xref: /llvm-project/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp (revision d14b70d00bde54c94e025c516783cec4ee51d36d)
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   // imod == '01' --> UNPREDICTABLE
1321   if (imod == 1) return Fail;
1322 
1323   if (M && mode && imod && iflags) {
1324     Inst.setOpcode(ARM::CPS3p);
1325     Inst.addOperand(MCOperand::CreateImm(imod));
1326     Inst.addOperand(MCOperand::CreateImm(iflags));
1327     Inst.addOperand(MCOperand::CreateImm(mode));
1328     return Success;
1329   } else if (!mode && !M) {
1330     Inst.setOpcode(ARM::CPS2p);
1331     Inst.addOperand(MCOperand::CreateImm(imod));
1332     Inst.addOperand(MCOperand::CreateImm(iflags));
1333     return Success;
1334   } else if (!imod && !iflags && M) {
1335     Inst.setOpcode(ARM::CPS1p);
1336     Inst.addOperand(MCOperand::CreateImm(mode));
1337     return Success;
1338   }
1339 
1340   return Fail;
1341 }
1342 
1343 static DecodeStatus DecodeSMLAInstruction(llvm::MCInst &Inst, unsigned Insn,
1344                                  uint64_t Address, const void *Decoder) {
1345   DecodeStatus S = Success;
1346 
1347   unsigned Rd = fieldFromInstruction32(Insn, 16, 4);
1348   unsigned Rn = fieldFromInstruction32(Insn, 0, 4);
1349   unsigned Rm = fieldFromInstruction32(Insn, 8, 4);
1350   unsigned Ra = fieldFromInstruction32(Insn, 12, 4);
1351   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1352 
1353   if (pred == 0xF)
1354     return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
1355 
1356   CHECK(S, DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder));
1357   CHECK(S, DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder));
1358   CHECK(S, DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder));
1359   CHECK(S, DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder));
1360 
1361   CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
1362 
1363   return S;
1364 }
1365 
1366 static DecodeStatus DecodeAddrModeImm12Operand(llvm::MCInst &Inst, unsigned Val,
1367                            uint64_t Address, const void *Decoder) {
1368   DecodeStatus S = Success;
1369 
1370   unsigned add = fieldFromInstruction32(Val, 12, 1);
1371   unsigned imm = fieldFromInstruction32(Val, 0, 12);
1372   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
1373 
1374   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1375 
1376   if (!add) imm *= -1;
1377   if (imm == 0 && !add) imm = INT32_MIN;
1378   Inst.addOperand(MCOperand::CreateImm(imm));
1379 
1380   return S;
1381 }
1382 
1383 static DecodeStatus DecodeAddrMode5Operand(llvm::MCInst &Inst, unsigned Val,
1384                                    uint64_t Address, const void *Decoder) {
1385   DecodeStatus S = Success;
1386 
1387   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
1388   unsigned U = fieldFromInstruction32(Val, 8, 1);
1389   unsigned imm = fieldFromInstruction32(Val, 0, 8);
1390 
1391   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1392 
1393   if (U)
1394     Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
1395   else
1396     Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
1397 
1398   return S;
1399 }
1400 
1401 static DecodeStatus DecodeAddrMode7Operand(llvm::MCInst &Inst, unsigned Val,
1402                                    uint64_t Address, const void *Decoder) {
1403   return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
1404 }
1405 
1406 static DecodeStatus
1407 DecodeBranchImmInstruction(llvm::MCInst &Inst, unsigned Insn,
1408                            uint64_t Address, const void *Decoder) {
1409   DecodeStatus S = Success;
1410 
1411   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1412   unsigned imm = fieldFromInstruction32(Insn, 0, 24) << 2;
1413 
1414   if (pred == 0xF) {
1415     Inst.setOpcode(ARM::BLXi);
1416     imm |= fieldFromInstruction32(Insn, 24, 1) << 1;
1417     Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1418     return S;
1419   }
1420 
1421   Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1422   CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
1423 
1424   return S;
1425 }
1426 
1427 
1428 static DecodeStatus DecodeVCVTImmOperand(llvm::MCInst &Inst, unsigned Val,
1429                                  uint64_t Address, const void *Decoder) {
1430   Inst.addOperand(MCOperand::CreateImm(64 - Val));
1431   return Success;
1432 }
1433 
1434 static DecodeStatus DecodeAddrMode6Operand(llvm::MCInst &Inst, unsigned Val,
1435                                    uint64_t Address, const void *Decoder) {
1436   DecodeStatus S = Success;
1437 
1438   unsigned Rm = fieldFromInstruction32(Val, 0, 4);
1439   unsigned align = fieldFromInstruction32(Val, 4, 2);
1440 
1441   CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
1442   if (!align)
1443     Inst.addOperand(MCOperand::CreateImm(0));
1444   else
1445     Inst.addOperand(MCOperand::CreateImm(4 << align));
1446 
1447   return S;
1448 }
1449 
1450 static DecodeStatus DecodeVLDInstruction(llvm::MCInst &Inst, unsigned Insn,
1451                                    uint64_t Address, const void *Decoder) {
1452   DecodeStatus S = Success;
1453 
1454   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1455   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1456   unsigned wb = fieldFromInstruction32(Insn, 16, 4);
1457   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1458   Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
1459   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1460 
1461   // First output register
1462   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
1463 
1464   // Second output register
1465   switch (Inst.getOpcode()) {
1466     case ARM::VLD1q8:
1467     case ARM::VLD1q16:
1468     case ARM::VLD1q32:
1469     case ARM::VLD1q64:
1470     case ARM::VLD1q8_UPD:
1471     case ARM::VLD1q16_UPD:
1472     case ARM::VLD1q32_UPD:
1473     case ARM::VLD1q64_UPD:
1474     case ARM::VLD1d8T:
1475     case ARM::VLD1d16T:
1476     case ARM::VLD1d32T:
1477     case ARM::VLD1d64T:
1478     case ARM::VLD1d8T_UPD:
1479     case ARM::VLD1d16T_UPD:
1480     case ARM::VLD1d32T_UPD:
1481     case ARM::VLD1d64T_UPD:
1482     case ARM::VLD1d8Q:
1483     case ARM::VLD1d16Q:
1484     case ARM::VLD1d32Q:
1485     case ARM::VLD1d64Q:
1486     case ARM::VLD1d8Q_UPD:
1487     case ARM::VLD1d16Q_UPD:
1488     case ARM::VLD1d32Q_UPD:
1489     case ARM::VLD1d64Q_UPD:
1490     case ARM::VLD2d8:
1491     case ARM::VLD2d16:
1492     case ARM::VLD2d32:
1493     case ARM::VLD2d8_UPD:
1494     case ARM::VLD2d16_UPD:
1495     case ARM::VLD2d32_UPD:
1496     case ARM::VLD2q8:
1497     case ARM::VLD2q16:
1498     case ARM::VLD2q32:
1499     case ARM::VLD2q8_UPD:
1500     case ARM::VLD2q16_UPD:
1501     case ARM::VLD2q32_UPD:
1502     case ARM::VLD3d8:
1503     case ARM::VLD3d16:
1504     case ARM::VLD3d32:
1505     case ARM::VLD3d8_UPD:
1506     case ARM::VLD3d16_UPD:
1507     case ARM::VLD3d32_UPD:
1508     case ARM::VLD4d8:
1509     case ARM::VLD4d16:
1510     case ARM::VLD4d32:
1511     case ARM::VLD4d8_UPD:
1512     case ARM::VLD4d16_UPD:
1513     case ARM::VLD4d32_UPD:
1514       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder));
1515       break;
1516     case ARM::VLD2b8:
1517     case ARM::VLD2b16:
1518     case ARM::VLD2b32:
1519     case ARM::VLD2b8_UPD:
1520     case ARM::VLD2b16_UPD:
1521     case ARM::VLD2b32_UPD:
1522     case ARM::VLD3q8:
1523     case ARM::VLD3q16:
1524     case ARM::VLD3q32:
1525     case ARM::VLD3q8_UPD:
1526     case ARM::VLD3q16_UPD:
1527     case ARM::VLD3q32_UPD:
1528     case ARM::VLD4q8:
1529     case ARM::VLD4q16:
1530     case ARM::VLD4q32:
1531     case ARM::VLD4q8_UPD:
1532     case ARM::VLD4q16_UPD:
1533     case ARM::VLD4q32_UPD:
1534       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder));
1535     default:
1536       break;
1537   }
1538 
1539   // Third output register
1540   switch(Inst.getOpcode()) {
1541     case ARM::VLD1d8T:
1542     case ARM::VLD1d16T:
1543     case ARM::VLD1d32T:
1544     case ARM::VLD1d64T:
1545     case ARM::VLD1d8T_UPD:
1546     case ARM::VLD1d16T_UPD:
1547     case ARM::VLD1d32T_UPD:
1548     case ARM::VLD1d64T_UPD:
1549     case ARM::VLD1d8Q:
1550     case ARM::VLD1d16Q:
1551     case ARM::VLD1d32Q:
1552     case ARM::VLD1d64Q:
1553     case ARM::VLD1d8Q_UPD:
1554     case ARM::VLD1d16Q_UPD:
1555     case ARM::VLD1d32Q_UPD:
1556     case ARM::VLD1d64Q_UPD:
1557     case ARM::VLD2q8:
1558     case ARM::VLD2q16:
1559     case ARM::VLD2q32:
1560     case ARM::VLD2q8_UPD:
1561     case ARM::VLD2q16_UPD:
1562     case ARM::VLD2q32_UPD:
1563     case ARM::VLD3d8:
1564     case ARM::VLD3d16:
1565     case ARM::VLD3d32:
1566     case ARM::VLD3d8_UPD:
1567     case ARM::VLD3d16_UPD:
1568     case ARM::VLD3d32_UPD:
1569     case ARM::VLD4d8:
1570     case ARM::VLD4d16:
1571     case ARM::VLD4d32:
1572     case ARM::VLD4d8_UPD:
1573     case ARM::VLD4d16_UPD:
1574     case ARM::VLD4d32_UPD:
1575       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder));
1576       break;
1577     case ARM::VLD3q8:
1578     case ARM::VLD3q16:
1579     case ARM::VLD3q32:
1580     case ARM::VLD3q8_UPD:
1581     case ARM::VLD3q16_UPD:
1582     case ARM::VLD3q32_UPD:
1583     case ARM::VLD4q8:
1584     case ARM::VLD4q16:
1585     case ARM::VLD4q32:
1586     case ARM::VLD4q8_UPD:
1587     case ARM::VLD4q16_UPD:
1588     case ARM::VLD4q32_UPD:
1589       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder));
1590       break;
1591     default:
1592       break;
1593   }
1594 
1595   // Fourth output register
1596   switch (Inst.getOpcode()) {
1597     case ARM::VLD1d8Q:
1598     case ARM::VLD1d16Q:
1599     case ARM::VLD1d32Q:
1600     case ARM::VLD1d64Q:
1601     case ARM::VLD1d8Q_UPD:
1602     case ARM::VLD1d16Q_UPD:
1603     case ARM::VLD1d32Q_UPD:
1604     case ARM::VLD1d64Q_UPD:
1605     case ARM::VLD2q8:
1606     case ARM::VLD2q16:
1607     case ARM::VLD2q32:
1608     case ARM::VLD2q8_UPD:
1609     case ARM::VLD2q16_UPD:
1610     case ARM::VLD2q32_UPD:
1611     case ARM::VLD4d8:
1612     case ARM::VLD4d16:
1613     case ARM::VLD4d32:
1614     case ARM::VLD4d8_UPD:
1615     case ARM::VLD4d16_UPD:
1616     case ARM::VLD4d32_UPD:
1617       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder));
1618       break;
1619     case ARM::VLD4q8:
1620     case ARM::VLD4q16:
1621     case ARM::VLD4q32:
1622     case ARM::VLD4q8_UPD:
1623     case ARM::VLD4q16_UPD:
1624     case ARM::VLD4q32_UPD:
1625       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder));
1626       break;
1627     default:
1628       break;
1629   }
1630 
1631   // Writeback operand
1632   switch (Inst.getOpcode()) {
1633     case ARM::VLD1d8_UPD:
1634     case ARM::VLD1d16_UPD:
1635     case ARM::VLD1d32_UPD:
1636     case ARM::VLD1d64_UPD:
1637     case ARM::VLD1q8_UPD:
1638     case ARM::VLD1q16_UPD:
1639     case ARM::VLD1q32_UPD:
1640     case ARM::VLD1q64_UPD:
1641     case ARM::VLD1d8T_UPD:
1642     case ARM::VLD1d16T_UPD:
1643     case ARM::VLD1d32T_UPD:
1644     case ARM::VLD1d64T_UPD:
1645     case ARM::VLD1d8Q_UPD:
1646     case ARM::VLD1d16Q_UPD:
1647     case ARM::VLD1d32Q_UPD:
1648     case ARM::VLD1d64Q_UPD:
1649     case ARM::VLD2d8_UPD:
1650     case ARM::VLD2d16_UPD:
1651     case ARM::VLD2d32_UPD:
1652     case ARM::VLD2q8_UPD:
1653     case ARM::VLD2q16_UPD:
1654     case ARM::VLD2q32_UPD:
1655     case ARM::VLD2b8_UPD:
1656     case ARM::VLD2b16_UPD:
1657     case ARM::VLD2b32_UPD:
1658     case ARM::VLD3d8_UPD:
1659     case ARM::VLD3d16_UPD:
1660     case ARM::VLD3d32_UPD:
1661     case ARM::VLD3q8_UPD:
1662     case ARM::VLD3q16_UPD:
1663     case ARM::VLD3q32_UPD:
1664     case ARM::VLD4d8_UPD:
1665     case ARM::VLD4d16_UPD:
1666     case ARM::VLD4d32_UPD:
1667     case ARM::VLD4q8_UPD:
1668     case ARM::VLD4q16_UPD:
1669     case ARM::VLD4q32_UPD:
1670       CHECK(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder));
1671       break;
1672     default:
1673       break;
1674   }
1675 
1676   // AddrMode6 Base (register+alignment)
1677   CHECK(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder));
1678 
1679   // AddrMode6 Offset (register)
1680   if (Rm == 0xD)
1681     Inst.addOperand(MCOperand::CreateReg(0));
1682   else if (Rm != 0xF) {
1683     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
1684   }
1685 
1686   return S;
1687 }
1688 
1689 static DecodeStatus DecodeVSTInstruction(llvm::MCInst &Inst, unsigned Insn,
1690                                  uint64_t Address, const void *Decoder) {
1691   DecodeStatus S = Success;
1692 
1693   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1694   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1695   unsigned wb = fieldFromInstruction32(Insn, 16, 4);
1696   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1697   Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
1698   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1699 
1700   // Writeback Operand
1701   switch (Inst.getOpcode()) {
1702     case ARM::VST1d8_UPD:
1703     case ARM::VST1d16_UPD:
1704     case ARM::VST1d32_UPD:
1705     case ARM::VST1d64_UPD:
1706     case ARM::VST1q8_UPD:
1707     case ARM::VST1q16_UPD:
1708     case ARM::VST1q32_UPD:
1709     case ARM::VST1q64_UPD:
1710     case ARM::VST1d8T_UPD:
1711     case ARM::VST1d16T_UPD:
1712     case ARM::VST1d32T_UPD:
1713     case ARM::VST1d64T_UPD:
1714     case ARM::VST1d8Q_UPD:
1715     case ARM::VST1d16Q_UPD:
1716     case ARM::VST1d32Q_UPD:
1717     case ARM::VST1d64Q_UPD:
1718     case ARM::VST2d8_UPD:
1719     case ARM::VST2d16_UPD:
1720     case ARM::VST2d32_UPD:
1721     case ARM::VST2q8_UPD:
1722     case ARM::VST2q16_UPD:
1723     case ARM::VST2q32_UPD:
1724     case ARM::VST2b8_UPD:
1725     case ARM::VST2b16_UPD:
1726     case ARM::VST2b32_UPD:
1727     case ARM::VST3d8_UPD:
1728     case ARM::VST3d16_UPD:
1729     case ARM::VST3d32_UPD:
1730     case ARM::VST3q8_UPD:
1731     case ARM::VST3q16_UPD:
1732     case ARM::VST3q32_UPD:
1733     case ARM::VST4d8_UPD:
1734     case ARM::VST4d16_UPD:
1735     case ARM::VST4d32_UPD:
1736     case ARM::VST4q8_UPD:
1737     case ARM::VST4q16_UPD:
1738     case ARM::VST4q32_UPD:
1739       CHECK(S, DecodeGPRRegisterClass(Inst, wb, Address, Decoder));
1740       break;
1741     default:
1742       break;
1743   }
1744 
1745   // AddrMode6 Base (register+alignment)
1746   CHECK(S, DecodeAddrMode6Operand(Inst, Rn, Address, Decoder));
1747 
1748   // AddrMode6 Offset (register)
1749   if (Rm == 0xD)
1750     Inst.addOperand(MCOperand::CreateReg(0));
1751   else if (Rm != 0xF) {
1752     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
1753   }
1754 
1755   // First input register
1756   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
1757 
1758   // Second input register
1759   switch (Inst.getOpcode()) {
1760     case ARM::VST1q8:
1761     case ARM::VST1q16:
1762     case ARM::VST1q32:
1763     case ARM::VST1q64:
1764     case ARM::VST1q8_UPD:
1765     case ARM::VST1q16_UPD:
1766     case ARM::VST1q32_UPD:
1767     case ARM::VST1q64_UPD:
1768     case ARM::VST1d8T:
1769     case ARM::VST1d16T:
1770     case ARM::VST1d32T:
1771     case ARM::VST1d64T:
1772     case ARM::VST1d8T_UPD:
1773     case ARM::VST1d16T_UPD:
1774     case ARM::VST1d32T_UPD:
1775     case ARM::VST1d64T_UPD:
1776     case ARM::VST1d8Q:
1777     case ARM::VST1d16Q:
1778     case ARM::VST1d32Q:
1779     case ARM::VST1d64Q:
1780     case ARM::VST1d8Q_UPD:
1781     case ARM::VST1d16Q_UPD:
1782     case ARM::VST1d32Q_UPD:
1783     case ARM::VST1d64Q_UPD:
1784     case ARM::VST2d8:
1785     case ARM::VST2d16:
1786     case ARM::VST2d32:
1787     case ARM::VST2d8_UPD:
1788     case ARM::VST2d16_UPD:
1789     case ARM::VST2d32_UPD:
1790     case ARM::VST2q8:
1791     case ARM::VST2q16:
1792     case ARM::VST2q32:
1793     case ARM::VST2q8_UPD:
1794     case ARM::VST2q16_UPD:
1795     case ARM::VST2q32_UPD:
1796     case ARM::VST3d8:
1797     case ARM::VST3d16:
1798     case ARM::VST3d32:
1799     case ARM::VST3d8_UPD:
1800     case ARM::VST3d16_UPD:
1801     case ARM::VST3d32_UPD:
1802     case ARM::VST4d8:
1803     case ARM::VST4d16:
1804     case ARM::VST4d32:
1805     case ARM::VST4d8_UPD:
1806     case ARM::VST4d16_UPD:
1807     case ARM::VST4d32_UPD:
1808       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder));
1809       break;
1810     case ARM::VST2b8:
1811     case ARM::VST2b16:
1812     case ARM::VST2b32:
1813     case ARM::VST2b8_UPD:
1814     case ARM::VST2b16_UPD:
1815     case ARM::VST2b32_UPD:
1816     case ARM::VST3q8:
1817     case ARM::VST3q16:
1818     case ARM::VST3q32:
1819     case ARM::VST3q8_UPD:
1820     case ARM::VST3q16_UPD:
1821     case ARM::VST3q32_UPD:
1822     case ARM::VST4q8:
1823     case ARM::VST4q16:
1824     case ARM::VST4q32:
1825     case ARM::VST4q8_UPD:
1826     case ARM::VST4q16_UPD:
1827     case ARM::VST4q32_UPD:
1828       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder));
1829       break;
1830     default:
1831       break;
1832   }
1833 
1834   // Third input register
1835   switch (Inst.getOpcode()) {
1836     case ARM::VST1d8T:
1837     case ARM::VST1d16T:
1838     case ARM::VST1d32T:
1839     case ARM::VST1d64T:
1840     case ARM::VST1d8T_UPD:
1841     case ARM::VST1d16T_UPD:
1842     case ARM::VST1d32T_UPD:
1843     case ARM::VST1d64T_UPD:
1844     case ARM::VST1d8Q:
1845     case ARM::VST1d16Q:
1846     case ARM::VST1d32Q:
1847     case ARM::VST1d64Q:
1848     case ARM::VST1d8Q_UPD:
1849     case ARM::VST1d16Q_UPD:
1850     case ARM::VST1d32Q_UPD:
1851     case ARM::VST1d64Q_UPD:
1852     case ARM::VST2q8:
1853     case ARM::VST2q16:
1854     case ARM::VST2q32:
1855     case ARM::VST2q8_UPD:
1856     case ARM::VST2q16_UPD:
1857     case ARM::VST2q32_UPD:
1858     case ARM::VST3d8:
1859     case ARM::VST3d16:
1860     case ARM::VST3d32:
1861     case ARM::VST3d8_UPD:
1862     case ARM::VST3d16_UPD:
1863     case ARM::VST3d32_UPD:
1864     case ARM::VST4d8:
1865     case ARM::VST4d16:
1866     case ARM::VST4d32:
1867     case ARM::VST4d8_UPD:
1868     case ARM::VST4d16_UPD:
1869     case ARM::VST4d32_UPD:
1870       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder));
1871       break;
1872     case ARM::VST3q8:
1873     case ARM::VST3q16:
1874     case ARM::VST3q32:
1875     case ARM::VST3q8_UPD:
1876     case ARM::VST3q16_UPD:
1877     case ARM::VST3q32_UPD:
1878     case ARM::VST4q8:
1879     case ARM::VST4q16:
1880     case ARM::VST4q32:
1881     case ARM::VST4q8_UPD:
1882     case ARM::VST4q16_UPD:
1883     case ARM::VST4q32_UPD:
1884       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder));
1885       break;
1886     default:
1887       break;
1888   }
1889 
1890   // Fourth input register
1891   switch (Inst.getOpcode()) {
1892     case ARM::VST1d8Q:
1893     case ARM::VST1d16Q:
1894     case ARM::VST1d32Q:
1895     case ARM::VST1d64Q:
1896     case ARM::VST1d8Q_UPD:
1897     case ARM::VST1d16Q_UPD:
1898     case ARM::VST1d32Q_UPD:
1899     case ARM::VST1d64Q_UPD:
1900     case ARM::VST2q8:
1901     case ARM::VST2q16:
1902     case ARM::VST2q32:
1903     case ARM::VST2q8_UPD:
1904     case ARM::VST2q16_UPD:
1905     case ARM::VST2q32_UPD:
1906     case ARM::VST4d8:
1907     case ARM::VST4d16:
1908     case ARM::VST4d32:
1909     case ARM::VST4d8_UPD:
1910     case ARM::VST4d16_UPD:
1911     case ARM::VST4d32_UPD:
1912       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder));
1913       break;
1914     case ARM::VST4q8:
1915     case ARM::VST4q16:
1916     case ARM::VST4q32:
1917     case ARM::VST4q8_UPD:
1918     case ARM::VST4q16_UPD:
1919     case ARM::VST4q32_UPD:
1920       CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder));
1921       break;
1922     default:
1923       break;
1924   }
1925 
1926   return S;
1927 }
1928 
1929 static DecodeStatus DecodeVLD1DupInstruction(llvm::MCInst &Inst, unsigned Insn,
1930                                     uint64_t Address, const void *Decoder) {
1931   DecodeStatus S = Success;
1932 
1933   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1934   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1935   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1936   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1937   unsigned align = fieldFromInstruction32(Insn, 4, 1);
1938   unsigned size = fieldFromInstruction32(Insn, 6, 2);
1939   unsigned regs = fieldFromInstruction32(Insn, 5, 1) + 1;
1940 
1941   align *= (1 << size);
1942 
1943   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
1944   if (regs == 2) {
1945     CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder));
1946   }
1947   if (Rm == 0xD) {
1948     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1949   }
1950 
1951   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1952   Inst.addOperand(MCOperand::CreateImm(align));
1953 
1954   if (Rm == 0xD)
1955     Inst.addOperand(MCOperand::CreateReg(0));
1956   else if (Rm != 0xF) {
1957     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
1958   }
1959 
1960   return S;
1961 }
1962 
1963 static DecodeStatus DecodeVLD2DupInstruction(llvm::MCInst &Inst, unsigned Insn,
1964                                     uint64_t Address, const void *Decoder) {
1965   DecodeStatus S = Success;
1966 
1967   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1968   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1969   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1970   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1971   unsigned align = fieldFromInstruction32(Insn, 4, 1);
1972   unsigned size = 1 << fieldFromInstruction32(Insn, 6, 2);
1973   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
1974   align *= 2*size;
1975 
1976   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
1977   CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder));
1978   if (Rm == 0xD) {
1979     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1980   }
1981 
1982   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
1983   Inst.addOperand(MCOperand::CreateImm(align));
1984 
1985   if (Rm == 0xD)
1986     Inst.addOperand(MCOperand::CreateReg(0));
1987   else if (Rm != 0xF) {
1988     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
1989   }
1990 
1991   return S;
1992 }
1993 
1994 static DecodeStatus DecodeVLD3DupInstruction(llvm::MCInst &Inst, unsigned Insn,
1995                                     uint64_t Address, const void *Decoder) {
1996   DecodeStatus S = Success;
1997 
1998   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1999   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2000   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2001   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2002   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2003 
2004   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2005   CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder));
2006   CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder));
2007   if (Rm == 0xD) {
2008     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2009   }
2010 
2011   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2012   Inst.addOperand(MCOperand::CreateImm(0));
2013 
2014   if (Rm == 0xD)
2015     Inst.addOperand(MCOperand::CreateReg(0));
2016   else if (Rm != 0xF) {
2017     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
2018   }
2019 
2020   return S;
2021 }
2022 
2023 static DecodeStatus DecodeVLD4DupInstruction(llvm::MCInst &Inst, unsigned Insn,
2024                                     uint64_t Address, const void *Decoder) {
2025   DecodeStatus S = Success;
2026 
2027   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2028   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2029   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2030   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2031   unsigned size = fieldFromInstruction32(Insn, 6, 2);
2032   unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
2033   unsigned align = fieldFromInstruction32(Insn, 4, 1);
2034 
2035   if (size == 0x3) {
2036     size = 4;
2037     align = 16;
2038   } else {
2039     if (size == 2) {
2040       size = 1 << size;
2041       align *= 8;
2042     } else {
2043       size = 1 << size;
2044       align *= 4*size;
2045     }
2046   }
2047 
2048   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2049   CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder));
2050   CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder));
2051   CHECK(S, DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder));
2052   if (Rm == 0xD) {
2053     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2054   }
2055 
2056   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2057   Inst.addOperand(MCOperand::CreateImm(align));
2058 
2059   if (Rm == 0xD)
2060     Inst.addOperand(MCOperand::CreateReg(0));
2061   else if (Rm != 0xF) {
2062     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
2063   }
2064 
2065   return S;
2066 }
2067 
2068 static DecodeStatus
2069 DecodeNEONModImmInstruction(llvm::MCInst &Inst, unsigned Insn,
2070                             uint64_t Address, const void *Decoder) {
2071   DecodeStatus S = Success;
2072 
2073   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2074   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2075   unsigned imm = fieldFromInstruction32(Insn, 0, 4);
2076   imm |= fieldFromInstruction32(Insn, 16, 3) << 4;
2077   imm |= fieldFromInstruction32(Insn, 24, 1) << 7;
2078   imm |= fieldFromInstruction32(Insn, 8, 4) << 8;
2079   imm |= fieldFromInstruction32(Insn, 5, 1) << 12;
2080   unsigned Q = fieldFromInstruction32(Insn, 6, 1);
2081 
2082   if (Q) {
2083     CHECK(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder));
2084   } else {
2085     CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2086   }
2087 
2088   Inst.addOperand(MCOperand::CreateImm(imm));
2089 
2090   switch (Inst.getOpcode()) {
2091     case ARM::VORRiv4i16:
2092     case ARM::VORRiv2i32:
2093     case ARM::VBICiv4i16:
2094     case ARM::VBICiv2i32:
2095       CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2096       break;
2097     case ARM::VORRiv8i16:
2098     case ARM::VORRiv4i32:
2099     case ARM::VBICiv8i16:
2100     case ARM::VBICiv4i32:
2101       CHECK(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder));
2102       break;
2103     default:
2104       break;
2105   }
2106 
2107   return S;
2108 }
2109 
2110 static DecodeStatus DecodeVSHLMaxInstruction(llvm::MCInst &Inst, unsigned Insn,
2111                                         uint64_t Address, const void *Decoder) {
2112   DecodeStatus S = Success;
2113 
2114   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2115   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2116   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2117   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2118   unsigned size = fieldFromInstruction32(Insn, 18, 2);
2119 
2120   CHECK(S, DecodeQPRRegisterClass(Inst, Rd, Address, Decoder));
2121   CHECK(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder));
2122   Inst.addOperand(MCOperand::CreateImm(8 << size));
2123 
2124   return S;
2125 }
2126 
2127 static DecodeStatus DecodeShiftRight8Imm(llvm::MCInst &Inst, unsigned Val,
2128                                uint64_t Address, const void *Decoder) {
2129   Inst.addOperand(MCOperand::CreateImm(8 - Val));
2130   return Success;
2131 }
2132 
2133 static DecodeStatus DecodeShiftRight16Imm(llvm::MCInst &Inst, unsigned Val,
2134                                uint64_t Address, const void *Decoder) {
2135   Inst.addOperand(MCOperand::CreateImm(16 - Val));
2136   return Success;
2137 }
2138 
2139 static DecodeStatus DecodeShiftRight32Imm(llvm::MCInst &Inst, unsigned Val,
2140                                uint64_t Address, const void *Decoder) {
2141   Inst.addOperand(MCOperand::CreateImm(32 - Val));
2142   return Success;
2143 }
2144 
2145 static DecodeStatus DecodeShiftRight64Imm(llvm::MCInst &Inst, unsigned Val,
2146                                uint64_t Address, const void *Decoder) {
2147   Inst.addOperand(MCOperand::CreateImm(64 - Val));
2148   return Success;
2149 }
2150 
2151 static DecodeStatus DecodeTBLInstruction(llvm::MCInst &Inst, unsigned Insn,
2152                                uint64_t Address, const void *Decoder) {
2153   DecodeStatus S = Success;
2154 
2155   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2156   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2157   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2158   Rn |= fieldFromInstruction32(Insn, 7, 1) << 4;
2159   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2160   Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2161   unsigned op = fieldFromInstruction32(Insn, 6, 1);
2162   unsigned length = fieldFromInstruction32(Insn, 8, 2) + 1;
2163 
2164   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2165   if (op) {
2166     CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)); // Writeback
2167   }
2168 
2169   for (unsigned i = 0; i < length; ++i) {
2170     CHECK(S, DecodeDPRRegisterClass(Inst, (Rn+i)%32, Address, Decoder));
2171   }
2172 
2173   CHECK(S, DecodeDPRRegisterClass(Inst, Rm, Address, Decoder));
2174 
2175   return S;
2176 }
2177 
2178 static DecodeStatus DecodeVFPfpImm(llvm::MCInst &Inst, unsigned Val,
2179                             uint64_t Address, const void *Decoder) {
2180   // The immediate needs to be a fully instantiated float.  However, the
2181   // auto-generated decoder is only able to fill in some of the bits
2182   // necessary.  For instance, the 'b' bit is replicated multiple times,
2183   // and is even present in inverted form in one bit.  We do a little
2184   // binary parsing here to fill in those missing bits, and then
2185   // reinterpret it all as a float.
2186   union {
2187     uint32_t integer;
2188     float fp;
2189   } fp_conv;
2190 
2191   fp_conv.integer = Val;
2192   uint32_t b = fieldFromInstruction32(Val, 25, 1);
2193   fp_conv.integer |= b << 26;
2194   fp_conv.integer |= b << 27;
2195   fp_conv.integer |= b << 28;
2196   fp_conv.integer |= b << 29;
2197   fp_conv.integer |= (~b & 0x1) << 30;
2198 
2199   Inst.addOperand(MCOperand::CreateFPImm(fp_conv.fp));
2200   return Success;
2201 }
2202 
2203 static DecodeStatus DecodeThumbAddSpecialReg(llvm::MCInst &Inst, uint16_t Insn,
2204                                      uint64_t Address, const void *Decoder) {
2205   DecodeStatus S = Success;
2206 
2207   unsigned dst = fieldFromInstruction16(Insn, 8, 3);
2208   unsigned imm = fieldFromInstruction16(Insn, 0, 8);
2209 
2210   CHECK(S, DecodetGPRRegisterClass(Inst, dst, Address, Decoder));
2211 
2212   if (Inst.getOpcode() == ARM::tADR)
2213     Inst.addOperand(MCOperand::CreateReg(ARM::PC));
2214   else if (Inst.getOpcode() == ARM::tADDrSPi)
2215     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2216   else
2217     return Fail;
2218 
2219   Inst.addOperand(MCOperand::CreateImm(imm));
2220   return S;
2221 }
2222 
2223 static DecodeStatus DecodeThumbBROperand(llvm::MCInst &Inst, unsigned Val,
2224                                  uint64_t Address, const void *Decoder) {
2225   Inst.addOperand(MCOperand::CreateImm(SignExtend32<12>(Val << 1)));
2226   return Success;
2227 }
2228 
2229 static DecodeStatus DecodeT2BROperand(llvm::MCInst &Inst, unsigned Val,
2230                                  uint64_t Address, const void *Decoder) {
2231   Inst.addOperand(MCOperand::CreateImm(SignExtend32<21>(Val)));
2232   return Success;
2233 }
2234 
2235 static DecodeStatus DecodeThumbCmpBROperand(llvm::MCInst &Inst, unsigned Val,
2236                                  uint64_t Address, const void *Decoder) {
2237   Inst.addOperand(MCOperand::CreateImm(SignExtend32<7>(Val << 1)));
2238   return Success;
2239 }
2240 
2241 static DecodeStatus DecodeThumbAddrModeRR(llvm::MCInst &Inst, unsigned Val,
2242                                  uint64_t Address, const void *Decoder) {
2243   DecodeStatus S = Success;
2244 
2245   unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2246   unsigned Rm = fieldFromInstruction32(Val, 3, 3);
2247 
2248   CHECK(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder));
2249   CHECK(S, DecodetGPRRegisterClass(Inst, Rm, Address, Decoder));
2250 
2251   return S;
2252 }
2253 
2254 static DecodeStatus DecodeThumbAddrModeIS(llvm::MCInst &Inst, unsigned Val,
2255                                   uint64_t Address, const void *Decoder) {
2256   DecodeStatus S = Success;
2257 
2258   unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2259   unsigned imm = fieldFromInstruction32(Val, 3, 5);
2260 
2261   CHECK(S, DecodetGPRRegisterClass(Inst, Rn, Address, Decoder));
2262   Inst.addOperand(MCOperand::CreateImm(imm));
2263 
2264   return S;
2265 }
2266 
2267 static DecodeStatus DecodeThumbAddrModePC(llvm::MCInst &Inst, unsigned Val,
2268                                   uint64_t Address, const void *Decoder) {
2269   Inst.addOperand(MCOperand::CreateImm(Val << 2));
2270 
2271   return Success;
2272 }
2273 
2274 static DecodeStatus DecodeThumbAddrModeSP(llvm::MCInst &Inst, unsigned Val,
2275                                   uint64_t Address, const void *Decoder) {
2276   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2277   Inst.addOperand(MCOperand::CreateImm(Val << 2));
2278 
2279   return Success;
2280 }
2281 
2282 static DecodeStatus DecodeT2AddrModeSOReg(llvm::MCInst &Inst, unsigned Val,
2283                                   uint64_t Address, const void *Decoder) {
2284   DecodeStatus S = Success;
2285 
2286   unsigned Rn = fieldFromInstruction32(Val, 6, 4);
2287   unsigned Rm = fieldFromInstruction32(Val, 2, 4);
2288   unsigned imm = fieldFromInstruction32(Val, 0, 2);
2289 
2290   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2291   CHECK(S, DecoderGPRRegisterClass(Inst, Rm, Address, Decoder));
2292   Inst.addOperand(MCOperand::CreateImm(imm));
2293 
2294   return S;
2295 }
2296 
2297 static DecodeStatus DecodeT2LoadShift(llvm::MCInst &Inst, unsigned Insn,
2298                               uint64_t Address, const void *Decoder) {
2299   DecodeStatus S = Success;
2300 
2301   if (Inst.getOpcode() != ARM::t2PLDs) {
2302     unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2303     CHECK(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
2304   }
2305 
2306   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2307   if (Rn == 0xF) {
2308     switch (Inst.getOpcode()) {
2309       case ARM::t2LDRBs:
2310         Inst.setOpcode(ARM::t2LDRBpci);
2311         break;
2312       case ARM::t2LDRHs:
2313         Inst.setOpcode(ARM::t2LDRHpci);
2314         break;
2315       case ARM::t2LDRSHs:
2316         Inst.setOpcode(ARM::t2LDRSHpci);
2317         break;
2318       case ARM::t2LDRSBs:
2319         Inst.setOpcode(ARM::t2LDRSBpci);
2320         break;
2321       case ARM::t2PLDs:
2322         Inst.setOpcode(ARM::t2PLDi12);
2323         Inst.addOperand(MCOperand::CreateReg(ARM::PC));
2324         break;
2325       default:
2326         return Fail;
2327     }
2328 
2329     int imm = fieldFromInstruction32(Insn, 0, 12);
2330     if (!fieldFromInstruction32(Insn, 23, 1)) imm *= -1;
2331     Inst.addOperand(MCOperand::CreateImm(imm));
2332 
2333     return S;
2334   }
2335 
2336   unsigned addrmode = fieldFromInstruction32(Insn, 4, 2);
2337   addrmode |= fieldFromInstruction32(Insn, 0, 4) << 2;
2338   addrmode |= fieldFromInstruction32(Insn, 16, 4) << 6;
2339   CHECK(S, DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder));
2340 
2341   return S;
2342 }
2343 
2344 static DecodeStatus DecodeT2Imm8S4(llvm::MCInst &Inst, unsigned Val,
2345                            uint64_t Address, const void *Decoder) {
2346   int imm = Val & 0xFF;
2347   if (!(Val & 0x100)) imm *= -1;
2348   Inst.addOperand(MCOperand::CreateImm(imm << 2));
2349 
2350   return Success;
2351 }
2352 
2353 static DecodeStatus DecodeT2AddrModeImm8s4(llvm::MCInst &Inst, unsigned Val,
2354                                    uint64_t Address, const void *Decoder) {
2355   DecodeStatus S = Success;
2356 
2357   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2358   unsigned imm = fieldFromInstruction32(Val, 0, 9);
2359 
2360   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2361   CHECK(S, DecodeT2Imm8S4(Inst, imm, Address, Decoder));
2362 
2363   return S;
2364 }
2365 
2366 static DecodeStatus DecodeT2Imm8(llvm::MCInst &Inst, unsigned Val,
2367                          uint64_t Address, const void *Decoder) {
2368   int imm = Val & 0xFF;
2369   if (!(Val & 0x100)) imm *= -1;
2370   Inst.addOperand(MCOperand::CreateImm(imm));
2371 
2372   return Success;
2373 }
2374 
2375 
2376 static DecodeStatus DecodeT2AddrModeImm8(llvm::MCInst &Inst, unsigned Val,
2377                                  uint64_t Address, const void *Decoder) {
2378   DecodeStatus S = Success;
2379 
2380   unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2381   unsigned imm = fieldFromInstruction32(Val, 0, 9);
2382 
2383   // Some instructions always use an additive offset.
2384   switch (Inst.getOpcode()) {
2385     case ARM::t2LDRT:
2386     case ARM::t2LDRBT:
2387     case ARM::t2LDRHT:
2388     case ARM::t2LDRSBT:
2389     case ARM::t2LDRSHT:
2390       imm |= 0x100;
2391       break;
2392     default:
2393       break;
2394   }
2395 
2396   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2397   CHECK(S, DecodeT2Imm8(Inst, imm, Address, Decoder));
2398 
2399   return S;
2400 }
2401 
2402 
2403 static DecodeStatus DecodeT2AddrModeImm12(llvm::MCInst &Inst, unsigned Val,
2404                                   uint64_t Address, const void *Decoder) {
2405   DecodeStatus S = Success;
2406 
2407   unsigned Rn = fieldFromInstruction32(Val, 13, 4);
2408   unsigned imm = fieldFromInstruction32(Val, 0, 12);
2409 
2410   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2411   Inst.addOperand(MCOperand::CreateImm(imm));
2412 
2413   return S;
2414 }
2415 
2416 
2417 static DecodeStatus DecodeThumbAddSPImm(llvm::MCInst &Inst, uint16_t Insn,
2418                                 uint64_t Address, const void *Decoder) {
2419   unsigned imm = fieldFromInstruction16(Insn, 0, 7);
2420 
2421   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2422   Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2423   Inst.addOperand(MCOperand::CreateImm(imm));
2424 
2425   return Success;
2426 }
2427 
2428 static DecodeStatus DecodeThumbAddSPReg(llvm::MCInst &Inst, uint16_t Insn,
2429                                 uint64_t Address, const void *Decoder) {
2430   DecodeStatus S = Success;
2431 
2432   if (Inst.getOpcode() == ARM::tADDrSP) {
2433     unsigned Rdm = fieldFromInstruction16(Insn, 0, 3);
2434     Rdm |= fieldFromInstruction16(Insn, 7, 1) << 3;
2435 
2436     CHECK(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder));
2437     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2438     CHECK(S, DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder));
2439   } else if (Inst.getOpcode() == ARM::tADDspr) {
2440     unsigned Rm = fieldFromInstruction16(Insn, 3, 4);
2441 
2442     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2443     Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2444     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
2445   }
2446 
2447   return S;
2448 }
2449 
2450 static DecodeStatus DecodeThumbCPS(llvm::MCInst &Inst, uint16_t Insn,
2451                            uint64_t Address, const void *Decoder) {
2452   unsigned imod = fieldFromInstruction16(Insn, 4, 1) | 0x2;
2453   unsigned flags = fieldFromInstruction16(Insn, 0, 3);
2454 
2455   Inst.addOperand(MCOperand::CreateImm(imod));
2456   Inst.addOperand(MCOperand::CreateImm(flags));
2457 
2458   return Success;
2459 }
2460 
2461 static DecodeStatus DecodePostIdxReg(llvm::MCInst &Inst, unsigned Insn,
2462                              uint64_t Address, const void *Decoder) {
2463   DecodeStatus S = Success;
2464   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2465   unsigned add = fieldFromInstruction32(Insn, 4, 1);
2466 
2467   CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) ;
2468   Inst.addOperand(MCOperand::CreateImm(add));
2469 
2470   return S;
2471 }
2472 
2473 static DecodeStatus DecodeThumbBLXOffset(llvm::MCInst &Inst, unsigned Val,
2474                                  uint64_t Address, const void *Decoder) {
2475   Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
2476   return Success;
2477 }
2478 
2479 static DecodeStatus DecodeCoprocessor(llvm::MCInst &Inst, unsigned Val,
2480                               uint64_t Address, const void *Decoder) {
2481   if (Val == 0xA || Val == 0xB)
2482     return Fail;
2483 
2484   Inst.addOperand(MCOperand::CreateImm(Val));
2485   return Success;
2486 }
2487 
2488 static DecodeStatus
2489 DecodeThumb2BCCInstruction(llvm::MCInst &Inst, unsigned Insn,
2490                            uint64_t Address, const void *Decoder) {
2491   DecodeStatus S = Success;
2492 
2493   unsigned pred = fieldFromInstruction32(Insn, 22, 4);
2494   if (pred == 0xE || pred == 0xF) {
2495     unsigned opc = fieldFromInstruction32(Insn, 4, 2);
2496     switch (opc) {
2497       default:
2498         return Fail;
2499       case 0:
2500         Inst.setOpcode(ARM::t2DSB);
2501         break;
2502       case 1:
2503         Inst.setOpcode(ARM::t2DMB);
2504         break;
2505       case 2:
2506         Inst.setOpcode(ARM::t2ISB);
2507         return Success;
2508     }
2509 
2510     unsigned imm = fieldFromInstruction32(Insn, 0, 4);
2511     return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
2512   }
2513 
2514   unsigned brtarget = fieldFromInstruction32(Insn, 0, 11) << 1;
2515   brtarget |= fieldFromInstruction32(Insn, 11, 1) << 19;
2516   brtarget |= fieldFromInstruction32(Insn, 13, 1) << 18;
2517   brtarget |= fieldFromInstruction32(Insn, 16, 6) << 12;
2518   brtarget |= fieldFromInstruction32(Insn, 26, 1) << 20;
2519 
2520   CHECK(S, DecodeT2BROperand(Inst, brtarget, Address, Decoder));
2521   CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
2522 
2523   return S;
2524 }
2525 
2526 // Decode a shifted immediate operand.  These basically consist
2527 // of an 8-bit value, and a 4-bit directive that specifies either
2528 // a splat operation or a rotation.
2529 static DecodeStatus DecodeT2SOImm(llvm::MCInst &Inst, unsigned Val,
2530                           uint64_t Address, const void *Decoder) {
2531   unsigned ctrl = fieldFromInstruction32(Val, 10, 2);
2532   if (ctrl == 0) {
2533     unsigned byte = fieldFromInstruction32(Val, 8, 2);
2534     unsigned imm = fieldFromInstruction32(Val, 0, 8);
2535     switch (byte) {
2536       case 0:
2537         Inst.addOperand(MCOperand::CreateImm(imm));
2538         break;
2539       case 1:
2540         Inst.addOperand(MCOperand::CreateImm((imm << 16) | imm));
2541         break;
2542       case 2:
2543         Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 8)));
2544         break;
2545       case 3:
2546         Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 16) |
2547                                              (imm << 8)  |  imm));
2548         break;
2549     }
2550   } else {
2551     unsigned unrot = fieldFromInstruction32(Val, 0, 7) | 0x80;
2552     unsigned rot = fieldFromInstruction32(Val, 7, 5);
2553     unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
2554     Inst.addOperand(MCOperand::CreateImm(imm));
2555   }
2556 
2557   return Success;
2558 }
2559 
2560 static DecodeStatus
2561 DecodeThumbBCCTargetOperand(llvm::MCInst &Inst, unsigned Val,
2562                             uint64_t Address, const void *Decoder){
2563   Inst.addOperand(MCOperand::CreateImm(Val << 1));
2564   return Success;
2565 }
2566 
2567 static DecodeStatus DecodeThumbBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
2568                                        uint64_t Address, const void *Decoder){
2569   Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
2570   return Success;
2571 }
2572 
2573 static DecodeStatus DecodeMemBarrierOption(llvm::MCInst &Inst, unsigned Val,
2574                                    uint64_t Address, const void *Decoder) {
2575   switch (Val) {
2576   default:
2577     return Fail;
2578   case 0xF: // SY
2579   case 0xE: // ST
2580   case 0xB: // ISH
2581   case 0xA: // ISHST
2582   case 0x7: // NSH
2583   case 0x6: // NSHST
2584   case 0x3: // OSH
2585   case 0x2: // OSHST
2586     break;
2587   }
2588 
2589   Inst.addOperand(MCOperand::CreateImm(Val));
2590   return Success;
2591 }
2592 
2593 static DecodeStatus DecodeMSRMask(llvm::MCInst &Inst, unsigned Val,
2594                           uint64_t Address, const void *Decoder) {
2595   if (!Val) return Fail;
2596   Inst.addOperand(MCOperand::CreateImm(Val));
2597   return Success;
2598 }
2599 
2600 static DecodeStatus DecodeDoubleRegLoad(llvm::MCInst &Inst, unsigned Insn,
2601                                         uint64_t Address, const void *Decoder) {
2602   DecodeStatus S = Success;
2603 
2604   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2605   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2606   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
2607 
2608   if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return Fail;
2609 
2610   CHECK(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
2611   CHECK(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder));
2612   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2613   CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
2614 
2615   return S;
2616 }
2617 
2618 
2619 static DecodeStatus DecodeDoubleRegStore(llvm::MCInst &Inst, unsigned Insn,
2620                                          uint64_t Address, const void *Decoder){
2621   DecodeStatus S = Success;
2622 
2623   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2624   unsigned Rt = fieldFromInstruction32(Insn, 0, 4);
2625   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2626   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
2627 
2628   CHECK(S, DecoderGPRRegisterClass(Inst, Rd, Address, Decoder));
2629 
2630   if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return Fail;
2631   if (Rd == Rn || Rd == Rt || Rd == Rt+1) return Fail;
2632 
2633   CHECK(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
2634   CHECK(S, DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder));
2635   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2636   CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
2637 
2638   return S;
2639 }
2640 
2641 static DecodeStatus DecodeSTRPreImm(llvm::MCInst &Inst, unsigned Insn,
2642                             uint64_t Address, const void *Decoder) {
2643   DecodeStatus S = Success;
2644 
2645   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2646   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2647   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
2648   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
2649   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
2650   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
2651 
2652   if (Rn == 0xF || Rn == Rt) return Unpredictable; // UNPREDICTABLE
2653 
2654   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2655   CHECK(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
2656   CHECK(S, DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder));
2657   CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
2658 
2659   return S;
2660 }
2661 
2662 static DecodeStatus DecodeSTRPreReg(llvm::MCInst &Inst, unsigned Insn,
2663                             uint64_t Address, const void *Decoder) {
2664   DecodeStatus S = Success;
2665 
2666   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2667   unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2668   unsigned imm = fieldFromInstruction32(Insn, 0, 12);
2669   imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
2670   imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
2671   unsigned pred = fieldFromInstruction32(Insn, 28, 4);
2672 
2673   if (Rn == 0xF || Rn == Rt) return Unpredictable; // UNPREDICTABLE
2674 
2675   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2676   CHECK(S, DecodeGPRRegisterClass(Inst, Rt, Address, Decoder));
2677   CHECK(S, DecodeSORegMemOperand(Inst, imm, Address, Decoder));
2678   CHECK(S, DecodePredicateOperand(Inst, pred, Address, Decoder));
2679 
2680   return S;
2681 }
2682 
2683 static DecodeStatus DecodeVLD1LN(llvm::MCInst &Inst, unsigned Insn,
2684                          uint64_t Address, const void *Decoder) {
2685   DecodeStatus S = Success;
2686 
2687   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2688   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2689   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2690   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2691   unsigned size = fieldFromInstruction32(Insn, 10, 2);
2692 
2693   unsigned align = 0;
2694   unsigned index = 0;
2695   switch (size) {
2696     default:
2697       return Fail;
2698     case 0:
2699       if (fieldFromInstruction32(Insn, 4, 1))
2700         return Fail; // UNDEFINED
2701       index = fieldFromInstruction32(Insn, 5, 3);
2702       break;
2703     case 1:
2704       if (fieldFromInstruction32(Insn, 5, 1))
2705         return Fail; // UNDEFINED
2706       index = fieldFromInstruction32(Insn, 6, 2);
2707       if (fieldFromInstruction32(Insn, 4, 1))
2708         align = 2;
2709       break;
2710     case 2:
2711       if (fieldFromInstruction32(Insn, 6, 1))
2712         return Fail; // UNDEFINED
2713       index = fieldFromInstruction32(Insn, 7, 1);
2714       if (fieldFromInstruction32(Insn, 4, 2) != 0)
2715         align = 4;
2716   }
2717 
2718   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2719   if (Rm != 0xF) { // Writeback
2720     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2721   }
2722   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2723   Inst.addOperand(MCOperand::CreateImm(align));
2724   if (Rm != 0xF && Rm != 0xD) {
2725     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
2726   }
2727 
2728   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2729   Inst.addOperand(MCOperand::CreateImm(index));
2730 
2731   return S;
2732 }
2733 
2734 static DecodeStatus DecodeVST1LN(llvm::MCInst &Inst, unsigned Insn,
2735                          uint64_t Address, const void *Decoder) {
2736   DecodeStatus S = Success;
2737 
2738   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2739   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2740   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2741   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2742   unsigned size = fieldFromInstruction32(Insn, 10, 2);
2743 
2744   unsigned align = 0;
2745   unsigned index = 0;
2746   switch (size) {
2747     default:
2748       return Fail;
2749     case 0:
2750       if (fieldFromInstruction32(Insn, 4, 1))
2751         return Fail; // UNDEFINED
2752       index = fieldFromInstruction32(Insn, 5, 3);
2753       break;
2754     case 1:
2755       if (fieldFromInstruction32(Insn, 5, 1))
2756         return Fail; // UNDEFINED
2757       index = fieldFromInstruction32(Insn, 6, 2);
2758       if (fieldFromInstruction32(Insn, 4, 1))
2759         align = 2;
2760       break;
2761     case 2:
2762       if (fieldFromInstruction32(Insn, 6, 1))
2763         return Fail; // UNDEFINED
2764       index = fieldFromInstruction32(Insn, 7, 1);
2765       if (fieldFromInstruction32(Insn, 4, 2) != 0)
2766         align = 4;
2767   }
2768 
2769   if (Rm != 0xF) { // Writeback
2770     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2771   }
2772   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2773   Inst.addOperand(MCOperand::CreateImm(align));
2774   if (Rm != 0xF && Rm != 0xD) {
2775     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
2776   }
2777 
2778   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2779   Inst.addOperand(MCOperand::CreateImm(index));
2780 
2781   return S;
2782 }
2783 
2784 
2785 static DecodeStatus DecodeVLD2LN(llvm::MCInst &Inst, unsigned Insn,
2786                          uint64_t Address, const void *Decoder) {
2787   DecodeStatus S = Success;
2788 
2789   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2790   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2791   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2792   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2793   unsigned size = fieldFromInstruction32(Insn, 10, 2);
2794 
2795   unsigned align = 0;
2796   unsigned index = 0;
2797   unsigned inc = 1;
2798   switch (size) {
2799     default:
2800       return Fail;
2801     case 0:
2802       index = fieldFromInstruction32(Insn, 5, 3);
2803       if (fieldFromInstruction32(Insn, 4, 1))
2804         align = 2;
2805       break;
2806     case 1:
2807       index = fieldFromInstruction32(Insn, 6, 2);
2808       if (fieldFromInstruction32(Insn, 4, 1))
2809         align = 4;
2810       if (fieldFromInstruction32(Insn, 5, 1))
2811         inc = 2;
2812       break;
2813     case 2:
2814       if (fieldFromInstruction32(Insn, 5, 1))
2815         return Fail; // UNDEFINED
2816       index = fieldFromInstruction32(Insn, 7, 1);
2817       if (fieldFromInstruction32(Insn, 4, 1) != 0)
2818         align = 8;
2819       if (fieldFromInstruction32(Insn, 6, 1))
2820         inc = 2;
2821       break;
2822   }
2823 
2824   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2825   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
2826   if (Rm != 0xF) { // Writeback
2827     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2828   }
2829   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2830   Inst.addOperand(MCOperand::CreateImm(align));
2831   if (Rm != 0xF && Rm != 0xD) {
2832     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
2833   }
2834 
2835   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2836   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
2837   Inst.addOperand(MCOperand::CreateImm(index));
2838 
2839   return S;
2840 }
2841 
2842 static DecodeStatus DecodeVST2LN(llvm::MCInst &Inst, unsigned Insn,
2843                          uint64_t Address, const void *Decoder) {
2844   DecodeStatus S = Success;
2845 
2846   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2847   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2848   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2849   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2850   unsigned size = fieldFromInstruction32(Insn, 10, 2);
2851 
2852   unsigned align = 0;
2853   unsigned index = 0;
2854   unsigned inc = 1;
2855   switch (size) {
2856     default:
2857       return Fail;
2858     case 0:
2859       index = fieldFromInstruction32(Insn, 5, 3);
2860       if (fieldFromInstruction32(Insn, 4, 1))
2861         align = 2;
2862       break;
2863     case 1:
2864       index = fieldFromInstruction32(Insn, 6, 2);
2865       if (fieldFromInstruction32(Insn, 4, 1))
2866         align = 4;
2867       if (fieldFromInstruction32(Insn, 5, 1))
2868         inc = 2;
2869       break;
2870     case 2:
2871       if (fieldFromInstruction32(Insn, 5, 1))
2872         return Fail; // UNDEFINED
2873       index = fieldFromInstruction32(Insn, 7, 1);
2874       if (fieldFromInstruction32(Insn, 4, 1) != 0)
2875         align = 8;
2876       if (fieldFromInstruction32(Insn, 6, 1))
2877         inc = 2;
2878       break;
2879   }
2880 
2881   if (Rm != 0xF) { // Writeback
2882     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2883   }
2884   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2885   Inst.addOperand(MCOperand::CreateImm(align));
2886   if (Rm != 0xF && Rm != 0xD) {
2887     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
2888   }
2889 
2890   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2891   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
2892   Inst.addOperand(MCOperand::CreateImm(index));
2893 
2894   return S;
2895 }
2896 
2897 
2898 static DecodeStatus DecodeVLD3LN(llvm::MCInst &Inst, unsigned Insn,
2899                          uint64_t Address, const void *Decoder) {
2900   DecodeStatus S = Success;
2901 
2902   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2903   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2904   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2905   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2906   unsigned size = fieldFromInstruction32(Insn, 10, 2);
2907 
2908   unsigned align = 0;
2909   unsigned index = 0;
2910   unsigned inc = 1;
2911   switch (size) {
2912     default:
2913       return Fail;
2914     case 0:
2915       if (fieldFromInstruction32(Insn, 4, 1))
2916         return Fail; // UNDEFINED
2917       index = fieldFromInstruction32(Insn, 5, 3);
2918       break;
2919     case 1:
2920       if (fieldFromInstruction32(Insn, 4, 1))
2921         return Fail; // UNDEFINED
2922       index = fieldFromInstruction32(Insn, 6, 2);
2923       if (fieldFromInstruction32(Insn, 5, 1))
2924         inc = 2;
2925       break;
2926     case 2:
2927       if (fieldFromInstruction32(Insn, 4, 2))
2928         return Fail; // UNDEFINED
2929       index = fieldFromInstruction32(Insn, 7, 1);
2930       if (fieldFromInstruction32(Insn, 6, 1))
2931         inc = 2;
2932       break;
2933   }
2934 
2935   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2936   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
2937   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder));
2938 
2939   if (Rm != 0xF) { // Writeback
2940     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2941   }
2942   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2943   Inst.addOperand(MCOperand::CreateImm(align));
2944   if (Rm != 0xF && Rm != 0xD) {
2945     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
2946   }
2947 
2948   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
2949   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
2950   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder));
2951   Inst.addOperand(MCOperand::CreateImm(index));
2952 
2953   return S;
2954 }
2955 
2956 static DecodeStatus DecodeVST3LN(llvm::MCInst &Inst, unsigned Insn,
2957                          uint64_t Address, const void *Decoder) {
2958   DecodeStatus S = Success;
2959 
2960   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2961   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2962   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2963   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2964   unsigned size = fieldFromInstruction32(Insn, 10, 2);
2965 
2966   unsigned align = 0;
2967   unsigned index = 0;
2968   unsigned inc = 1;
2969   switch (size) {
2970     default:
2971       return Fail;
2972     case 0:
2973       if (fieldFromInstruction32(Insn, 4, 1))
2974         return Fail; // UNDEFINED
2975       index = fieldFromInstruction32(Insn, 5, 3);
2976       break;
2977     case 1:
2978       if (fieldFromInstruction32(Insn, 4, 1))
2979         return Fail; // UNDEFINED
2980       index = fieldFromInstruction32(Insn, 6, 2);
2981       if (fieldFromInstruction32(Insn, 5, 1))
2982         inc = 2;
2983       break;
2984     case 2:
2985       if (fieldFromInstruction32(Insn, 4, 2))
2986         return Fail; // UNDEFINED
2987       index = fieldFromInstruction32(Insn, 7, 1);
2988       if (fieldFromInstruction32(Insn, 6, 1))
2989         inc = 2;
2990       break;
2991   }
2992 
2993   if (Rm != 0xF) { // Writeback
2994     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2995   }
2996   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
2997   Inst.addOperand(MCOperand::CreateImm(align));
2998   if (Rm != 0xF && Rm != 0xD) {
2999     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
3000   }
3001 
3002   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
3003   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
3004   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder));
3005   Inst.addOperand(MCOperand::CreateImm(index));
3006 
3007   return S;
3008 }
3009 
3010 
3011 static DecodeStatus DecodeVLD4LN(llvm::MCInst &Inst, unsigned Insn,
3012                          uint64_t Address, const void *Decoder) {
3013   DecodeStatus S = Success;
3014 
3015   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3016   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3017   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3018   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3019   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3020 
3021   unsigned align = 0;
3022   unsigned index = 0;
3023   unsigned inc = 1;
3024   switch (size) {
3025     default:
3026       return Fail;
3027     case 0:
3028       if (fieldFromInstruction32(Insn, 4, 1))
3029         align = 4;
3030       index = fieldFromInstruction32(Insn, 5, 3);
3031       break;
3032     case 1:
3033       if (fieldFromInstruction32(Insn, 4, 1))
3034         align = 8;
3035       index = fieldFromInstruction32(Insn, 6, 2);
3036       if (fieldFromInstruction32(Insn, 5, 1))
3037         inc = 2;
3038       break;
3039     case 2:
3040       if (fieldFromInstruction32(Insn, 4, 2))
3041         align = 4 << fieldFromInstruction32(Insn, 4, 2);
3042       index = fieldFromInstruction32(Insn, 7, 1);
3043       if (fieldFromInstruction32(Insn, 6, 1))
3044         inc = 2;
3045       break;
3046   }
3047 
3048   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
3049   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
3050   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder));
3051   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder));
3052 
3053   if (Rm != 0xF) { // Writeback
3054     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
3055   }
3056   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
3057   Inst.addOperand(MCOperand::CreateImm(align));
3058   if (Rm != 0xF && Rm != 0xD) {
3059     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
3060   }
3061 
3062   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
3063   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
3064   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder));
3065   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder));
3066   Inst.addOperand(MCOperand::CreateImm(index));
3067 
3068   return S;
3069 }
3070 
3071 static DecodeStatus DecodeVST4LN(llvm::MCInst &Inst, unsigned Insn,
3072                          uint64_t Address, const void *Decoder) {
3073   DecodeStatus S = Success;
3074 
3075   unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
3076   unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
3077   unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
3078   Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
3079   unsigned size = fieldFromInstruction32(Insn, 10, 2);
3080 
3081   unsigned align = 0;
3082   unsigned index = 0;
3083   unsigned inc = 1;
3084   switch (size) {
3085     default:
3086       return Fail;
3087     case 0:
3088       if (fieldFromInstruction32(Insn, 4, 1))
3089         align = 4;
3090       index = fieldFromInstruction32(Insn, 5, 3);
3091       break;
3092     case 1:
3093       if (fieldFromInstruction32(Insn, 4, 1))
3094         align = 8;
3095       index = fieldFromInstruction32(Insn, 6, 2);
3096       if (fieldFromInstruction32(Insn, 5, 1))
3097         inc = 2;
3098       break;
3099     case 2:
3100       if (fieldFromInstruction32(Insn, 4, 2))
3101         align = 4 << fieldFromInstruction32(Insn, 4, 2);
3102       index = fieldFromInstruction32(Insn, 7, 1);
3103       if (fieldFromInstruction32(Insn, 6, 1))
3104         inc = 2;
3105       break;
3106   }
3107 
3108   if (Rm != 0xF) { // Writeback
3109     CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
3110   }
3111   CHECK(S, DecodeGPRRegisterClass(Inst, Rn, Address, Decoder));
3112   Inst.addOperand(MCOperand::CreateImm(align));
3113   if (Rm != 0xF && Rm != 0xD) {
3114     CHECK(S, DecodeGPRRegisterClass(Inst, Rm, Address, Decoder));
3115   }
3116 
3117   CHECK(S, DecodeDPRRegisterClass(Inst, Rd, Address, Decoder));
3118   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+inc, Address, Decoder));
3119   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+2*inc, Address, Decoder));
3120   CHECK(S, DecodeDPRRegisterClass(Inst, Rd+3*inc, Address, Decoder));
3121   Inst.addOperand(MCOperand::CreateImm(index));
3122 
3123   return S;
3124 }
3125 
3126