ARMDisassembler.cpp revision 1fb6673bc2f0a404f4f914bf381c627402ac7c6b
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// Forward declare these because the autogenerated code will reference them.
28// Definitions are further down.
29static bool DecodeGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
30                                   uint64_t Address, const void *Decoder);
31static bool DecodeGPRnopcRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
32                                   uint64_t Address, const void *Decoder);
33static bool DecodetGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
34                                   uint64_t Address, const void *Decoder);
35static bool DecodetcGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
36                                   uint64_t Address, const void *Decoder);
37static bool DecoderGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
38                                   uint64_t Address, const void *Decoder);
39static bool DecodeSPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
40                                   uint64_t Address, const void *Decoder);
41static bool DecodeDPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
42                                   uint64_t Address, const void *Decoder);
43static bool DecodeDPR_8RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
44                                   uint64_t Address, const void *Decoder);
45static bool DecodeDPR_VFP2RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
46                                   uint64_t Address, const void *Decoder);
47static bool DecodeQPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
48                                   uint64_t Address, const void *Decoder);
49
50static bool DecodePredicateOperand(llvm::MCInst &Inst, unsigned Val,
51                               uint64_t Address, const void *Decoder);
52static bool DecodeCCOutOperand(llvm::MCInst &Inst, unsigned Val,
53                               uint64_t Address, const void *Decoder);
54static bool DecodeSOImmOperand(llvm::MCInst &Inst, unsigned Val,
55                               uint64_t Address, const void *Decoder);
56static bool DecodeBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
57                               uint64_t Address, const void *Decoder);
58static bool DecodeRegListOperand(llvm::MCInst &Inst, unsigned Val,
59                               uint64_t Address, const void *Decoder);
60static bool DecodeSPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
61                               uint64_t Address, const void *Decoder);
62static bool DecodeDPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
63                               uint64_t Address, const void *Decoder);
64
65static bool DecodeBitfieldMaskOperand(llvm::MCInst &Inst, unsigned Insn,
66                               uint64_t Address, const void *Decoder);
67static bool DecodeCopMemInstruction(llvm::MCInst &Inst, unsigned Insn,
68                               uint64_t Address, const void *Decoder);
69static bool DecodeAddrMode2IdxInstruction(llvm::MCInst &Inst, unsigned Insn,
70                               uint64_t Address, const void *Decoder);
71static bool DecodeSORegMemOperand(llvm::MCInst &Inst, unsigned Insn,
72                               uint64_t Address, const void *Decoder);
73static bool DecodeAddrMode3Instruction(llvm::MCInst &Inst, unsigned Insn,
74                               uint64_t Address, const void *Decoder);
75static bool DecodeSORegImmOperand(llvm::MCInst &Inst, unsigned Insn,
76                               uint64_t Address, const void *Decoder);
77static bool DecodeSORegRegOperand(llvm::MCInst &Inst, unsigned Insn,
78                               uint64_t Address, const void *Decoder);
79
80static bool DecodeMemMultipleWritebackInstruction(llvm::MCInst & Inst,
81                                                  unsigned Insn,
82                                                  uint64_t Adddress,
83                                                  const void *Decoder);
84static bool DecodeSMLAInstruction(llvm::MCInst &Inst, unsigned Insn,
85                               uint64_t Address, const void *Decoder);
86static bool DecodeCPSInstruction(llvm::MCInst &Inst, unsigned Insn,
87                               uint64_t Address, const void *Decoder);
88static bool DecodeAddrModeImm12Operand(llvm::MCInst &Inst, unsigned Val,
89                               uint64_t Address, const void *Decoder);
90static bool DecodeAddrMode5Operand(llvm::MCInst &Inst, unsigned Val,
91                               uint64_t Address, const void *Decoder);
92static bool DecodeAddrMode7Operand(llvm::MCInst &Inst, unsigned Val,
93                               uint64_t Address, const void *Decoder);
94static bool DecodeBranchImmInstruction(llvm::MCInst &Inst, unsigned Insn,
95                               uint64_t Address, const void *Decoder);
96static bool DecodeVCVTImmOperand(llvm::MCInst &Inst, unsigned Val,
97                               uint64_t Address, const void *Decoder);
98static bool DecodeAddrMode6Operand(llvm::MCInst &Inst, unsigned Val,
99                               uint64_t Address, const void *Decoder);
100static bool DecodeVLDInstruction(llvm::MCInst &Inst, unsigned Val,
101                               uint64_t Address, const void *Decoder);
102static bool DecodeVSTInstruction(llvm::MCInst &Inst, unsigned Val,
103                               uint64_t Address, const void *Decoder);
104static bool DecodeVLD1DupInstruction(llvm::MCInst &Inst, unsigned Val,
105                               uint64_t Address, const void *Decoder);
106static bool DecodeVLD2DupInstruction(llvm::MCInst &Inst, unsigned Val,
107                               uint64_t Address, const void *Decoder);
108static bool DecodeVLD3DupInstruction(llvm::MCInst &Inst, unsigned Val,
109                               uint64_t Address, const void *Decoder);
110static bool DecodeVLD4DupInstruction(llvm::MCInst &Inst, unsigned Val,
111                               uint64_t Address, const void *Decoder);
112static bool DecodeNEONModImmInstruction(llvm::MCInst &Inst, unsigned Val,
113                               uint64_t Address, const void *Decoder);
114static bool DecodeVSHLMaxInstruction(llvm::MCInst &Inst, unsigned Val,
115                               uint64_t Address, const void *Decoder);
116static bool DecodeShiftRight8Imm(llvm::MCInst &Inst, unsigned Val,
117                               uint64_t Address, const void *Decoder);
118static bool DecodeShiftRight16Imm(llvm::MCInst &Inst, unsigned Val,
119                               uint64_t Address, const void *Decoder);
120static bool DecodeShiftRight32Imm(llvm::MCInst &Inst, unsigned Val,
121                               uint64_t Address, const void *Decoder);
122static bool DecodeShiftRight64Imm(llvm::MCInst &Inst, unsigned Val,
123                               uint64_t Address, const void *Decoder);
124static bool DecodeTBLInstruction(llvm::MCInst &Inst, unsigned Insn,
125                               uint64_t Address, const void *Decoder);
126static bool DecodeVFPfpImm(llvm::MCInst &Inst, unsigned Val,
127                               uint64_t Address, const void *Decoder);
128static bool DecodePostIdxReg(llvm::MCInst &Inst, unsigned Insn,
129                               uint64_t Address, const void *Decoder);
130static bool DecodeCoprocessor(llvm::MCInst &Inst, unsigned Insn,
131                               uint64_t Address, const void *Decoder);
132static bool DecodeAddrMode3Offset(llvm::MCInst &Inst, unsigned Insn,
133                               uint64_t Address, const void *Decoder);
134static bool DecodeMemBarrierOption(llvm::MCInst &Inst, unsigned Insn,
135                               uint64_t Address, const void *Decoder);
136static bool DecodeMSRMask(llvm::MCInst &Inst, unsigned Insn,
137                               uint64_t Address, const void *Decoder);
138static bool DecodeDoubleRegExclusive(llvm::MCInst &Inst, unsigned Insn,
139                               uint64_t Address, const void *Decoder);
140
141
142static bool DecodeThumbAddSpecialReg(llvm::MCInst &Inst, uint16_t Insn,
143                               uint64_t Address, const void *Decoder);
144static bool DecodeThumbBROperand(llvm::MCInst &Inst, unsigned Val,
145                               uint64_t Address, const void *Decoder);
146static bool DecodeT2BROperand(llvm::MCInst &Inst, unsigned Val,
147                               uint64_t Address, const void *Decoder);
148static bool DecodeThumbCmpBROperand(llvm::MCInst &Inst, unsigned Val,
149                               uint64_t Address, const void *Decoder);
150static bool DecodeThumbAddrModeRR(llvm::MCInst &Inst, unsigned Val,
151                               uint64_t Address, const void *Decoder);
152static bool DecodeThumbAddrModeIS(llvm::MCInst &Inst, unsigned Val,
153                               uint64_t Address, const void *Decoder);
154static bool DecodeThumbAddrModePC(llvm::MCInst &Inst, unsigned Val,
155                               uint64_t Address, const void *Decoder);
156static bool DecodeThumbAddrModeSP(llvm::MCInst &Inst, unsigned Val,
157                               uint64_t Address, const void *Decoder);
158static bool DecodeT2AddrModeSOReg(llvm::MCInst &Inst, unsigned Val,
159                               uint64_t Address, const void *Decoder);
160static bool DecodeT2LoadShift(llvm::MCInst &Inst, unsigned Val,
161                               uint64_t Address, const void *Decoder);
162static bool DecodeT2Imm8S4(llvm::MCInst &Inst, unsigned Val,
163                               uint64_t Address, const void *Decoder);
164static bool DecodeT2AddrModeImm8s4(llvm::MCInst &Inst, unsigned Val,
165                               uint64_t Address, const void *Decoder);
166static bool DecodeT2Imm8(llvm::MCInst &Inst, unsigned Val,
167                               uint64_t Address, const void *Decoder);
168static bool DecodeT2AddrModeImm8(llvm::MCInst &Inst, unsigned Val,
169                               uint64_t Address, const void *Decoder);
170static bool DecodeThumbAddSPImm(llvm::MCInst &Inst, uint16_t Val,
171                               uint64_t Address, const void *Decoder);
172static bool DecodeThumbAddSPReg(llvm::MCInst &Inst, uint16_t Insn,
173                                uint64_t Address, const void *Decoder);
174static bool DecodeThumbCPS(llvm::MCInst &Inst, uint16_t Insn,
175                                uint64_t Address, const void *Decoder);
176static bool DecodeThumbBLXOffset(llvm::MCInst &Inst, unsigned Insn,
177                                uint64_t Address, const void *Decoder);
178static bool DecodeT2AddrModeImm12(llvm::MCInst &Inst, unsigned Val,
179                                uint64_t Address, const void *Decoder);
180static bool DecodeThumbSRImm(llvm::MCInst &Inst, unsigned Val,
181                                uint64_t Address, const void *Decoder);
182static bool DecodeThumb2BCCInstruction(llvm::MCInst &Inst, unsigned Val,
183                                uint64_t Address, const void *Decoder);
184static bool DecodeT2SOImm(llvm::MCInst &Inst, unsigned Val,
185                                uint64_t Address, const void *Decoder);
186static bool DecodeThumbBCCTargetOperand(llvm::MCInst &Inst, unsigned Val,
187                                uint64_t Address, const void *Decoder);
188static bool DecodeThumbBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
189                                uint64_t Address, const void *Decoder);
190
191#include "ARMGenDisassemblerTables.inc"
192#include "ARMGenInstrInfo.inc"
193#include "ARMGenEDInfo.inc"
194
195using namespace llvm;
196
197static MCDisassembler *createARMDisassembler(const Target &T) {
198  return new ARMDisassembler;
199}
200
201static MCDisassembler *createThumbDisassembler(const Target &T) {
202  return new ThumbDisassembler;
203}
204
205EDInstInfo *ARMDisassembler::getEDInfo() const {
206  return instInfoARM;
207}
208
209EDInstInfo *ThumbDisassembler::getEDInfo() const {
210  return instInfoARM;
211}
212
213
214bool ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
215                                     const MemoryObject &Region,
216                                     uint64_t Address,raw_ostream &os) const {
217  uint8_t bytes[4];
218
219  // We want to read exactly 4 bytes of data.
220  if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1)
221    return false;
222
223  // Encoded as a small-endian 32-bit word in the stream.
224  uint32_t insn = (bytes[3] << 24) |
225                  (bytes[2] << 16) |
226                  (bytes[1] <<  8) |
227                  (bytes[0] <<  0);
228
229  // Calling the auto-generated decoder function.
230  bool result = decodeARMInstruction32(MI, insn, Address, this);
231  if (result) {
232    Size = 4;
233    return true;
234  }
235
236  // Instructions that are shared between ARM and Thumb modes.
237  // FIXME: This shouldn't really exist.  It's an artifact of the
238  // fact that we fail to encode a few instructions properly for Thumb.
239  MI.clear();
240  result = decodeCommonInstruction32(MI, insn, Address, this);
241  if (result) {
242    Size = 4;
243    return true;
244  }
245
246  // VFP and NEON instructions, similarly, are shared between ARM
247  // and Thumb modes.
248  MI.clear();
249  result = decodeVFPInstruction32(MI, insn, Address, this);
250  if (result) {
251    Size = 4;
252    return true;
253  }
254
255  MI.clear();
256  result = decodeNEONDataInstruction32(MI, insn, Address, this);
257  if (result) {
258    Size = 4;
259    // Add a fake predicate operand, because we share these instruction
260    // definitions with Thumb2 where these instructions are predicable.
261    if (!DecodePredicateOperand(MI, 0xE, Address, this)) return false;
262    return true;
263  }
264
265  MI.clear();
266  result = decodeNEONLoadStoreInstruction32(MI, insn, Address, this);
267  if (result) {
268    Size = 4;
269    // Add a fake predicate operand, because we share these instruction
270    // definitions with Thumb2 where these instructions are predicable.
271    if (!DecodePredicateOperand(MI, 0xE, Address, this)) return false;
272    return true;
273  }
274
275  MI.clear();
276  result = decodeNEONDupInstruction32(MI, insn, Address, this);
277  if (result) {
278    Size = 4;
279    // Add a fake predicate operand, because we share these instruction
280    // definitions with Thumb2 where these instructions are predicable.
281    if (!DecodePredicateOperand(MI, 0xE, Address, this)) return false;
282    return true;
283  }
284
285  MI.clear();
286
287  return false;
288}
289
290namespace llvm {
291extern MCInstrDesc ARMInsts[];
292}
293
294// Thumb1 instructions don't have explicit S bits.  Rather, they
295// implicitly set CPSR.  Since it's not represented in the encoding, the
296// auto-generated decoder won't inject the CPSR operand.  We need to fix
297// that as a post-pass.
298static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
299  const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
300  MCInst::iterator I = MI.begin();
301  for (unsigned i = 0, e = MI.size(); i < e; ++i, ++I) {
302    if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
303      MI.insert(I, MCOperand::CreateReg(InITBlock ? 0 : ARM::CPSR));
304      return;
305    }
306  }
307
308  if (OpInfo[MI.size()].isOptionalDef() &&
309      OpInfo[MI.size()].RegClass == ARM::CCRRegClassID)
310    MI.insert(MI.end(), MCOperand::CreateReg(InITBlock ? 0 : ARM::CPSR));
311}
312
313// Most Thumb instructions don't have explicit predicates in the
314// encoding, but rather get their predicates from IT context.  We need
315// to fix up the predicate operands using this context information as a
316// post-pass.
317void ThumbDisassembler::AddThumbPredicate(MCInst &MI) const {
318  // A few instructions actually have predicates encoded in them.  Don't
319  // try to overwrite it if we're seeing one of those.
320  switch (MI.getOpcode()) {
321    case ARM::tBcc:
322    case ARM::t2Bcc:
323      return;
324    default:
325      break;
326  }
327
328  // If we're in an IT block, base the predicate on that.  Otherwise,
329  // assume a predicate of AL.
330  unsigned CC;
331  if (!ITBlock.empty()) {
332    CC = ITBlock.back();
333    ITBlock.pop_back();
334  } else
335    CC = ARMCC::AL;
336
337  const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
338  MCInst::iterator I = MI.begin();
339  for (unsigned i = 0, e = MI.size(); i < e; ++i, ++I) {
340    if (OpInfo[i].isPredicate()) {
341      I = MI.insert(I, MCOperand::CreateImm(CC));
342      ++I;
343      if (CC == ARMCC::AL)
344        MI.insert(I, MCOperand::CreateReg(0));
345      else
346        MI.insert(I, MCOperand::CreateReg(ARM::CPSR));
347      return;
348    }
349  }
350
351  MI.insert(MI.end(), MCOperand::CreateImm(CC));
352  if (CC == ARMCC::AL)
353    MI.insert(MI.end(), MCOperand::CreateReg(0));
354  else
355    MI.insert(MI.end(), MCOperand::CreateReg(ARM::CPSR));
356}
357
358// Thumb VFP instructions are a special case.  Because we share their
359// encodings between ARM and Thumb modes, and they are predicable in ARM
360// mode, the auto-generated decoder will give them an (incorrect)
361// predicate operand.  We need to rewrite these operands based on the IT
362// context as a post-pass.
363void ThumbDisassembler::UpdateThumbVFPPredicate(MCInst &MI) const {
364  unsigned CC;
365  if (!ITBlock.empty()) {
366    CC = ITBlock.back();
367    ITBlock.pop_back();
368  } else
369    CC = ARMCC::AL;
370
371  const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
372  MCInst::iterator I = MI.begin();
373  for (unsigned i = 0, e = MI.size(); i < e; ++i, ++I) {
374    if (OpInfo[i].isPredicate() ) {
375      I->setImm(CC);
376      ++I;
377      if (CC == ARMCC::AL)
378        I->setReg(0);
379      else
380        I->setReg(ARM::CPSR);
381      return;
382    }
383  }
384}
385
386
387bool ThumbDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
388                                       const MemoryObject &Region,
389                                       uint64_t Address,raw_ostream &os) const {
390  uint8_t bytes[4];
391
392  // We want to read exactly 2 bytes of data.
393  if (Region.readBytes(Address, 2, (uint8_t*)bytes, NULL) == -1)
394    return false;
395
396  uint16_t insn16 = (bytes[1] << 8) | bytes[0];
397  bool result = decodeThumbInstruction16(MI, insn16, Address, this);
398  if (result) {
399    Size = 2;
400    bool InITBlock = !ITBlock.empty();
401    AddThumbPredicate(MI);
402    AddThumb1SBit(MI, InITBlock);
403    return true;
404  }
405
406  MI.clear();
407  result = decodeThumb2Instruction16(MI, insn16, Address, this);
408  if (result) {
409    Size = 2;
410    AddThumbPredicate(MI);
411
412    // If we find an IT instruction, we need to parse its condition
413    // code and mask operands so that we can apply them correctly
414    // to the subsequent instructions.
415    if (MI.getOpcode() == ARM::t2IT) {
416      unsigned firstcond = MI.getOperand(0).getImm();
417      uint32_t mask = MI.getOperand(1).getImm();
418      unsigned zeros = CountTrailingZeros_32(mask);
419      mask >>= zeros+1;
420
421      for (unsigned i = 0; i < 4 - (zeros+1); ++i) {
422        if (firstcond ^ (mask & 1))
423          ITBlock.push_back(firstcond ^ 1);
424        else
425          ITBlock.push_back(firstcond);
426        mask >>= 1;
427      }
428      ITBlock.push_back(firstcond);
429    }
430
431    return true;
432  }
433
434  // We want to read exactly 4 bytes of data.
435  if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1)
436    return false;
437
438  uint32_t insn32 = (bytes[3] <<  8) |
439                    (bytes[2] <<  0) |
440                    (bytes[1] << 24) |
441                    (bytes[0] << 16);
442  MI.clear();
443  result = decodeThumbInstruction32(MI, insn32, Address, this);
444  if (result) {
445    Size = 4;
446    bool InITBlock = ITBlock.size();
447    AddThumbPredicate(MI);
448    AddThumb1SBit(MI, InITBlock);
449    return true;
450  }
451
452  MI.clear();
453  result = decodeThumb2Instruction32(MI, insn32, Address, this);
454  if (result) {
455    Size = 4;
456    AddThumbPredicate(MI);
457    return true;
458  }
459
460  MI.clear();
461  result = decodeCommonInstruction32(MI, insn32, Address, this);
462  if (result) {
463    Size = 4;
464    AddThumbPredicate(MI);
465    return true;
466  }
467
468  MI.clear();
469  result = decodeVFPInstruction32(MI, insn32, Address, this);
470  if (result) {
471    Size = 4;
472    UpdateThumbVFPPredicate(MI);
473    return true;
474  }
475
476  MI.clear();
477  if (fieldFromInstruction32(insn32, 24, 4) == 0xF) {
478    uint32_t NEONDataInsn = insn32;
479    NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
480    NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
481    NEONDataInsn |= 0x12000000; // Set bits 28 and 25
482    result = decodeNEONDataInstruction32(MI, NEONDataInsn, Address, this);
483    if (result) {
484      Size = 4;
485      AddThumbPredicate(MI);
486      return true;
487    }
488  }
489
490  MI.clear();
491  result = decodeNEONLoadStoreInstruction32(MI, insn32, Address, this);
492  if (result) {
493    Size = 4;
494    AddThumbPredicate(MI);
495    return true;
496  }
497
498  MI.clear();
499  result = decodeNEONDupInstruction32(MI, insn32, Address, this);
500  if (result) {
501    Size = 4;
502    AddThumbPredicate(MI);
503    return true;
504  }
505
506  return false;
507}
508
509
510extern "C" void LLVMInitializeARMDisassembler() {
511  TargetRegistry::RegisterMCDisassembler(TheARMTarget,
512                                         createARMDisassembler);
513  TargetRegistry::RegisterMCDisassembler(TheThumbTarget,
514                                         createThumbDisassembler);
515}
516
517static const unsigned GPRDecoderTable[] = {
518  ARM::R0, ARM::R1, ARM::R2, ARM::R3,
519  ARM::R4, ARM::R5, ARM::R6, ARM::R7,
520  ARM::R8, ARM::R9, ARM::R10, ARM::R11,
521  ARM::R12, ARM::SP, ARM::LR, ARM::PC
522};
523
524static bool DecodeGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
525                                   uint64_t Address, const void *Decoder) {
526  if (RegNo > 15)
527    return false;
528
529  unsigned Register = GPRDecoderTable[RegNo];
530  Inst.addOperand(MCOperand::CreateReg(Register));
531  return true;
532}
533
534static bool DecodeGPRnopcRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
535                                       uint64_t Address, const void *Decoder) {
536  if (RegNo == 15) return false;
537  return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
538}
539
540static bool DecodetGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
541                                   uint64_t Address, const void *Decoder) {
542  if (RegNo > 7)
543    return false;
544  return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
545}
546
547static bool DecodetcGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
548                                   uint64_t Address, const void *Decoder) {
549  unsigned Register = 0;
550  switch (RegNo) {
551    case 0:
552      Register = ARM::R0;
553      break;
554    case 1:
555      Register = ARM::R1;
556      break;
557    case 2:
558      Register = ARM::R2;
559      break;
560    case 3:
561      Register = ARM::R3;
562      break;
563    case 9:
564      Register = ARM::R9;
565      break;
566    case 12:
567      Register = ARM::R12;
568      break;
569    default:
570      return false;
571    }
572
573  Inst.addOperand(MCOperand::CreateReg(Register));
574  return true;
575}
576
577static bool DecoderGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
578                                   uint64_t Address, const void *Decoder) {
579  if (RegNo == 13 || RegNo == 15) return false;
580  return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
581}
582
583static const unsigned SPRDecoderTable[] = {
584     ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
585     ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
586     ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
587    ARM::S12, ARM::S13, ARM::S14, ARM::S15,
588    ARM::S16, ARM::S17, ARM::S18, ARM::S19,
589    ARM::S20, ARM::S21, ARM::S22, ARM::S23,
590    ARM::S24, ARM::S25, ARM::S26, ARM::S27,
591    ARM::S28, ARM::S29, ARM::S30, ARM::S31
592};
593
594static bool DecodeSPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
595                                   uint64_t Address, const void *Decoder) {
596  if (RegNo > 31)
597    return false;
598
599  unsigned Register = SPRDecoderTable[RegNo];
600  Inst.addOperand(MCOperand::CreateReg(Register));
601  return true;
602}
603
604static const unsigned DPRDecoderTable[] = {
605     ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
606     ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
607     ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
608    ARM::D12, ARM::D13, ARM::D14, ARM::D15,
609    ARM::D16, ARM::D17, ARM::D18, ARM::D19,
610    ARM::D20, ARM::D21, ARM::D22, ARM::D23,
611    ARM::D24, ARM::D25, ARM::D26, ARM::D27,
612    ARM::D28, ARM::D29, ARM::D30, ARM::D31
613};
614
615static bool DecodeDPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
616                                   uint64_t Address, const void *Decoder) {
617  if (RegNo > 31)
618    return false;
619
620  unsigned Register = DPRDecoderTable[RegNo];
621  Inst.addOperand(MCOperand::CreateReg(Register));
622  return true;
623}
624
625static bool DecodeDPR_8RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
626                                   uint64_t Address, const void *Decoder) {
627  if (RegNo > 7)
628    return false;
629  return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
630}
631
632static bool DecodeDPR_VFP2RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
633                                   uint64_t Address, const void *Decoder) {
634  if (RegNo > 15)
635    return false;
636  return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
637}
638
639static const unsigned QPRDecoderTable[] = {
640     ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
641     ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
642     ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
643    ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
644};
645
646
647static bool DecodeQPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
648                                   uint64_t Address, const void *Decoder) {
649  if (RegNo > 31)
650    return false;
651  RegNo >>= 1;
652
653  unsigned Register = QPRDecoderTable[RegNo];
654  Inst.addOperand(MCOperand::CreateReg(Register));
655  return true;
656}
657
658static bool DecodePredicateOperand(llvm::MCInst &Inst, unsigned Val,
659                               uint64_t Address, const void *Decoder) {
660  if (Val == 0xF) return false;
661  // AL predicate is not allowed on Thumb1 branches.
662  if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
663    return false;
664  Inst.addOperand(MCOperand::CreateImm(Val));
665  if (Val == ARMCC::AL) {
666    Inst.addOperand(MCOperand::CreateReg(0));
667  } else
668    Inst.addOperand(MCOperand::CreateReg(ARM::CPSR));
669  return true;
670}
671
672static bool DecodeCCOutOperand(llvm::MCInst &Inst, unsigned Val,
673                               uint64_t Address, const void *Decoder) {
674  if (Val)
675    Inst.addOperand(MCOperand::CreateReg(ARM::CPSR));
676  else
677    Inst.addOperand(MCOperand::CreateReg(0));
678  return true;
679}
680
681static bool DecodeSOImmOperand(llvm::MCInst &Inst, unsigned Val,
682                               uint64_t Address, const void *Decoder) {
683  uint32_t imm = Val & 0xFF;
684  uint32_t rot = (Val & 0xF00) >> 7;
685  uint32_t rot_imm = (imm >> rot) | (imm << (32-rot));
686  Inst.addOperand(MCOperand::CreateImm(rot_imm));
687  return true;
688}
689
690static bool DecodeBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
691                               uint64_t Address, const void *Decoder) {
692  Val <<= 2;
693  Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(Val)));
694  return true;
695}
696
697static bool DecodeSORegImmOperand(llvm::MCInst &Inst, unsigned Val,
698                               uint64_t Address, const void *Decoder) {
699
700  unsigned Rm = fieldFromInstruction32(Val, 0, 4);
701  unsigned type = fieldFromInstruction32(Val, 5, 2);
702  unsigned imm = fieldFromInstruction32(Val, 7, 5);
703
704  // Register-immediate
705  if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
706
707  ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
708  switch (type) {
709    case 0:
710      Shift = ARM_AM::lsl;
711      break;
712    case 1:
713      Shift = ARM_AM::lsr;
714      break;
715    case 2:
716      Shift = ARM_AM::asr;
717      break;
718    case 3:
719      Shift = ARM_AM::ror;
720      break;
721  }
722
723  if (Shift == ARM_AM::ror && imm == 0)
724    Shift = ARM_AM::rrx;
725
726  unsigned Op = Shift | (imm << 3);
727  Inst.addOperand(MCOperand::CreateImm(Op));
728
729  return true;
730}
731
732static bool DecodeSORegRegOperand(llvm::MCInst &Inst, unsigned Val,
733                               uint64_t Address, const void *Decoder) {
734
735  unsigned Rm = fieldFromInstruction32(Val, 0, 4);
736  unsigned type = fieldFromInstruction32(Val, 5, 2);
737  unsigned Rs = fieldFromInstruction32(Val, 8, 4);
738
739  // Register-register
740  if (!DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)) return false;
741  if (!DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)) return false;
742
743  ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
744  switch (type) {
745    case 0:
746      Shift = ARM_AM::lsl;
747      break;
748    case 1:
749      Shift = ARM_AM::lsr;
750      break;
751    case 2:
752      Shift = ARM_AM::asr;
753      break;
754    case 3:
755      Shift = ARM_AM::ror;
756      break;
757  }
758
759  Inst.addOperand(MCOperand::CreateImm(Shift));
760
761  return true;
762}
763
764static bool DecodeRegListOperand(llvm::MCInst &Inst, unsigned Val,
765                                 uint64_t Address, const void *Decoder) {
766  // Empty register lists are not allowed.
767  if (CountPopulation_32(Val) == 0) return false;
768  for (unsigned i = 0; i < 16; ++i) {
769    if (Val & (1 << i)) {
770      if (!DecodeGPRRegisterClass(Inst, i, Address, Decoder)) return false;
771    }
772  }
773
774  return true;
775}
776
777static bool DecodeSPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
778                                 uint64_t Address, const void *Decoder) {
779  unsigned Vd = fieldFromInstruction32(Val, 8, 4);
780  unsigned regs = Val & 0xFF;
781
782  if (!DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)) return false;
783  for (unsigned i = 0; i < (regs - 1); ++i) {
784    if (!DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)) return false;
785  }
786
787  return true;
788}
789
790static bool DecodeDPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
791                                 uint64_t Address, const void *Decoder) {
792  unsigned Vd = fieldFromInstruction32(Val, 8, 4);
793  unsigned regs = (Val & 0xFF) / 2;
794
795  if (!DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)) return false;
796  for (unsigned i = 0; i < (regs - 1); ++i) {
797    if (!DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)) return false;
798  }
799
800  return true;
801}
802
803static bool DecodeBitfieldMaskOperand(llvm::MCInst &Inst, unsigned Val,
804                                      uint64_t Address, const void *Decoder) {
805  // This operand encodes a mask of contiguous zeros between a specified MSB
806  // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
807  // the mask of all bits LSB-and-lower, and then xor them to create
808  // the mask of that's all ones on [msb, lsb].  Finally we not it to
809  // create the final mask.
810  unsigned msb = fieldFromInstruction32(Val, 5, 5);
811  unsigned lsb = fieldFromInstruction32(Val, 0, 5);
812  uint32_t msb_mask = (1 << (msb+1)) - 1;
813  uint32_t lsb_mask = (1 << lsb) - 1;
814  Inst.addOperand(MCOperand::CreateImm(~(msb_mask ^ lsb_mask)));
815  return true;
816}
817
818static bool DecodeCopMemInstruction(llvm::MCInst &Inst, unsigned Insn,
819                                  uint64_t Address, const void *Decoder) {
820  unsigned pred = fieldFromInstruction32(Insn, 28, 4);
821  unsigned CRd = fieldFromInstruction32(Insn, 12, 4);
822  unsigned coproc = fieldFromInstruction32(Insn, 8, 4);
823  unsigned imm = fieldFromInstruction32(Insn, 0, 8);
824  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
825  unsigned U = fieldFromInstruction32(Insn, 23, 1);
826
827  switch (Inst.getOpcode()) {
828    case ARM::LDC_OFFSET:
829    case ARM::LDC_PRE:
830    case ARM::LDC_POST:
831    case ARM::LDC_OPTION:
832    case ARM::LDCL_OFFSET:
833    case ARM::LDCL_PRE:
834    case ARM::LDCL_POST:
835    case ARM::LDCL_OPTION:
836    case ARM::STC_OFFSET:
837    case ARM::STC_PRE:
838    case ARM::STC_POST:
839    case ARM::STC_OPTION:
840    case ARM::STCL_OFFSET:
841    case ARM::STCL_PRE:
842    case ARM::STCL_POST:
843    case ARM::STCL_OPTION:
844      if (coproc == 0xA || coproc == 0xB)
845        return false;
846      break;
847    default:
848      break;
849  }
850
851  Inst.addOperand(MCOperand::CreateImm(coproc));
852  Inst.addOperand(MCOperand::CreateImm(CRd));
853  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
854  switch (Inst.getOpcode()) {
855    case ARM::LDC_OPTION:
856    case ARM::LDCL_OPTION:
857    case ARM::LDC2_OPTION:
858    case ARM::LDC2L_OPTION:
859    case ARM::STC_OPTION:
860    case ARM::STCL_OPTION:
861    case ARM::STC2_OPTION:
862    case ARM::STC2L_OPTION:
863    case ARM::LDCL_POST:
864    case ARM::STCL_POST:
865      break;
866    default:
867      Inst.addOperand(MCOperand::CreateReg(0));
868      break;
869  }
870
871  unsigned P = fieldFromInstruction32(Insn, 24, 1);
872  unsigned W = fieldFromInstruction32(Insn, 21, 1);
873
874  bool writeback = (P == 0) || (W == 1);
875  unsigned idx_mode = 0;
876  if (P && writeback)
877    idx_mode = ARMII::IndexModePre;
878  else if (!P && writeback)
879    idx_mode = ARMII::IndexModePost;
880
881  switch (Inst.getOpcode()) {
882    case ARM::LDCL_POST:
883    case ARM::STCL_POST:
884      imm |= U << 8;
885    case ARM::LDC_OPTION:
886    case ARM::LDCL_OPTION:
887    case ARM::LDC2_OPTION:
888    case ARM::LDC2L_OPTION:
889    case ARM::STC_OPTION:
890    case ARM::STCL_OPTION:
891    case ARM::STC2_OPTION:
892    case ARM::STC2L_OPTION:
893      Inst.addOperand(MCOperand::CreateImm(imm));
894      break;
895    default:
896      if (U)
897        Inst.addOperand(MCOperand::CreateImm(
898            ARM_AM::getAM2Opc(ARM_AM::add, imm, ARM_AM::lsl, idx_mode)));
899      else
900        Inst.addOperand(MCOperand::CreateImm(
901            ARM_AM::getAM2Opc(ARM_AM::sub, imm, ARM_AM::lsl, idx_mode)));
902      break;
903  }
904
905  switch (Inst.getOpcode()) {
906    case ARM::LDC_OFFSET:
907    case ARM::LDC_PRE:
908    case ARM::LDC_POST:
909    case ARM::LDC_OPTION:
910    case ARM::LDCL_OFFSET:
911    case ARM::LDCL_PRE:
912    case ARM::LDCL_POST:
913    case ARM::LDCL_OPTION:
914    case ARM::STC_OFFSET:
915    case ARM::STC_PRE:
916    case ARM::STC_POST:
917    case ARM::STC_OPTION:
918    case ARM::STCL_OFFSET:
919    case ARM::STCL_PRE:
920    case ARM::STCL_POST:
921    case ARM::STCL_OPTION:
922      if (!DecodePredicateOperand(Inst, pred, Address, Decoder)) return false;
923      break;
924    default:
925      break;
926  }
927
928  return true;
929}
930
931static bool DecodeAddrMode2IdxInstruction(llvm::MCInst &Inst, unsigned Insn,
932                                  uint64_t Address, const void *Decoder) {
933  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
934  unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
935  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
936  unsigned imm = fieldFromInstruction32(Insn, 0, 12);
937  unsigned pred = fieldFromInstruction32(Insn, 28, 4);
938  unsigned reg = fieldFromInstruction32(Insn, 25, 1);
939  unsigned P = fieldFromInstruction32(Insn, 24, 1);
940  unsigned W = fieldFromInstruction32(Insn, 21, 1);
941
942  // On stores, the writeback operand precedes Rt.
943  switch (Inst.getOpcode()) {
944    case ARM::STR_POST_IMM:
945    case ARM::STR_POST_REG:
946    case ARM::STRB_POST_IMM:
947    case ARM::STRB_POST_REG:
948    case ARM::STRTr:
949    case ARM::STRTi:
950    case ARM::STRBT_POST_REG:
951    case ARM::STRBT_POST_IMM:
952      if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
953      break;
954    default:
955      break;
956  }
957
958  if (!DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)) return false;
959
960  // On loads, the writeback operand comes after Rt.
961  switch (Inst.getOpcode()) {
962    case ARM::LDR_POST_IMM:
963    case ARM::LDR_POST_REG:
964    case ARM::LDRB_POST_IMM:
965    case ARM::LDRB_POST_REG:
966    case ARM::LDR_PRE:
967    case ARM::LDRBT_POST_REG:
968    case ARM::LDRBT_POST_IMM:
969    case ARM::LDRT_POST_REG:
970    case ARM::LDRT_POST_IMM:
971      if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder))
972        return false;
973      break;
974    default:
975      break;
976  }
977
978  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
979
980  ARM_AM::AddrOpc Op = ARM_AM::add;
981  if (!fieldFromInstruction32(Insn, 23, 1))
982    Op = ARM_AM::sub;
983
984  bool writeback = (P == 0) || (W == 1);
985  unsigned idx_mode = 0;
986  if (P && writeback)
987    idx_mode = ARMII::IndexModePre;
988  else if (!P && writeback)
989    idx_mode = ARMII::IndexModePost;
990
991  if (writeback && (Rn == 15 || Rn == Rt)) return false; // UNPREDICTABLE
992
993  if (reg) {
994    if (!DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)) return false;
995    ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
996    switch( fieldFromInstruction32(Insn, 5, 2)) {
997      case 0:
998        Opc = ARM_AM::lsl;
999        break;
1000      case 1:
1001        Opc = ARM_AM::lsr;
1002        break;
1003      case 2:
1004        Opc = ARM_AM::asr;
1005        break;
1006      case 3:
1007        Opc = ARM_AM::ror;
1008        break;
1009      default:
1010        return false;
1011    }
1012    unsigned amt = fieldFromInstruction32(Insn, 7, 5);
1013    unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1014
1015    Inst.addOperand(MCOperand::CreateImm(imm));
1016  } else {
1017    Inst.addOperand(MCOperand::CreateReg(0));
1018    unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1019    Inst.addOperand(MCOperand::CreateImm(tmp));
1020  }
1021
1022  if (!DecodePredicateOperand(Inst, pred, Address, Decoder)) return false;
1023
1024  return true;
1025}
1026
1027static bool DecodeSORegMemOperand(llvm::MCInst &Inst, unsigned Val,
1028                                  uint64_t Address, const void *Decoder) {
1029  unsigned Rn = fieldFromInstruction32(Val, 13, 4);
1030  unsigned Rm = fieldFromInstruction32(Val,  0, 4);
1031  unsigned type = fieldFromInstruction32(Val, 5, 2);
1032  unsigned imm = fieldFromInstruction32(Val, 7, 5);
1033  unsigned U = fieldFromInstruction32(Val, 12, 1);
1034
1035  ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1036  switch (type) {
1037    case 0:
1038      ShOp = ARM_AM::lsl;
1039      break;
1040    case 1:
1041      ShOp = ARM_AM::lsr;
1042      break;
1043    case 2:
1044      ShOp = ARM_AM::asr;
1045      break;
1046    case 3:
1047      ShOp = ARM_AM::ror;
1048      break;
1049  }
1050
1051  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1052  if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
1053  unsigned shift;
1054  if (U)
1055    shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1056  else
1057    shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1058  Inst.addOperand(MCOperand::CreateImm(shift));
1059
1060  return true;
1061}
1062
1063static bool DecodeAddrMode3Instruction(llvm::MCInst &Inst, unsigned Insn,
1064                                  uint64_t Address, const void *Decoder) {
1065  unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
1066  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1067  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1068  unsigned type = fieldFromInstruction32(Insn, 22, 1);
1069  unsigned imm = fieldFromInstruction32(Insn, 8, 4);
1070  unsigned U = ((~fieldFromInstruction32(Insn, 23, 1)) & 1) << 8;
1071  unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1072  unsigned W = fieldFromInstruction32(Insn, 21, 1);
1073  unsigned P = fieldFromInstruction32(Insn, 24, 1);
1074
1075  bool writeback = (W == 1) | (P == 0);
1076  if (writeback) { // Writeback
1077    if (P)
1078      U |= ARMII::IndexModePre << 9;
1079    else
1080      U |= ARMII::IndexModePost << 9;
1081
1082    // On stores, the writeback operand precedes Rt.
1083    switch (Inst.getOpcode()) {
1084    case ARM::STRD:
1085    case ARM::STRD_PRE:
1086    case ARM::STRD_POST:
1087      if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder))
1088        return false;
1089      break;
1090    default:
1091      break;
1092    }
1093  }
1094
1095  if (!DecodeGPRRegisterClass(Inst, Rt, Address, Decoder))
1096    return false;
1097  switch (Inst.getOpcode()) {
1098    case ARM::STRD:
1099    case ARM::STRD_PRE:
1100    case ARM::STRD_POST:
1101    case ARM::LDRD:
1102    case ARM::LDRD_PRE:
1103    case ARM::LDRD_POST:
1104      if (!DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder))
1105        return false;
1106      break;
1107    default:
1108      break;
1109  }
1110
1111  if (writeback) {
1112    // On loads, the writeback operand comes after Rt.
1113    switch (Inst.getOpcode()) {
1114    case ARM::LDRD:
1115    case ARM::LDRD_PRE:
1116    case ARM::LDRD_POST:
1117    case ARM::LDRHTr:
1118    case ARM::LDRSBTr:
1119      if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder))
1120        return false;
1121      break;
1122    default:
1123      break;
1124    }
1125  }
1126
1127  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder))
1128    return false;
1129
1130  if (type) {
1131    Inst.addOperand(MCOperand::CreateReg(0));
1132    Inst.addOperand(MCOperand::CreateImm(U | (imm << 4) | Rm));
1133  } else {
1134    if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder))
1135      return false;
1136    Inst.addOperand(MCOperand::CreateImm(U));
1137  }
1138
1139  if (!DecodePredicateOperand(Inst, pred, Address, Decoder)) return false;
1140
1141  return true;
1142}
1143
1144static bool DecodeRFEInstruction(llvm::MCInst &Inst, unsigned Insn,
1145                                 uint64_t Address, const void *Decoder) {
1146  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1147  unsigned mode = fieldFromInstruction32(Insn, 23, 2);
1148
1149  switch (mode) {
1150    case 0:
1151      mode = ARM_AM::da;
1152      break;
1153    case 1:
1154      mode = ARM_AM::ia;
1155      break;
1156    case 2:
1157      mode = ARM_AM::db;
1158      break;
1159    case 3:
1160      mode = ARM_AM::ib;
1161      break;
1162  }
1163
1164  Inst.addOperand(MCOperand::CreateImm(mode));
1165  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1166
1167  return true;
1168}
1169
1170static bool DecodeMemMultipleWritebackInstruction(llvm::MCInst &Inst,
1171                                  unsigned Insn,
1172                                  uint64_t Address, const void *Decoder) {
1173  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1174  unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1175  unsigned reglist = fieldFromInstruction32(Insn, 0, 16);
1176
1177  if (pred == 0xF) {
1178    switch (Inst.getOpcode()) {
1179      case ARM::STMDA:
1180        Inst.setOpcode(ARM::RFEDA);
1181        break;
1182      case ARM::STMDA_UPD:
1183        Inst.setOpcode(ARM::RFEDA_UPD);
1184        break;
1185      case ARM::STMDB:
1186        Inst.setOpcode(ARM::RFEDB);
1187        break;
1188      case ARM::STMDB_UPD:
1189        Inst.setOpcode(ARM::RFEDB_UPD);
1190        break;
1191      case ARM::STMIA:
1192        Inst.setOpcode(ARM::RFEIA);
1193        break;
1194      case ARM::STMIA_UPD:
1195        Inst.setOpcode(ARM::RFEIA_UPD);
1196        break;
1197      case ARM::STMIB:
1198        Inst.setOpcode(ARM::RFEIB);
1199        break;
1200      case ARM::STMIB_UPD:
1201        Inst.setOpcode(ARM::RFEIB_UPD);
1202        break;
1203    }
1204    return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
1205  }
1206
1207  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)   ||
1208      !DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)   || // Tied
1209      !DecodePredicateOperand(Inst, pred, Address, Decoder) ||
1210      !DecodeRegListOperand(Inst, reglist, Address, Decoder))
1211    return false;
1212
1213  return true;
1214}
1215
1216static bool DecodeCPSInstruction(llvm::MCInst &Inst, unsigned Insn,
1217                                 uint64_t Address, const void *Decoder) {
1218  unsigned imod = fieldFromInstruction32(Insn, 18, 2);
1219  unsigned M = fieldFromInstruction32(Insn, 17, 1);
1220  unsigned iflags = fieldFromInstruction32(Insn, 6, 3);
1221  unsigned mode = fieldFromInstruction32(Insn, 0, 5);
1222
1223  // imod == '01' --> UNPREDICTABLE
1224  if (imod == 1) return false;
1225
1226  if (M && mode && imod && iflags) {
1227    Inst.setOpcode(ARM::CPS3p);
1228    Inst.addOperand(MCOperand::CreateImm(imod));
1229    Inst.addOperand(MCOperand::CreateImm(iflags));
1230    Inst.addOperand(MCOperand::CreateImm(mode));
1231    return true;
1232  } else if (!mode && !M) {
1233    Inst.setOpcode(ARM::CPS2p);
1234    Inst.addOperand(MCOperand::CreateImm(imod));
1235    Inst.addOperand(MCOperand::CreateImm(iflags));
1236    return true;
1237  } else if (!imod && !iflags && M) {
1238    Inst.setOpcode(ARM::CPS1p);
1239    Inst.addOperand(MCOperand::CreateImm(mode));
1240    return true;
1241  }
1242
1243  return false;
1244}
1245
1246static bool DecodeSMLAInstruction(llvm::MCInst &Inst, unsigned Insn,
1247                                 uint64_t Address, const void *Decoder) {
1248  unsigned Rd = fieldFromInstruction32(Insn, 16, 4);
1249  unsigned Rn = fieldFromInstruction32(Insn, 0, 4);
1250  unsigned Rm = fieldFromInstruction32(Insn, 8, 4);
1251  unsigned Ra = fieldFromInstruction32(Insn, 12, 4);
1252  unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1253
1254  if (pred == 0xF)
1255    return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
1256
1257  if (!DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder) ||
1258      !DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder) ||
1259      !DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder) ||
1260      !DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder))
1261    return false;
1262
1263  if (!DecodePredicateOperand(Inst, pred, Address, Decoder)) return false;
1264
1265  return true;
1266}
1267
1268static bool DecodeAddrModeImm12Operand(llvm::MCInst &Inst, unsigned Val,
1269                           uint64_t Address, const void *Decoder) {
1270  unsigned add = fieldFromInstruction32(Val, 12, 1);
1271  unsigned imm = fieldFromInstruction32(Val, 0, 12);
1272  unsigned Rn = fieldFromInstruction32(Val, 13, 4);
1273
1274  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder))
1275    return false;
1276
1277  if (!add) imm *= -1;
1278  if (imm == 0 && !add) imm = INT32_MIN;
1279  Inst.addOperand(MCOperand::CreateImm(imm));
1280
1281  return true;
1282}
1283
1284static bool DecodeAddrMode5Operand(llvm::MCInst &Inst, unsigned Val,
1285                                   uint64_t Address, const void *Decoder) {
1286  unsigned Rn = fieldFromInstruction32(Val, 9, 4);
1287  unsigned U = fieldFromInstruction32(Val, 8, 1);
1288  unsigned imm = fieldFromInstruction32(Val, 0, 8);
1289
1290  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder))
1291    return false;
1292
1293  if (U)
1294    Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
1295  else
1296    Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
1297
1298  return true;
1299}
1300
1301static bool DecodeAddrMode7Operand(llvm::MCInst &Inst, unsigned Val,
1302                                   uint64_t Address, const void *Decoder) {
1303  return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
1304}
1305
1306static bool DecodeBranchImmInstruction(llvm::MCInst &Inst, unsigned Insn,
1307                                   uint64_t Address, const void *Decoder) {
1308  unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1309  unsigned imm = fieldFromInstruction32(Insn, 0, 24) << 2;
1310
1311  if (pred == 0xF) {
1312    Inst.setOpcode(ARM::BLXi);
1313    imm |= fieldFromInstruction32(Insn, 24, 1) << 1;
1314    Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1315    return true;
1316  }
1317
1318  Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1319  if (!DecodePredicateOperand(Inst, pred, Address, Decoder)) return false;
1320
1321  return true;
1322}
1323
1324
1325static bool DecodeVCVTImmOperand(llvm::MCInst &Inst, unsigned Val,
1326                                 uint64_t Address, const void *Decoder) {
1327  Inst.addOperand(MCOperand::CreateImm(64 - Val));
1328  return true;
1329}
1330
1331static bool DecodeAddrMode6Operand(llvm::MCInst &Inst, unsigned Val,
1332                                   uint64_t Address, const void *Decoder) {
1333  unsigned Rm = fieldFromInstruction32(Val, 0, 4);
1334  unsigned align = fieldFromInstruction32(Val, 4, 2);
1335
1336  if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder))
1337    return false;
1338  if (!align)
1339    Inst.addOperand(MCOperand::CreateImm(0));
1340  else
1341    Inst.addOperand(MCOperand::CreateImm(4 << align));
1342
1343  return true;
1344}
1345
1346static bool DecodeVLDInstruction(llvm::MCInst &Inst, unsigned Insn,
1347                                   uint64_t Address, const void *Decoder) {
1348  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1349  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1350  unsigned wb = fieldFromInstruction32(Insn, 16, 4);
1351  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1352  Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
1353  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1354
1355  // First output register
1356  if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
1357
1358  // Second output register
1359  switch (Inst.getOpcode()) {
1360    case ARM::VLD1q8:
1361    case ARM::VLD1q16:
1362    case ARM::VLD1q32:
1363    case ARM::VLD1q64:
1364    case ARM::VLD1q8_UPD:
1365    case ARM::VLD1q16_UPD:
1366    case ARM::VLD1q32_UPD:
1367    case ARM::VLD1q64_UPD:
1368    case ARM::VLD1d8T:
1369    case ARM::VLD1d16T:
1370    case ARM::VLD1d32T:
1371    case ARM::VLD1d64T:
1372    case ARM::VLD1d8T_UPD:
1373    case ARM::VLD1d16T_UPD:
1374    case ARM::VLD1d32T_UPD:
1375    case ARM::VLD1d64T_UPD:
1376    case ARM::VLD1d8Q:
1377    case ARM::VLD1d16Q:
1378    case ARM::VLD1d32Q:
1379    case ARM::VLD1d64Q:
1380    case ARM::VLD1d8Q_UPD:
1381    case ARM::VLD1d16Q_UPD:
1382    case ARM::VLD1d32Q_UPD:
1383    case ARM::VLD1d64Q_UPD:
1384    case ARM::VLD2d8:
1385    case ARM::VLD2d16:
1386    case ARM::VLD2d32:
1387    case ARM::VLD2d8_UPD:
1388    case ARM::VLD2d16_UPD:
1389    case ARM::VLD2d32_UPD:
1390    case ARM::VLD2q8:
1391    case ARM::VLD2q16:
1392    case ARM::VLD2q32:
1393    case ARM::VLD2q8_UPD:
1394    case ARM::VLD2q16_UPD:
1395    case ARM::VLD2q32_UPD:
1396    case ARM::VLD3d8:
1397    case ARM::VLD3d16:
1398    case ARM::VLD3d32:
1399    case ARM::VLD3d8_UPD:
1400    case ARM::VLD3d16_UPD:
1401    case ARM::VLD3d32_UPD:
1402    case ARM::VLD4d8:
1403    case ARM::VLD4d16:
1404    case ARM::VLD4d32:
1405    case ARM::VLD4d8_UPD:
1406    case ARM::VLD4d16_UPD:
1407    case ARM::VLD4d32_UPD:
1408      if (!DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)) return false;
1409      break;
1410    case ARM::VLD2b8:
1411    case ARM::VLD2b16:
1412    case ARM::VLD2b32:
1413    case ARM::VLD2b8_UPD:
1414    case ARM::VLD2b16_UPD:
1415    case ARM::VLD2b32_UPD:
1416    case ARM::VLD3q8:
1417    case ARM::VLD3q16:
1418    case ARM::VLD3q32:
1419    case ARM::VLD3q8_UPD:
1420    case ARM::VLD3q16_UPD:
1421    case ARM::VLD3q32_UPD:
1422    case ARM::VLD4q8:
1423    case ARM::VLD4q16:
1424    case ARM::VLD4q32:
1425    case ARM::VLD4q8_UPD:
1426    case ARM::VLD4q16_UPD:
1427    case ARM::VLD4q32_UPD:
1428      if (!DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)) return false;
1429    default:
1430      break;
1431  }
1432
1433  // Third output register
1434  switch(Inst.getOpcode()) {
1435    case ARM::VLD1d8T:
1436    case ARM::VLD1d16T:
1437    case ARM::VLD1d32T:
1438    case ARM::VLD1d64T:
1439    case ARM::VLD1d8T_UPD:
1440    case ARM::VLD1d16T_UPD:
1441    case ARM::VLD1d32T_UPD:
1442    case ARM::VLD1d64T_UPD:
1443    case ARM::VLD1d8Q:
1444    case ARM::VLD1d16Q:
1445    case ARM::VLD1d32Q:
1446    case ARM::VLD1d64Q:
1447    case ARM::VLD1d8Q_UPD:
1448    case ARM::VLD1d16Q_UPD:
1449    case ARM::VLD1d32Q_UPD:
1450    case ARM::VLD1d64Q_UPD:
1451    case ARM::VLD2q8:
1452    case ARM::VLD2q16:
1453    case ARM::VLD2q32:
1454    case ARM::VLD2q8_UPD:
1455    case ARM::VLD2q16_UPD:
1456    case ARM::VLD2q32_UPD:
1457    case ARM::VLD3d8:
1458    case ARM::VLD3d16:
1459    case ARM::VLD3d32:
1460    case ARM::VLD3d8_UPD:
1461    case ARM::VLD3d16_UPD:
1462    case ARM::VLD3d32_UPD:
1463    case ARM::VLD4d8:
1464    case ARM::VLD4d16:
1465    case ARM::VLD4d32:
1466    case ARM::VLD4d8_UPD:
1467    case ARM::VLD4d16_UPD:
1468    case ARM::VLD4d32_UPD:
1469      if (!DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)) return false;
1470      break;
1471    case ARM::VLD3q8:
1472    case ARM::VLD3q16:
1473    case ARM::VLD3q32:
1474    case ARM::VLD3q8_UPD:
1475    case ARM::VLD3q16_UPD:
1476    case ARM::VLD3q32_UPD:
1477    case ARM::VLD4q8:
1478    case ARM::VLD4q16:
1479    case ARM::VLD4q32:
1480    case ARM::VLD4q8_UPD:
1481    case ARM::VLD4q16_UPD:
1482    case ARM::VLD4q32_UPD:
1483      if (!DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)) return false;
1484      break;
1485    default:
1486      break;
1487  }
1488
1489  // Fourth output register
1490  switch (Inst.getOpcode()) {
1491    case ARM::VLD1d8Q:
1492    case ARM::VLD1d16Q:
1493    case ARM::VLD1d32Q:
1494    case ARM::VLD1d64Q:
1495    case ARM::VLD1d8Q_UPD:
1496    case ARM::VLD1d16Q_UPD:
1497    case ARM::VLD1d32Q_UPD:
1498    case ARM::VLD1d64Q_UPD:
1499    case ARM::VLD2q8:
1500    case ARM::VLD2q16:
1501    case ARM::VLD2q32:
1502    case ARM::VLD2q8_UPD:
1503    case ARM::VLD2q16_UPD:
1504    case ARM::VLD2q32_UPD:
1505    case ARM::VLD4d8:
1506    case ARM::VLD4d16:
1507    case ARM::VLD4d32:
1508    case ARM::VLD4d8_UPD:
1509    case ARM::VLD4d16_UPD:
1510    case ARM::VLD4d32_UPD:
1511      if (!DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)) return false;
1512      break;
1513    case ARM::VLD4q8:
1514    case ARM::VLD4q16:
1515    case ARM::VLD4q32:
1516    case ARM::VLD4q8_UPD:
1517    case ARM::VLD4q16_UPD:
1518    case ARM::VLD4q32_UPD:
1519      if (!DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)) return false;
1520      break;
1521    default:
1522      break;
1523  }
1524
1525  // Writeback operand
1526  switch (Inst.getOpcode()) {
1527    case ARM::VLD1d8_UPD:
1528    case ARM::VLD1d16_UPD:
1529    case ARM::VLD1d32_UPD:
1530    case ARM::VLD1d64_UPD:
1531    case ARM::VLD1q8_UPD:
1532    case ARM::VLD1q16_UPD:
1533    case ARM::VLD1q32_UPD:
1534    case ARM::VLD1q64_UPD:
1535    case ARM::VLD1d8T_UPD:
1536    case ARM::VLD1d16T_UPD:
1537    case ARM::VLD1d32T_UPD:
1538    case ARM::VLD1d64T_UPD:
1539    case ARM::VLD1d8Q_UPD:
1540    case ARM::VLD1d16Q_UPD:
1541    case ARM::VLD1d32Q_UPD:
1542    case ARM::VLD1d64Q_UPD:
1543    case ARM::VLD2d8_UPD:
1544    case ARM::VLD2d16_UPD:
1545    case ARM::VLD2d32_UPD:
1546    case ARM::VLD2q8_UPD:
1547    case ARM::VLD2q16_UPD:
1548    case ARM::VLD2q32_UPD:
1549    case ARM::VLD2b8_UPD:
1550    case ARM::VLD2b16_UPD:
1551    case ARM::VLD2b32_UPD:
1552    case ARM::VLD3d8_UPD:
1553    case ARM::VLD3d16_UPD:
1554    case ARM::VLD3d32_UPD:
1555    case ARM::VLD3q8_UPD:
1556    case ARM::VLD3q16_UPD:
1557    case ARM::VLD3q32_UPD:
1558    case ARM::VLD4d8_UPD:
1559    case ARM::VLD4d16_UPD:
1560    case ARM::VLD4d32_UPD:
1561    case ARM::VLD4q8_UPD:
1562    case ARM::VLD4q16_UPD:
1563    case ARM::VLD4q32_UPD:
1564      if (!DecodeGPRRegisterClass(Inst, wb, Address, Decoder)) return false;
1565      break;
1566    default:
1567      break;
1568  }
1569
1570  // AddrMode6 Base (register+alignment)
1571  if (!DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)) return false;
1572
1573  // AddrMode6 Offset (register)
1574  if (Rm == 0xD)
1575    Inst.addOperand(MCOperand::CreateReg(0));
1576  else if (Rm != 0xF) {
1577    if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder))
1578      return false;
1579  }
1580
1581  return true;
1582}
1583
1584static bool DecodeVSTInstruction(llvm::MCInst &Inst, unsigned Insn,
1585                                 uint64_t Address, const void *Decoder) {
1586  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1587  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1588  unsigned wb = fieldFromInstruction32(Insn, 16, 4);
1589  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1590  Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
1591  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1592
1593  // Writeback Operand
1594  switch (Inst.getOpcode()) {
1595    case ARM::VST1d8_UPD:
1596    case ARM::VST1d16_UPD:
1597    case ARM::VST1d32_UPD:
1598    case ARM::VST1d64_UPD:
1599    case ARM::VST1q8_UPD:
1600    case ARM::VST1q16_UPD:
1601    case ARM::VST1q32_UPD:
1602    case ARM::VST1q64_UPD:
1603    case ARM::VST1d8T_UPD:
1604    case ARM::VST1d16T_UPD:
1605    case ARM::VST1d32T_UPD:
1606    case ARM::VST1d64T_UPD:
1607    case ARM::VST1d8Q_UPD:
1608    case ARM::VST1d16Q_UPD:
1609    case ARM::VST1d32Q_UPD:
1610    case ARM::VST1d64Q_UPD:
1611    case ARM::VST2d8_UPD:
1612    case ARM::VST2d16_UPD:
1613    case ARM::VST2d32_UPD:
1614    case ARM::VST2q8_UPD:
1615    case ARM::VST2q16_UPD:
1616    case ARM::VST2q32_UPD:
1617    case ARM::VST2b8_UPD:
1618    case ARM::VST2b16_UPD:
1619    case ARM::VST2b32_UPD:
1620    case ARM::VST3d8_UPD:
1621    case ARM::VST3d16_UPD:
1622    case ARM::VST3d32_UPD:
1623    case ARM::VST3q8_UPD:
1624    case ARM::VST3q16_UPD:
1625    case ARM::VST3q32_UPD:
1626    case ARM::VST4d8_UPD:
1627    case ARM::VST4d16_UPD:
1628    case ARM::VST4d32_UPD:
1629    case ARM::VST4q8_UPD:
1630    case ARM::VST4q16_UPD:
1631    case ARM::VST4q32_UPD:
1632      if (!DecodeGPRRegisterClass(Inst, wb, Address, Decoder))
1633        return false;
1634      break;
1635    default:
1636      break;
1637  }
1638
1639  // AddrMode6 Base (register+alignment)
1640  if (!DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)) return false;
1641
1642  // AddrMode6 Offset (register)
1643  if (Rm == 0xD)
1644    Inst.addOperand(MCOperand::CreateReg(0));
1645  else if (Rm != 0xF) {
1646    if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
1647  }
1648
1649  // First input register
1650  if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
1651
1652  // Second input register
1653  switch (Inst.getOpcode()) {
1654    case ARM::VST1q8:
1655    case ARM::VST1q16:
1656    case ARM::VST1q32:
1657    case ARM::VST1q64:
1658    case ARM::VST1q8_UPD:
1659    case ARM::VST1q16_UPD:
1660    case ARM::VST1q32_UPD:
1661    case ARM::VST1q64_UPD:
1662    case ARM::VST1d8T:
1663    case ARM::VST1d16T:
1664    case ARM::VST1d32T:
1665    case ARM::VST1d64T:
1666    case ARM::VST1d8T_UPD:
1667    case ARM::VST1d16T_UPD:
1668    case ARM::VST1d32T_UPD:
1669    case ARM::VST1d64T_UPD:
1670    case ARM::VST1d8Q:
1671    case ARM::VST1d16Q:
1672    case ARM::VST1d32Q:
1673    case ARM::VST1d64Q:
1674    case ARM::VST1d8Q_UPD:
1675    case ARM::VST1d16Q_UPD:
1676    case ARM::VST1d32Q_UPD:
1677    case ARM::VST1d64Q_UPD:
1678    case ARM::VST2d8:
1679    case ARM::VST2d16:
1680    case ARM::VST2d32:
1681    case ARM::VST2d8_UPD:
1682    case ARM::VST2d16_UPD:
1683    case ARM::VST2d32_UPD:
1684    case ARM::VST2q8:
1685    case ARM::VST2q16:
1686    case ARM::VST2q32:
1687    case ARM::VST2q8_UPD:
1688    case ARM::VST2q16_UPD:
1689    case ARM::VST2q32_UPD:
1690    case ARM::VST3d8:
1691    case ARM::VST3d16:
1692    case ARM::VST3d32:
1693    case ARM::VST3d8_UPD:
1694    case ARM::VST3d16_UPD:
1695    case ARM::VST3d32_UPD:
1696    case ARM::VST4d8:
1697    case ARM::VST4d16:
1698    case ARM::VST4d32:
1699    case ARM::VST4d8_UPD:
1700    case ARM::VST4d16_UPD:
1701    case ARM::VST4d32_UPD:
1702      if (!DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)) return false;
1703      break;
1704    case ARM::VST2b8:
1705    case ARM::VST2b16:
1706    case ARM::VST2b32:
1707    case ARM::VST2b8_UPD:
1708    case ARM::VST2b16_UPD:
1709    case ARM::VST2b32_UPD:
1710    case ARM::VST3q8:
1711    case ARM::VST3q16:
1712    case ARM::VST3q32:
1713    case ARM::VST3q8_UPD:
1714    case ARM::VST3q16_UPD:
1715    case ARM::VST3q32_UPD:
1716    case ARM::VST4q8:
1717    case ARM::VST4q16:
1718    case ARM::VST4q32:
1719    case ARM::VST4q8_UPD:
1720    case ARM::VST4q16_UPD:
1721    case ARM::VST4q32_UPD:
1722      if (!DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)) return false;
1723      break;
1724    default:
1725      break;
1726  }
1727
1728  // Third input register
1729  switch (Inst.getOpcode()) {
1730    case ARM::VST1d8T:
1731    case ARM::VST1d16T:
1732    case ARM::VST1d32T:
1733    case ARM::VST1d64T:
1734    case ARM::VST1d8T_UPD:
1735    case ARM::VST1d16T_UPD:
1736    case ARM::VST1d32T_UPD:
1737    case ARM::VST1d64T_UPD:
1738    case ARM::VST1d8Q:
1739    case ARM::VST1d16Q:
1740    case ARM::VST1d32Q:
1741    case ARM::VST1d64Q:
1742    case ARM::VST1d8Q_UPD:
1743    case ARM::VST1d16Q_UPD:
1744    case ARM::VST1d32Q_UPD:
1745    case ARM::VST1d64Q_UPD:
1746    case ARM::VST2q8:
1747    case ARM::VST2q16:
1748    case ARM::VST2q32:
1749    case ARM::VST2q8_UPD:
1750    case ARM::VST2q16_UPD:
1751    case ARM::VST2q32_UPD:
1752    case ARM::VST3d8:
1753    case ARM::VST3d16:
1754    case ARM::VST3d32:
1755    case ARM::VST3d8_UPD:
1756    case ARM::VST3d16_UPD:
1757    case ARM::VST3d32_UPD:
1758    case ARM::VST4d8:
1759    case ARM::VST4d16:
1760    case ARM::VST4d32:
1761    case ARM::VST4d8_UPD:
1762    case ARM::VST4d16_UPD:
1763    case ARM::VST4d32_UPD:
1764      if (!DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)) return false;
1765      break;
1766    case ARM::VST3q8:
1767    case ARM::VST3q16:
1768    case ARM::VST3q32:
1769    case ARM::VST3q8_UPD:
1770    case ARM::VST3q16_UPD:
1771    case ARM::VST3q32_UPD:
1772    case ARM::VST4q8:
1773    case ARM::VST4q16:
1774    case ARM::VST4q32:
1775    case ARM::VST4q8_UPD:
1776    case ARM::VST4q16_UPD:
1777    case ARM::VST4q32_UPD:
1778      if (!DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)) return false;
1779      break;
1780    default:
1781      break;
1782  }
1783
1784  // Fourth input register
1785  switch (Inst.getOpcode()) {
1786    case ARM::VST1d8Q:
1787    case ARM::VST1d16Q:
1788    case ARM::VST1d32Q:
1789    case ARM::VST1d64Q:
1790    case ARM::VST1d8Q_UPD:
1791    case ARM::VST1d16Q_UPD:
1792    case ARM::VST1d32Q_UPD:
1793    case ARM::VST1d64Q_UPD:
1794    case ARM::VST2q8:
1795    case ARM::VST2q16:
1796    case ARM::VST2q32:
1797    case ARM::VST2q8_UPD:
1798    case ARM::VST2q16_UPD:
1799    case ARM::VST2q32_UPD:
1800    case ARM::VST4d8:
1801    case ARM::VST4d16:
1802    case ARM::VST4d32:
1803    case ARM::VST4d8_UPD:
1804    case ARM::VST4d16_UPD:
1805    case ARM::VST4d32_UPD:
1806      if (!DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)) return false;
1807      break;
1808    case ARM::VST4q8:
1809    case ARM::VST4q16:
1810    case ARM::VST4q32:
1811    case ARM::VST4q8_UPD:
1812    case ARM::VST4q16_UPD:
1813    case ARM::VST4q32_UPD:
1814      if (!DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)) return false;
1815      break;
1816    default:
1817      break;
1818  }
1819
1820  return true;
1821}
1822
1823static bool DecodeVLD1DupInstruction(llvm::MCInst &Inst, unsigned Insn,
1824                                    uint64_t Address, const void *Decoder) {
1825  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1826  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1827  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1828  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1829  unsigned align = fieldFromInstruction32(Insn, 4, 1);
1830  unsigned size = fieldFromInstruction32(Insn, 6, 2);
1831  unsigned regs = fieldFromInstruction32(Insn, 5, 1) + 1;
1832
1833  align *= (1 << size);
1834
1835  if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
1836  if (regs == 2) {
1837    if (!DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)) return false;
1838  }
1839  if (Rm == 0xD) {
1840    if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1841  }
1842
1843  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1844  Inst.addOperand(MCOperand::CreateImm(align));
1845
1846  if (Rm == 0xD)
1847    Inst.addOperand(MCOperand::CreateReg(0));
1848  else if (Rm != 0xF) {
1849    if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
1850  }
1851
1852  return true;
1853}
1854
1855static bool DecodeVLD2DupInstruction(llvm::MCInst &Inst, unsigned Insn,
1856                                    uint64_t Address, const void *Decoder) {
1857  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1858  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1859  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1860  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1861  unsigned align = fieldFromInstruction32(Insn, 4, 1);
1862  unsigned size = 1 << fieldFromInstruction32(Insn, 6, 2);
1863  unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
1864  align *= 2*size;
1865
1866  if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
1867  if (!DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)) return false;
1868  if (Rm == 0xD) {
1869    if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1870  }
1871
1872  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1873  Inst.addOperand(MCOperand::CreateImm(align));
1874
1875  if (Rm == 0xD)
1876    Inst.addOperand(MCOperand::CreateReg(0));
1877  else if (Rm != 0xF) {
1878    if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
1879  }
1880
1881  return true;
1882}
1883
1884static bool DecodeVLD3DupInstruction(llvm::MCInst &Inst, unsigned Insn,
1885                                    uint64_t Address, const void *Decoder) {
1886  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1887  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1888  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1889  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1890  unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
1891
1892  if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)          ||
1893      !DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder) ||
1894      !DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder))
1895    return false;
1896  if (Rm == 0xD) {
1897    if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1898  }
1899
1900  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1901  Inst.addOperand(MCOperand::CreateImm(0));
1902
1903  if (Rm == 0xD)
1904    Inst.addOperand(MCOperand::CreateReg(0));
1905  else if (Rm != 0xF) {
1906    if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
1907  }
1908
1909  return true;
1910}
1911
1912static bool DecodeVLD4DupInstruction(llvm::MCInst &Inst, unsigned Insn,
1913                                    uint64_t Address, const void *Decoder) {
1914  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1915  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1916  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1917  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1918  unsigned size = fieldFromInstruction32(Insn, 6, 2);
1919  unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
1920  unsigned align = fieldFromInstruction32(Insn, 4, 1);
1921
1922  if (size == 0x3) {
1923    size = 4;
1924    align = 16;
1925  } else {
1926    if (size == 2) {
1927      size = 1 << size;
1928      align *= 8;
1929    } else {
1930      size = 1 << size;
1931      align *= 4*size;
1932    }
1933  }
1934
1935  if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)            ||
1936      !DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)   ||
1937      !DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder) ||
1938      !DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder))
1939    return false;
1940  if (Rm == 0xD) {
1941    if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1942  }
1943
1944  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1945  Inst.addOperand(MCOperand::CreateImm(align));
1946
1947  if (Rm == 0xD)
1948    Inst.addOperand(MCOperand::CreateReg(0));
1949  else if (Rm != 0xF) {
1950    if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
1951  }
1952
1953  return true;
1954}
1955
1956static bool DecodeNEONModImmInstruction(llvm::MCInst &Inst, unsigned Insn,
1957                                        uint64_t Address, const void *Decoder) {
1958  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1959  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1960  unsigned imm = fieldFromInstruction32(Insn, 0, 4);
1961  imm |= fieldFromInstruction32(Insn, 16, 3) << 4;
1962  imm |= fieldFromInstruction32(Insn, 24, 1) << 7;
1963  imm |= fieldFromInstruction32(Insn, 8, 4) << 8;
1964  imm |= fieldFromInstruction32(Insn, 5, 1) << 12;
1965  unsigned Q = fieldFromInstruction32(Insn, 6, 1);
1966
1967  if (Q) {
1968    if (!DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
1969  } else {
1970    if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
1971  }
1972
1973  Inst.addOperand(MCOperand::CreateImm(imm));
1974
1975  switch (Inst.getOpcode()) {
1976    case ARM::VORRiv4i16:
1977    case ARM::VORRiv2i32:
1978    case ARM::VBICiv4i16:
1979    case ARM::VBICiv2i32:
1980      if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
1981      break;
1982    case ARM::VORRiv8i16:
1983    case ARM::VORRiv4i32:
1984    case ARM::VBICiv8i16:
1985    case ARM::VBICiv4i32:
1986      if (!DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
1987      break;
1988    default:
1989      break;
1990  }
1991
1992  return true;
1993}
1994
1995static bool DecodeVSHLMaxInstruction(llvm::MCInst &Inst, unsigned Insn,
1996                                        uint64_t Address, const void *Decoder) {
1997  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1998  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1999  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2000  Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2001  unsigned size = fieldFromInstruction32(Insn, 18, 2);
2002
2003  if (!DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
2004  if (!DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
2005  Inst.addOperand(MCOperand::CreateImm(8 << size));
2006
2007  return true;
2008}
2009
2010static bool DecodeShiftRight8Imm(llvm::MCInst &Inst, unsigned Val,
2011                               uint64_t Address, const void *Decoder) {
2012  Inst.addOperand(MCOperand::CreateImm(8 - Val));
2013  return true;
2014}
2015
2016static bool DecodeShiftRight16Imm(llvm::MCInst &Inst, unsigned Val,
2017                               uint64_t Address, const void *Decoder) {
2018  Inst.addOperand(MCOperand::CreateImm(16 - Val));
2019  return true;
2020}
2021
2022static bool DecodeShiftRight32Imm(llvm::MCInst &Inst, unsigned Val,
2023                               uint64_t Address, const void *Decoder) {
2024  Inst.addOperand(MCOperand::CreateImm(32 - Val));
2025  return true;
2026}
2027
2028static bool DecodeShiftRight64Imm(llvm::MCInst &Inst, unsigned Val,
2029                               uint64_t Address, const void *Decoder) {
2030  Inst.addOperand(MCOperand::CreateImm(64 - Val));
2031  return true;
2032}
2033
2034static bool DecodeTBLInstruction(llvm::MCInst &Inst, unsigned Insn,
2035                               uint64_t Address, const void *Decoder) {
2036  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2037  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2038  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2039  Rn |= fieldFromInstruction32(Insn, 7, 1) << 4;
2040  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2041  Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2042  unsigned op = fieldFromInstruction32(Insn, 6, 1);
2043  unsigned length = fieldFromInstruction32(Insn, 8, 2) + 1;
2044
2045  if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
2046  if (op) {
2047    if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)) return false; // Writeback
2048  }
2049
2050  for (unsigned i = 0; i < length; ++i) {
2051    if (!DecodeDPRRegisterClass(Inst, (Rn+i)%32, Address, Decoder)) return false;
2052  }
2053
2054  if (!DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
2055
2056  return true;
2057}
2058
2059static bool DecodeVFPfpImm(llvm::MCInst &Inst, unsigned Val,
2060                            uint64_t Address, const void *Decoder) {
2061  // The immediate needs to be a fully instantiated float.  However, the
2062  // auto-generated decoder is only able to fill in some of the bits
2063  // necessary.  For instance, the 'b' bit is replicated multiple times,
2064  // and is even present in inverted form in one bit.  We do a little
2065  // binary parsing here to fill in those missing bits, and then
2066  // reinterpret it all as a float.
2067  union {
2068    uint32_t integer;
2069    float fp;
2070  } fp_conv;
2071
2072  fp_conv.integer = Val;
2073  uint32_t b = fieldFromInstruction32(Val, 25, 1);
2074  fp_conv.integer |= b << 26;
2075  fp_conv.integer |= b << 27;
2076  fp_conv.integer |= b << 28;
2077  fp_conv.integer |= b << 29;
2078  fp_conv.integer |= (~b & 0x1) << 30;
2079
2080  Inst.addOperand(MCOperand::CreateFPImm(fp_conv.fp));
2081  return true;
2082}
2083
2084static bool DecodeThumbAddSpecialReg(llvm::MCInst &Inst, uint16_t Insn,
2085                                     uint64_t Address, const void *Decoder) {
2086  unsigned dst = fieldFromInstruction16(Insn, 8, 3);
2087  unsigned imm = fieldFromInstruction16(Insn, 0, 8);
2088
2089  if (!DecodetGPRRegisterClass(Inst, dst, Address, Decoder)) return false;
2090
2091  if (Inst.getOpcode() == ARM::tADR)
2092    Inst.addOperand(MCOperand::CreateReg(ARM::PC));
2093  else if (Inst.getOpcode() == ARM::tADDrSPi)
2094    Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2095  else
2096    return false;
2097
2098  Inst.addOperand(MCOperand::CreateImm(imm));
2099  return true;
2100}
2101
2102static bool DecodeThumbBROperand(llvm::MCInst &Inst, unsigned Val,
2103                                 uint64_t Address, const void *Decoder) {
2104  Inst.addOperand(MCOperand::CreateImm(SignExtend32<12>(Val << 1)));
2105  return true;
2106}
2107
2108static bool DecodeT2BROperand(llvm::MCInst &Inst, unsigned Val,
2109                                 uint64_t Address, const void *Decoder) {
2110  Inst.addOperand(MCOperand::CreateImm(SignExtend32<21>(Val)));
2111  return true;
2112}
2113
2114static bool DecodeThumbCmpBROperand(llvm::MCInst &Inst, unsigned Val,
2115                                 uint64_t Address, const void *Decoder) {
2116  Inst.addOperand(MCOperand::CreateImm(SignExtend32<7>(Val << 1)));
2117  return true;
2118}
2119
2120static bool DecodeThumbAddrModeRR(llvm::MCInst &Inst, unsigned Val,
2121                                 uint64_t Address, const void *Decoder) {
2122  unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2123  unsigned Rm = fieldFromInstruction32(Val, 3, 3);
2124
2125  if (!DecodetGPRRegisterClass(Inst, Rn, Address, Decoder) ||
2126      !DecodetGPRRegisterClass(Inst, Rm, Address, Decoder))
2127    return false;
2128
2129  return true;
2130}
2131
2132static bool DecodeThumbAddrModeIS(llvm::MCInst &Inst, unsigned Val,
2133                                  uint64_t Address, const void *Decoder) {
2134  unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2135  unsigned imm = fieldFromInstruction32(Val, 3, 5);
2136
2137  if (!DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
2138  Inst.addOperand(MCOperand::CreateImm(imm));
2139
2140  return true;
2141}
2142
2143static bool DecodeThumbAddrModePC(llvm::MCInst &Inst, unsigned Val,
2144                                  uint64_t Address, const void *Decoder) {
2145  Inst.addOperand(MCOperand::CreateImm(Val << 2));
2146
2147  return true;
2148}
2149
2150static bool DecodeThumbAddrModeSP(llvm::MCInst &Inst, unsigned Val,
2151                                  uint64_t Address, const void *Decoder) {
2152  Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2153  Inst.addOperand(MCOperand::CreateImm(Val << 2));
2154
2155  return true;
2156}
2157
2158static bool DecodeT2AddrModeSOReg(llvm::MCInst &Inst, unsigned Val,
2159                                  uint64_t Address, const void *Decoder) {
2160  unsigned Rn = fieldFromInstruction32(Val, 6, 4);
2161  unsigned Rm = fieldFromInstruction32(Val, 2, 4);
2162  unsigned imm = fieldFromInstruction32(Val, 0, 2);
2163
2164  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder) ||
2165      !DecoderGPRRegisterClass(Inst, Rm, Address, Decoder))
2166    return false;
2167  Inst.addOperand(MCOperand::CreateImm(imm));
2168
2169  return true;
2170}
2171
2172static bool DecodeT2LoadShift(llvm::MCInst &Inst, unsigned Insn,
2173                              uint64_t Address, const void *Decoder) {
2174  if (Inst.getOpcode() != ARM::t2PLDs) {
2175    unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2176    if (!DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)) return false;
2177  }
2178
2179  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2180  if (Rn == 0xF) {
2181    switch (Inst.getOpcode()) {
2182      case ARM::t2LDRBs:
2183        Inst.setOpcode(ARM::t2LDRBpci);
2184        break;
2185      case ARM::t2LDRHs:
2186        Inst.setOpcode(ARM::t2LDRHpci);
2187        break;
2188      case ARM::t2LDRSHs:
2189        Inst.setOpcode(ARM::t2LDRSHpci);
2190        break;
2191      case ARM::t2LDRSBs:
2192        Inst.setOpcode(ARM::t2LDRSBpci);
2193        break;
2194      case ARM::t2PLDs:
2195        Inst.setOpcode(ARM::t2PLDi12);
2196        Inst.addOperand(MCOperand::CreateReg(ARM::PC));
2197        break;
2198      default:
2199        return false;
2200    }
2201
2202    int imm = fieldFromInstruction32(Insn, 0, 12);
2203    if (!fieldFromInstruction32(Insn, 23, 1)) imm *= -1;
2204    Inst.addOperand(MCOperand::CreateImm(imm));
2205
2206    return true;
2207  }
2208
2209  unsigned addrmode = fieldFromInstruction32(Insn, 4, 2);
2210  addrmode |= fieldFromInstruction32(Insn, 0, 4) << 2;
2211  addrmode |= fieldFromInstruction32(Insn, 16, 4) << 6;
2212  DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder);
2213
2214  return true;
2215}
2216
2217static bool DecodeT2Imm8S4(llvm::MCInst &Inst, unsigned Val,
2218                           uint64_t Address, const void *Decoder) {
2219  int imm = Val & 0xFF;
2220  if (!(Val & 0x100)) imm *= -1;
2221  Inst.addOperand(MCOperand::CreateImm(imm << 2));
2222
2223  return true;
2224}
2225
2226static bool DecodeT2AddrModeImm8s4(llvm::MCInst &Inst, unsigned Val,
2227                                   uint64_t Address, const void *Decoder) {
2228  unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2229  unsigned imm = fieldFromInstruction32(Val, 0, 9);
2230
2231  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder) ||
2232      !DecodeT2Imm8S4(Inst, imm, Address, Decoder))
2233    return false;
2234
2235  return true;
2236}
2237
2238static bool DecodeT2Imm8(llvm::MCInst &Inst, unsigned Val,
2239                         uint64_t Address, const void *Decoder) {
2240  int imm = Val & 0xFF;
2241  if (!(Val & 0x100)) imm *= -1;
2242  Inst.addOperand(MCOperand::CreateImm(imm));
2243
2244  return true;
2245}
2246
2247
2248static bool DecodeT2AddrModeImm8(llvm::MCInst &Inst, unsigned Val,
2249                                 uint64_t Address, const void *Decoder) {
2250  unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2251  unsigned imm = fieldFromInstruction32(Val, 0, 9);
2252
2253  // Some instructions always use an additive offset.
2254  switch (Inst.getOpcode()) {
2255    case ARM::t2LDRT:
2256    case ARM::t2LDRBT:
2257    case ARM::t2LDRHT:
2258    case ARM::t2LDRSBT:
2259    case ARM::t2LDRSHT:
2260      imm |= 0x100;
2261      break;
2262    default:
2263      break;
2264  }
2265
2266  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder) ||
2267      !DecodeT2Imm8(Inst, imm, Address, Decoder))
2268    return false;
2269
2270  return true;
2271}
2272
2273
2274static bool DecodeT2AddrModeImm12(llvm::MCInst &Inst, unsigned Val,
2275                                  uint64_t Address, const void *Decoder) {
2276  unsigned Rn = fieldFromInstruction32(Val, 13, 4);
2277  unsigned imm = fieldFromInstruction32(Val, 0, 12);
2278
2279  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
2280  Inst.addOperand(MCOperand::CreateImm(imm));
2281
2282  return true;
2283}
2284
2285
2286static bool DecodeThumbAddSPImm(llvm::MCInst &Inst, uint16_t Insn,
2287                                uint64_t Address, const void *Decoder) {
2288  unsigned imm = fieldFromInstruction16(Insn, 0, 7);
2289
2290  Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2291  Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2292  Inst.addOperand(MCOperand::CreateImm(imm));
2293
2294  return true;
2295}
2296
2297static bool DecodeThumbAddSPReg(llvm::MCInst &Inst, uint16_t Insn,
2298                                uint64_t Address, const void *Decoder) {
2299  if (Inst.getOpcode() == ARM::tADDrSP) {
2300    unsigned Rdm = fieldFromInstruction16(Insn, 0, 3);
2301    Rdm |= fieldFromInstruction16(Insn, 7, 1) << 3;
2302
2303    if (!DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)) return false;
2304    Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2305    if (!DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)) return false;
2306  } else if (Inst.getOpcode() == ARM::tADDspr) {
2307    unsigned Rm = fieldFromInstruction16(Insn, 3, 4);
2308
2309    Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2310    Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2311    if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
2312  }
2313
2314  return true;
2315}
2316
2317static bool DecodeThumbCPS(llvm::MCInst &Inst, uint16_t Insn,
2318                           uint64_t Address, const void *Decoder) {
2319  unsigned imod = fieldFromInstruction16(Insn, 4, 1) | 0x2;
2320  unsigned flags = fieldFromInstruction16(Insn, 0, 3);
2321
2322  Inst.addOperand(MCOperand::CreateImm(imod));
2323  Inst.addOperand(MCOperand::CreateImm(flags));
2324
2325  return true;
2326}
2327
2328static bool DecodePostIdxReg(llvm::MCInst &Inst, unsigned Insn,
2329                             uint64_t Address, const void *Decoder) {
2330  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2331  unsigned add = fieldFromInstruction32(Insn, 4, 1);
2332
2333  if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
2334  Inst.addOperand(MCOperand::CreateImm(add));
2335
2336  return true;
2337}
2338
2339static bool DecodeThumbBLXOffset(llvm::MCInst &Inst, unsigned Val,
2340                                 uint64_t Address, const void *Decoder) {
2341  Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
2342  return true;
2343}
2344
2345static bool DecodeCoprocessor(llvm::MCInst &Inst, unsigned Val,
2346                              uint64_t Address, const void *Decoder) {
2347  if (Val == 0xA || Val == 0xB)
2348    return false;
2349
2350  Inst.addOperand(MCOperand::CreateImm(Val));
2351  return true;
2352}
2353
2354static bool DecodeThumbSRImm(llvm::MCInst &Inst, unsigned Val,
2355                             uint64_t Address, const void *Decoder) {
2356  if (Val == 0)
2357    Inst.addOperand(MCOperand::CreateImm(32));
2358  else
2359    Inst.addOperand(MCOperand::CreateImm(Val));
2360  return true;
2361}
2362
2363static bool DecodeThumb2BCCInstruction(llvm::MCInst &Inst, unsigned Insn,
2364                                       uint64_t Address, const void *Decoder) {
2365  unsigned pred = fieldFromInstruction32(Insn, 22, 4);
2366  if (pred == 0xE || pred == 0xF) {
2367    unsigned opc = fieldFromInstruction32(Insn, 4, 2);
2368    switch (opc) {
2369      default:
2370        return false;
2371      case 0:
2372        Inst.setOpcode(ARM::t2DSB);
2373        break;
2374      case 1:
2375        Inst.setOpcode(ARM::t2DMB);
2376        break;
2377      case 2:
2378        Inst.setOpcode(ARM::t2ISB);
2379        return true;
2380    }
2381
2382    unsigned imm = fieldFromInstruction32(Insn, 0, 4);
2383    return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
2384  }
2385
2386  unsigned brtarget = fieldFromInstruction32(Insn, 0, 11) << 1;
2387  brtarget |= fieldFromInstruction32(Insn, 11, 1) << 19;
2388  brtarget |= fieldFromInstruction32(Insn, 13, 1) << 18;
2389  brtarget |= fieldFromInstruction32(Insn, 16, 6) << 12;
2390  brtarget |= fieldFromInstruction32(Insn, 26, 1) << 20;
2391
2392  if (!DecodeT2BROperand(Inst, brtarget, Address, Decoder) ||
2393      !DecodePredicateOperand(Inst, pred, Address, Decoder))
2394    return false;
2395
2396  return true;
2397}
2398
2399// Decode a shifted immediate operand.  These basically consist
2400// of an 8-bit value, and a 4-bit directive that specifies either
2401// a splat operation or a rotation.
2402static bool DecodeT2SOImm(llvm::MCInst &Inst, unsigned Val,
2403                          uint64_t Address, const void *Decoder) {
2404  unsigned ctrl = fieldFromInstruction32(Val, 10, 2);
2405  if (ctrl == 0) {
2406    unsigned byte = fieldFromInstruction32(Val, 8, 2);
2407    unsigned imm = fieldFromInstruction32(Val, 0, 8);
2408    switch (byte) {
2409      case 0:
2410        Inst.addOperand(MCOperand::CreateImm(imm));
2411        break;
2412      case 1:
2413        Inst.addOperand(MCOperand::CreateImm((imm << 16) | imm));
2414        break;
2415      case 2:
2416        Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 8)));
2417        break;
2418      case 3:
2419        Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 16) |
2420                                             (imm << 8)  |  imm));
2421        break;
2422    }
2423  } else {
2424    unsigned unrot = fieldFromInstruction32(Val, 0, 7) | 0x80;
2425    unsigned rot = fieldFromInstruction32(Val, 7, 5);
2426    unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
2427    Inst.addOperand(MCOperand::CreateImm(imm));
2428  }
2429
2430  return true;
2431}
2432
2433static bool DecodeThumbBCCTargetOperand(llvm::MCInst &Inst, unsigned Val,
2434                                        uint64_t Address, const void *Decoder){
2435  Inst.addOperand(MCOperand::CreateImm(Val << 1));
2436  return true;
2437}
2438
2439static bool DecodeThumbBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
2440                                       uint64_t Address, const void *Decoder){
2441  Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
2442  return true;
2443}
2444
2445static bool DecodeAddrMode3Offset(llvm::MCInst &Inst, unsigned Val,
2446                                  uint64_t Address, const void *Decoder) {
2447  bool isImm = fieldFromInstruction32(Val, 9, 1);
2448  bool isAdd = fieldFromInstruction32(Val, 8, 1);
2449  unsigned imm = fieldFromInstruction32(Val, 0, 8);
2450
2451  if (!isImm) {
2452    if (!DecodeGPRRegisterClass(Inst, imm, Address, Decoder)) return false;
2453    Inst.addOperand(MCOperand::CreateImm(!isAdd << 8));
2454  } else {
2455    Inst.addOperand(MCOperand::CreateReg(0));
2456    Inst.addOperand(MCOperand::CreateImm(imm | (!isAdd << 8)));
2457  }
2458
2459  return true;
2460}
2461
2462static bool DecodeMemBarrierOption(llvm::MCInst &Inst, unsigned Val,
2463                                   uint64_t Address, const void *Decoder) {
2464  switch (Val) {
2465  default:
2466    return false;
2467  case 0xF: // SY
2468  case 0xE: // ST
2469  case 0xB: // ISH
2470  case 0xA: // ISHST
2471  case 0x7: // NSH
2472  case 0x6: // NSHST
2473  case 0x3: // OSH
2474  case 0x2: // OSHST
2475    break;
2476  }
2477
2478  Inst.addOperand(MCOperand::CreateImm(Val));
2479  return true;
2480}
2481
2482static bool DecodeMSRMask(llvm::MCInst &Inst, unsigned Val,
2483                          uint64_t Address, const void *Decoder) {
2484  if (!Val) return false;
2485  Inst.addOperand(MCOperand::CreateImm(Val));
2486  return true;
2487}
2488
2489static bool DecodeDoubleRegExclusive(llvm::MCInst &Inst, unsigned Insn,
2490                                          uint64_t Address, const void *Decoder) {
2491  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2492  unsigned Rt = fieldFromInstruction32(Insn, 0, 4);
2493  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2494
2495  if (Inst.getOpcode() == ARM::STREXD)
2496    if (!DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
2497
2498  if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return false;
2499  if (Rd == Rn || Rd == Rt || Rd == Rt+1) return false;
2500
2501  if (!DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)) return false;
2502  if (!DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)) return false;
2503  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
2504
2505  return true;
2506}
2507
2508
2509