
2966 
2967   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2968   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2969   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2970   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2971   unsigned size = fieldFromInstruction32(Insn, 10, 2);
2972 
2973   unsigned align = 0;
2974   unsigned index = 0;
2975   unsigned inc = 1;
2976   switch (size) {
2977     default:
2978       return Fail;
2979     case 0:
2980       if (fieldFromInstruction32(Insn, 4, 1))
2981         return Fail; // UNDEFINED
2982       index = fieldFromInstruction32(Insn, 5, 3);
2983       break;
2984     case 1:
2985       if (fieldFromInstruction32(Insn, 4, 1))
2986         return Fail; // UNDEFINED
2987       index = fieldFromInstruction32(Insn, 6, 2);
2988       if (fieldFromInstruction32(Insn, 5, 1))
2989         inc = 2;
2990       break;
2991     case 2:
2992       if (fieldFromInstruction32(Insn, 4, 2))
2993         return Fail; // UNDEFINED
2994       index = fieldFromInstruction32(Insn, 7, 1);
2995       if (fieldFromInstruction32(Insn, 6, 1))
2996         inc = 2;
2997       break;
2998   }
2999 
3000   if (Rm != 0xF) { // Writeback
3001     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
3002   }
3003   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
3004   Inst.addOperand(MCOperand::CreateImm(align));
3005   if (Rm != 0xF && Rm != 0xD) {
3006     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
3007   }
3008 
3009   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
3010   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
3011   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder));
3012   Inst.addOperand(MCOperand::CreateImm(index));
3013 
3014   return S;
3015 }
3016 
3017 
3018 static DecodeStatus DecodeVLD4LN(llvm::MCInst &Inst, unsigned Insn,
3019                          uint64_t Address, const void *Decoder) {
3020   DecodeStatus S = Success;
3021 
3022   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3023   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3024   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3025   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3026   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3027 
3028   unsigned align = 0;
3029   unsigned index = 0;
3030   unsigned inc = 1;
3031   switch (size) {
3032     default:
3033       return Fail;
3034     case 0:
3035       if (fieldFromInstruction32(Insn, 4, 1))
3036         align = 4;
3037       index = fieldFromInstruction32(Insn, 5, 3);
3038       break;
3039     case 1:
3040       if (fieldFromInstruction32(Insn, 4, 1))
3041         align = 8;
3042       index = fieldFromInstruction32(Insn, 6, 2);
3043       if (fieldFromInstruction32(Insn, 5, 1))
3044         inc = 2;
3045       break;
3046     case 2:
3047       if (fieldFromInstruction32(Insn, 4, 2))
3048         align = 4 << fieldFromInstruction32(Insn, 4, 2);
3049       index = fieldFromInstruction32(Insn, 7, 1);
3050       if (fieldFromInstruction32(Insn, 6, 1))
3051         inc = 2;
3052       break;
3053   }
3054 
3055   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
3056   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
3057   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder));
3058   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder));
3059 
3060   if (Rm != 0xF) { // Writeback
3061     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
3062   }
3063   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
3064   Inst.addOperand(MCOperand::CreateImm(align));
3065   if (Rm != 0xF && Rm != 0xD) {
3066     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
3067   }
3068 
3069   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
3070   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
3071   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder));
3072   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder));
3073   Inst.addOperand(MCOperand::CreateImm(index));
3074 
3075   return S;
3076 }
3077 
3078 static DecodeStatus DecodeVST4LN(llvm::MCInst &Inst, unsigned Insn,
3079                          uint64_t Address, const void *Decoder) {
3080   DecodeStatus S = Success;
3081 
3082   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3083   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3084   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3085   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3086   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3087 
3088   unsigned align = 0;
3089   unsigned index = 0;
3090   unsigned inc = 1;
3091   switch (size) {
3092     default:
3093       return Fail;
3094     case 0:
3095       if (fieldFromInstruction32(Insn, 4, 1))
3096         align = 4;
3097       index = fieldFromInstruction32(Insn, 5, 3);
3098       break;
3099     case 1:
3100       if (fieldFromInstruction32(Insn, 4, 1))
3101         align = 8;
3102       index = fieldFromInstruction32(Insn, 6, 2);
3103       if (fieldFromInstruction32(Insn, 5, 1))
3104         inc = 2;
3105       break;
3106     case 2:
3107       if (fieldFromInstruction32(Insn, 4, 2))
3108         align = 4 << fieldFromInstruction32(Insn, 4, 2);
3109       index = fieldFromInstruction32(Insn, 7, 1);
3110       if (fieldFromInstruction32(Insn, 6, 1))
3111         inc = 2;
3112       break;
3113   }
3114 
3115   if (Rm != 0xF) { // Writeback
3116     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
3117   }
3118   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
3119   Inst.addOperand(MCOperand::CreateImm(align));
3120   if (Rm != 0xF && Rm != 0xD) {
3121     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
3122   }
3123 
3124   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
3125   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
3126   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder));
3127   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder));
3128   Inst.addOperand(MCOperand::CreateImm(index));
3129 
3130   return S;
3131 }
3132 
3133