ARMDisassembler.cpp revision 0d09499cf3e2d927cdc53ec79895303ac12808ac
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 DecodeMemBarrierOption(llvm::MCInst &Inst, unsigned Insn,
133                               uint64_t Address, const void *Decoder);
134static bool DecodeMSRMask(llvm::MCInst &Inst, unsigned Insn,
135                               uint64_t Address, const void *Decoder);
136static bool DecodeDoubleRegLoad(llvm::MCInst &Inst, unsigned Insn,
137                               uint64_t Address, const void *Decoder);
138static bool DecodeDoubleRegStore(llvm::MCInst &Inst, unsigned Insn,
139                               uint64_t Address, const void *Decoder);
140static bool DecodeSTRPreImm(llvm::MCInst &Inst, unsigned Insn,
141                               uint64_t Address, const void *Decoder);
142static bool DecodeSTRPreReg(llvm::MCInst &Inst, unsigned Insn,
143                               uint64_t Address, const void *Decoder);
144
145
146static bool DecodeThumbAddSpecialReg(llvm::MCInst &Inst, uint16_t Insn,
147                               uint64_t Address, const void *Decoder);
148static bool DecodeThumbBROperand(llvm::MCInst &Inst, unsigned Val,
149                               uint64_t Address, const void *Decoder);
150static bool DecodeT2BROperand(llvm::MCInst &Inst, unsigned Val,
151                               uint64_t Address, const void *Decoder);
152static bool DecodeThumbCmpBROperand(llvm::MCInst &Inst, unsigned Val,
153                               uint64_t Address, const void *Decoder);
154static bool DecodeThumbAddrModeRR(llvm::MCInst &Inst, unsigned Val,
155                               uint64_t Address, const void *Decoder);
156static bool DecodeThumbAddrModeIS(llvm::MCInst &Inst, unsigned Val,
157                               uint64_t Address, const void *Decoder);
158static bool DecodeThumbAddrModePC(llvm::MCInst &Inst, unsigned Val,
159                               uint64_t Address, const void *Decoder);
160static bool DecodeThumbAddrModeSP(llvm::MCInst &Inst, unsigned Val,
161                               uint64_t Address, const void *Decoder);
162static bool DecodeT2AddrModeSOReg(llvm::MCInst &Inst, unsigned Val,
163                               uint64_t Address, const void *Decoder);
164static bool DecodeT2LoadShift(llvm::MCInst &Inst, unsigned Val,
165                               uint64_t Address, const void *Decoder);
166static bool DecodeT2Imm8S4(llvm::MCInst &Inst, unsigned Val,
167                               uint64_t Address, const void *Decoder);
168static bool DecodeT2AddrModeImm8s4(llvm::MCInst &Inst, unsigned Val,
169                               uint64_t Address, const void *Decoder);
170static bool DecodeT2Imm8(llvm::MCInst &Inst, unsigned Val,
171                               uint64_t Address, const void *Decoder);
172static bool DecodeT2AddrModeImm8(llvm::MCInst &Inst, unsigned Val,
173                               uint64_t Address, const void *Decoder);
174static bool DecodeThumbAddSPImm(llvm::MCInst &Inst, uint16_t Val,
175                               uint64_t Address, const void *Decoder);
176static bool DecodeThumbAddSPReg(llvm::MCInst &Inst, uint16_t Insn,
177                                uint64_t Address, const void *Decoder);
178static bool DecodeThumbCPS(llvm::MCInst &Inst, uint16_t Insn,
179                                uint64_t Address, const void *Decoder);
180static bool DecodeThumbBLXOffset(llvm::MCInst &Inst, unsigned Insn,
181                                uint64_t Address, const void *Decoder);
182static bool DecodeT2AddrModeImm12(llvm::MCInst &Inst, unsigned Val,
183                                uint64_t Address, const void *Decoder);
184static bool DecodeThumbSRImm(llvm::MCInst &Inst, unsigned Val,
185                                uint64_t Address, const void *Decoder);
186static bool DecodeThumb2BCCInstruction(llvm::MCInst &Inst, unsigned Val,
187                                uint64_t Address, const void *Decoder);
188static bool DecodeT2SOImm(llvm::MCInst &Inst, unsigned Val,
189                                uint64_t Address, const void *Decoder);
190static bool DecodeThumbBCCTargetOperand(llvm::MCInst &Inst, unsigned Val,
191                                uint64_t Address, const void *Decoder);
192static bool DecodeThumbBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
193                                uint64_t Address, const void *Decoder);
194
195#include "ARMGenDisassemblerTables.inc"
196#include "ARMGenInstrInfo.inc"
197#include "ARMGenEDInfo.inc"
198
199using namespace llvm;
200
201static MCDisassembler *createARMDisassembler(const Target &T) {
202  return new ARMDisassembler;
203}
204
205static MCDisassembler *createThumbDisassembler(const Target &T) {
206  return new ThumbDisassembler;
207}
208
209EDInstInfo *ARMDisassembler::getEDInfo() const {
210  return instInfoARM;
211}
212
213EDInstInfo *ThumbDisassembler::getEDInfo() const {
214  return instInfoARM;
215}
216
217
218bool ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
219                                     const MemoryObject &Region,
220                                     uint64_t Address,raw_ostream &os) const {
221  uint8_t bytes[4];
222
223  // We want to read exactly 4 bytes of data.
224  if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1)
225    return false;
226
227  // Encoded as a small-endian 32-bit word in the stream.
228  uint32_t insn = (bytes[3] << 24) |
229                  (bytes[2] << 16) |
230                  (bytes[1] <<  8) |
231                  (bytes[0] <<  0);
232
233  // Calling the auto-generated decoder function.
234  bool result = decodeARMInstruction32(MI, insn, Address, this);
235  if (result) {
236    Size = 4;
237    return true;
238  }
239
240  // Instructions that are shared between ARM and Thumb modes.
241  // FIXME: This shouldn't really exist.  It's an artifact of the
242  // fact that we fail to encode a few instructions properly for Thumb.
243  MI.clear();
244  result = decodeCommonInstruction32(MI, insn, Address, this);
245  if (result) {
246    Size = 4;
247    return true;
248  }
249
250  // VFP and NEON instructions, similarly, are shared between ARM
251  // and Thumb modes.
252  MI.clear();
253  result = decodeVFPInstruction32(MI, insn, Address, this);
254  if (result) {
255    Size = 4;
256    return true;
257  }
258
259  MI.clear();
260  result = decodeNEONDataInstruction32(MI, insn, Address, this);
261  if (result) {
262    Size = 4;
263    // Add a fake predicate operand, because we share these instruction
264    // definitions with Thumb2 where these instructions are predicable.
265    if (!DecodePredicateOperand(MI, 0xE, Address, this)) return false;
266    return true;
267  }
268
269  MI.clear();
270  result = decodeNEONLoadStoreInstruction32(MI, insn, Address, this);
271  if (result) {
272    Size = 4;
273    // Add a fake predicate operand, because we share these instruction
274    // definitions with Thumb2 where these instructions are predicable.
275    if (!DecodePredicateOperand(MI, 0xE, Address, this)) return false;
276    return true;
277  }
278
279  MI.clear();
280  result = decodeNEONDupInstruction32(MI, insn, Address, this);
281  if (result) {
282    Size = 4;
283    // Add a fake predicate operand, because we share these instruction
284    // definitions with Thumb2 where these instructions are predicable.
285    if (!DecodePredicateOperand(MI, 0xE, Address, this)) return false;
286    return true;
287  }
288
289  MI.clear();
290
291  return false;
292}
293
294namespace llvm {
295extern MCInstrDesc ARMInsts[];
296}
297
298// Thumb1 instructions don't have explicit S bits.  Rather, they
299// implicitly set CPSR.  Since it's not represented in the encoding, the
300// auto-generated decoder won't inject the CPSR operand.  We need to fix
301// that as a post-pass.
302static void AddThumb1SBit(MCInst &MI, bool InITBlock) {
303  const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
304  MCInst::iterator I = MI.begin();
305  for (unsigned i = 0, e = MI.size(); i < e; ++i, ++I) {
306    if (OpInfo[i].isOptionalDef() && OpInfo[i].RegClass == ARM::CCRRegClassID) {
307      MI.insert(I, MCOperand::CreateReg(InITBlock ? 0 : ARM::CPSR));
308      return;
309    }
310  }
311
312  if (OpInfo[MI.size()].isOptionalDef() &&
313      OpInfo[MI.size()].RegClass == ARM::CCRRegClassID)
314    MI.insert(MI.end(), MCOperand::CreateReg(InITBlock ? 0 : ARM::CPSR));
315}
316
317// Most Thumb instructions don't have explicit predicates in the
318// encoding, but rather get their predicates from IT context.  We need
319// to fix up the predicate operands using this context information as a
320// post-pass.
321void ThumbDisassembler::AddThumbPredicate(MCInst &MI) const {
322  // A few instructions actually have predicates encoded in them.  Don't
323  // try to overwrite it if we're seeing one of those.
324  switch (MI.getOpcode()) {
325    case ARM::tBcc:
326    case ARM::t2Bcc:
327      return;
328    default:
329      break;
330  }
331
332  // If we're in an IT block, base the predicate on that.  Otherwise,
333  // assume a predicate of AL.
334  unsigned CC;
335  if (!ITBlock.empty()) {
336    CC = ITBlock.back();
337    ITBlock.pop_back();
338  } else
339    CC = ARMCC::AL;
340
341  const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
342  MCInst::iterator I = MI.begin();
343  for (unsigned i = 0, e = MI.size(); i < e; ++i, ++I) {
344    if (OpInfo[i].isPredicate()) {
345      I = MI.insert(I, MCOperand::CreateImm(CC));
346      ++I;
347      if (CC == ARMCC::AL)
348        MI.insert(I, MCOperand::CreateReg(0));
349      else
350        MI.insert(I, MCOperand::CreateReg(ARM::CPSR));
351      return;
352    }
353  }
354
355  MI.insert(MI.end(), MCOperand::CreateImm(CC));
356  if (CC == ARMCC::AL)
357    MI.insert(MI.end(), MCOperand::CreateReg(0));
358  else
359    MI.insert(MI.end(), MCOperand::CreateReg(ARM::CPSR));
360}
361
362// Thumb VFP instructions are a special case.  Because we share their
363// encodings between ARM and Thumb modes, and they are predicable in ARM
364// mode, the auto-generated decoder will give them an (incorrect)
365// predicate operand.  We need to rewrite these operands based on the IT
366// context as a post-pass.
367void ThumbDisassembler::UpdateThumbVFPPredicate(MCInst &MI) const {
368  unsigned CC;
369  if (!ITBlock.empty()) {
370    CC = ITBlock.back();
371    ITBlock.pop_back();
372  } else
373    CC = ARMCC::AL;
374
375  const MCOperandInfo *OpInfo = ARMInsts[MI.getOpcode()].OpInfo;
376  MCInst::iterator I = MI.begin();
377  for (unsigned i = 0, e = MI.size(); i < e; ++i, ++I) {
378    if (OpInfo[i].isPredicate() ) {
379      I->setImm(CC);
380      ++I;
381      if (CC == ARMCC::AL)
382        I->setReg(0);
383      else
384        I->setReg(ARM::CPSR);
385      return;
386    }
387  }
388}
389
390
391bool ThumbDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
392                                       const MemoryObject &Region,
393                                       uint64_t Address,raw_ostream &os) const {
394  uint8_t bytes[4];
395
396  // We want to read exactly 2 bytes of data.
397  if (Region.readBytes(Address, 2, (uint8_t*)bytes, NULL) == -1)
398    return false;
399
400  uint16_t insn16 = (bytes[1] << 8) | bytes[0];
401  bool result = decodeThumbInstruction16(MI, insn16, Address, this);
402  if (result) {
403    Size = 2;
404    bool InITBlock = !ITBlock.empty();
405    AddThumbPredicate(MI);
406    AddThumb1SBit(MI, InITBlock);
407    return true;
408  }
409
410  MI.clear();
411  result = decodeThumb2Instruction16(MI, insn16, Address, this);
412  if (result) {
413    Size = 2;
414    AddThumbPredicate(MI);
415
416    // If we find an IT instruction, we need to parse its condition
417    // code and mask operands so that we can apply them correctly
418    // to the subsequent instructions.
419    if (MI.getOpcode() == ARM::t2IT) {
420      unsigned firstcond = MI.getOperand(0).getImm();
421      uint32_t mask = MI.getOperand(1).getImm();
422      unsigned zeros = CountTrailingZeros_32(mask);
423      mask >>= zeros+1;
424
425      for (unsigned i = 0; i < 4 - (zeros+1); ++i) {
426        if (firstcond ^ (mask & 1))
427          ITBlock.push_back(firstcond ^ 1);
428        else
429          ITBlock.push_back(firstcond);
430        mask >>= 1;
431      }
432      ITBlock.push_back(firstcond);
433    }
434
435    return true;
436  }
437
438  // We want to read exactly 4 bytes of data.
439  if (Region.readBytes(Address, 4, (uint8_t*)bytes, NULL) == -1)
440    return false;
441
442  uint32_t insn32 = (bytes[3] <<  8) |
443                    (bytes[2] <<  0) |
444                    (bytes[1] << 24) |
445                    (bytes[0] << 16);
446  MI.clear();
447  result = decodeThumbInstruction32(MI, insn32, Address, this);
448  if (result) {
449    Size = 4;
450    bool InITBlock = ITBlock.size();
451    AddThumbPredicate(MI);
452    AddThumb1SBit(MI, InITBlock);
453    return true;
454  }
455
456  MI.clear();
457  result = decodeThumb2Instruction32(MI, insn32, Address, this);
458  if (result) {
459    Size = 4;
460    AddThumbPredicate(MI);
461    return true;
462  }
463
464  MI.clear();
465  result = decodeCommonInstruction32(MI, insn32, Address, this);
466  if (result) {
467    Size = 4;
468    AddThumbPredicate(MI);
469    return true;
470  }
471
472  MI.clear();
473  result = decodeVFPInstruction32(MI, insn32, Address, this);
474  if (result) {
475    Size = 4;
476    UpdateThumbVFPPredicate(MI);
477    return true;
478  }
479
480  MI.clear();
481  if (fieldFromInstruction32(insn32, 24, 4) == 0xF) {
482    uint32_t NEONDataInsn = insn32;
483    NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
484    NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
485    NEONDataInsn |= 0x12000000; // Set bits 28 and 25
486    result = decodeNEONDataInstruction32(MI, NEONDataInsn, Address, this);
487    if (result) {
488      Size = 4;
489      AddThumbPredicate(MI);
490      return true;
491    }
492  }
493
494  MI.clear();
495  result = decodeNEONLoadStoreInstruction32(MI, insn32, Address, this);
496  if (result) {
497    Size = 4;
498    AddThumbPredicate(MI);
499    return true;
500  }
501
502  MI.clear();
503  result = decodeNEONDupInstruction32(MI, insn32, Address, this);
504  if (result) {
505    Size = 4;
506    AddThumbPredicate(MI);
507    return true;
508  }
509
510  return false;
511}
512
513
514extern "C" void LLVMInitializeARMDisassembler() {
515  TargetRegistry::RegisterMCDisassembler(TheARMTarget,
516                                         createARMDisassembler);
517  TargetRegistry::RegisterMCDisassembler(TheThumbTarget,
518                                         createThumbDisassembler);
519}
520
521static const unsigned GPRDecoderTable[] = {
522  ARM::R0, ARM::R1, ARM::R2, ARM::R3,
523  ARM::R4, ARM::R5, ARM::R6, ARM::R7,
524  ARM::R8, ARM::R9, ARM::R10, ARM::R11,
525  ARM::R12, ARM::SP, ARM::LR, ARM::PC
526};
527
528static bool DecodeGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
529                                   uint64_t Address, const void *Decoder) {
530  if (RegNo > 15)
531    return false;
532
533  unsigned Register = GPRDecoderTable[RegNo];
534  Inst.addOperand(MCOperand::CreateReg(Register));
535  return true;
536}
537
538static bool DecodeGPRnopcRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
539                                       uint64_t Address, const void *Decoder) {
540  if (RegNo == 15) return false;
541  return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
542}
543
544static bool DecodetGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
545                                   uint64_t Address, const void *Decoder) {
546  if (RegNo > 7)
547    return false;
548  return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
549}
550
551static bool DecodetcGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
552                                   uint64_t Address, const void *Decoder) {
553  unsigned Register = 0;
554  switch (RegNo) {
555    case 0:
556      Register = ARM::R0;
557      break;
558    case 1:
559      Register = ARM::R1;
560      break;
561    case 2:
562      Register = ARM::R2;
563      break;
564    case 3:
565      Register = ARM::R3;
566      break;
567    case 9:
568      Register = ARM::R9;
569      break;
570    case 12:
571      Register = ARM::R12;
572      break;
573    default:
574      return false;
575    }
576
577  Inst.addOperand(MCOperand::CreateReg(Register));
578  return true;
579}
580
581static bool DecoderGPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
582                                   uint64_t Address, const void *Decoder) {
583  if (RegNo == 13 || RegNo == 15) return false;
584  return DecodeGPRRegisterClass(Inst, RegNo, Address, Decoder);
585}
586
587static const unsigned SPRDecoderTable[] = {
588     ARM::S0,  ARM::S1,  ARM::S2,  ARM::S3,
589     ARM::S4,  ARM::S5,  ARM::S6,  ARM::S7,
590     ARM::S8,  ARM::S9, ARM::S10, ARM::S11,
591    ARM::S12, ARM::S13, ARM::S14, ARM::S15,
592    ARM::S16, ARM::S17, ARM::S18, ARM::S19,
593    ARM::S20, ARM::S21, ARM::S22, ARM::S23,
594    ARM::S24, ARM::S25, ARM::S26, ARM::S27,
595    ARM::S28, ARM::S29, ARM::S30, ARM::S31
596};
597
598static bool DecodeSPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
599                                   uint64_t Address, const void *Decoder) {
600  if (RegNo > 31)
601    return false;
602
603  unsigned Register = SPRDecoderTable[RegNo];
604  Inst.addOperand(MCOperand::CreateReg(Register));
605  return true;
606}
607
608static const unsigned DPRDecoderTable[] = {
609     ARM::D0,  ARM::D1,  ARM::D2,  ARM::D3,
610     ARM::D4,  ARM::D5,  ARM::D6,  ARM::D7,
611     ARM::D8,  ARM::D9, ARM::D10, ARM::D11,
612    ARM::D12, ARM::D13, ARM::D14, ARM::D15,
613    ARM::D16, ARM::D17, ARM::D18, ARM::D19,
614    ARM::D20, ARM::D21, ARM::D22, ARM::D23,
615    ARM::D24, ARM::D25, ARM::D26, ARM::D27,
616    ARM::D28, ARM::D29, ARM::D30, ARM::D31
617};
618
619static bool DecodeDPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
620                                   uint64_t Address, const void *Decoder) {
621  if (RegNo > 31)
622    return false;
623
624  unsigned Register = DPRDecoderTable[RegNo];
625  Inst.addOperand(MCOperand::CreateReg(Register));
626  return true;
627}
628
629static bool DecodeDPR_8RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
630                                   uint64_t Address, const void *Decoder) {
631  if (RegNo > 7)
632    return false;
633  return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
634}
635
636static bool DecodeDPR_VFP2RegisterClass(llvm::MCInst &Inst, unsigned RegNo,
637                                   uint64_t Address, const void *Decoder) {
638  if (RegNo > 15)
639    return false;
640  return DecodeDPRRegisterClass(Inst, RegNo, Address, Decoder);
641}
642
643static const unsigned QPRDecoderTable[] = {
644     ARM::Q0,  ARM::Q1,  ARM::Q2,  ARM::Q3,
645     ARM::Q4,  ARM::Q5,  ARM::Q6,  ARM::Q7,
646     ARM::Q8,  ARM::Q9, ARM::Q10, ARM::Q11,
647    ARM::Q12, ARM::Q13, ARM::Q14, ARM::Q15
648};
649
650
651static bool DecodeQPRRegisterClass(llvm::MCInst &Inst, unsigned RegNo,
652                                   uint64_t Address, const void *Decoder) {
653  if (RegNo > 31)
654    return false;
655  RegNo >>= 1;
656
657  unsigned Register = QPRDecoderTable[RegNo];
658  Inst.addOperand(MCOperand::CreateReg(Register));
659  return true;
660}
661
662static bool DecodePredicateOperand(llvm::MCInst &Inst, unsigned Val,
663                               uint64_t Address, const void *Decoder) {
664  if (Val == 0xF) return false;
665  // AL predicate is not allowed on Thumb1 branches.
666  if (Inst.getOpcode() == ARM::tBcc && Val == 0xE)
667    return false;
668  Inst.addOperand(MCOperand::CreateImm(Val));
669  if (Val == ARMCC::AL) {
670    Inst.addOperand(MCOperand::CreateReg(0));
671  } else
672    Inst.addOperand(MCOperand::CreateReg(ARM::CPSR));
673  return true;
674}
675
676static bool DecodeCCOutOperand(llvm::MCInst &Inst, unsigned Val,
677                               uint64_t Address, const void *Decoder) {
678  if (Val)
679    Inst.addOperand(MCOperand::CreateReg(ARM::CPSR));
680  else
681    Inst.addOperand(MCOperand::CreateReg(0));
682  return true;
683}
684
685static bool DecodeSOImmOperand(llvm::MCInst &Inst, unsigned Val,
686                               uint64_t Address, const void *Decoder) {
687  uint32_t imm = Val & 0xFF;
688  uint32_t rot = (Val & 0xF00) >> 7;
689  uint32_t rot_imm = (imm >> rot) | (imm << (32-rot));
690  Inst.addOperand(MCOperand::CreateImm(rot_imm));
691  return true;
692}
693
694static bool DecodeBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
695                               uint64_t Address, const void *Decoder) {
696  Val <<= 2;
697  Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(Val)));
698  return true;
699}
700
701static bool DecodeSORegImmOperand(llvm::MCInst &Inst, unsigned Val,
702                               uint64_t Address, const void *Decoder) {
703
704  unsigned Rm = fieldFromInstruction32(Val, 0, 4);
705  unsigned type = fieldFromInstruction32(Val, 5, 2);
706  unsigned imm = fieldFromInstruction32(Val, 7, 5);
707
708  // Register-immediate
709  if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
710
711  ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
712  switch (type) {
713    case 0:
714      Shift = ARM_AM::lsl;
715      break;
716    case 1:
717      Shift = ARM_AM::lsr;
718      break;
719    case 2:
720      Shift = ARM_AM::asr;
721      break;
722    case 3:
723      Shift = ARM_AM::ror;
724      break;
725  }
726
727  if (Shift == ARM_AM::ror && imm == 0)
728    Shift = ARM_AM::rrx;
729
730  unsigned Op = Shift | (imm << 3);
731  Inst.addOperand(MCOperand::CreateImm(Op));
732
733  return true;
734}
735
736static bool DecodeSORegRegOperand(llvm::MCInst &Inst, unsigned Val,
737                               uint64_t Address, const void *Decoder) {
738
739  unsigned Rm = fieldFromInstruction32(Val, 0, 4);
740  unsigned type = fieldFromInstruction32(Val, 5, 2);
741  unsigned Rs = fieldFromInstruction32(Val, 8, 4);
742
743  // Register-register
744  if (!DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)) return false;
745  if (!DecodeGPRnopcRegisterClass(Inst, Rs, Address, Decoder)) return false;
746
747  ARM_AM::ShiftOpc Shift = ARM_AM::lsl;
748  switch (type) {
749    case 0:
750      Shift = ARM_AM::lsl;
751      break;
752    case 1:
753      Shift = ARM_AM::lsr;
754      break;
755    case 2:
756      Shift = ARM_AM::asr;
757      break;
758    case 3:
759      Shift = ARM_AM::ror;
760      break;
761  }
762
763  Inst.addOperand(MCOperand::CreateImm(Shift));
764
765  return true;
766}
767
768static bool DecodeRegListOperand(llvm::MCInst &Inst, unsigned Val,
769                                 uint64_t Address, const void *Decoder) {
770  // Empty register lists are not allowed.
771  if (CountPopulation_32(Val) == 0) return false;
772  for (unsigned i = 0; i < 16; ++i) {
773    if (Val & (1 << i)) {
774      if (!DecodeGPRRegisterClass(Inst, i, Address, Decoder)) return false;
775    }
776  }
777
778  return true;
779}
780
781static bool DecodeSPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
782                                 uint64_t Address, const void *Decoder) {
783  unsigned Vd = fieldFromInstruction32(Val, 8, 4);
784  unsigned regs = Val & 0xFF;
785
786  if (!DecodeSPRRegisterClass(Inst, Vd, Address, Decoder)) return false;
787  for (unsigned i = 0; i < (regs - 1); ++i) {
788    if (!DecodeSPRRegisterClass(Inst, ++Vd, Address, Decoder)) return false;
789  }
790
791  return true;
792}
793
794static bool DecodeDPRRegListOperand(llvm::MCInst &Inst, unsigned Val,
795                                 uint64_t Address, const void *Decoder) {
796  unsigned Vd = fieldFromInstruction32(Val, 8, 4);
797  unsigned regs = (Val & 0xFF) / 2;
798
799  if (!DecodeDPRRegisterClass(Inst, Vd, Address, Decoder)) return false;
800  for (unsigned i = 0; i < (regs - 1); ++i) {
801    if (!DecodeDPRRegisterClass(Inst, ++Vd, Address, Decoder)) return false;
802  }
803
804  return true;
805}
806
807static bool DecodeBitfieldMaskOperand(llvm::MCInst &Inst, unsigned Val,
808                                      uint64_t Address, const void *Decoder) {
809  // This operand encodes a mask of contiguous zeros between a specified MSB
810  // and LSB.  To decode it, we create the mask of all bits MSB-and-lower,
811  // the mask of all bits LSB-and-lower, and then xor them to create
812  // the mask of that's all ones on [msb, lsb].  Finally we not it to
813  // create the final mask.
814  unsigned msb = fieldFromInstruction32(Val, 5, 5);
815  unsigned lsb = fieldFromInstruction32(Val, 0, 5);
816  uint32_t msb_mask = (1 << (msb+1)) - 1;
817  uint32_t lsb_mask = (1 << lsb) - 1;
818  Inst.addOperand(MCOperand::CreateImm(~(msb_mask ^ lsb_mask)));
819  return true;
820}
821
822static bool DecodeCopMemInstruction(llvm::MCInst &Inst, unsigned Insn,
823                                  uint64_t Address, const void *Decoder) {
824  unsigned pred = fieldFromInstruction32(Insn, 28, 4);
825  unsigned CRd = fieldFromInstruction32(Insn, 12, 4);
826  unsigned coproc = fieldFromInstruction32(Insn, 8, 4);
827  unsigned imm = fieldFromInstruction32(Insn, 0, 8);
828  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
829  unsigned U = fieldFromInstruction32(Insn, 23, 1);
830
831  switch (Inst.getOpcode()) {
832    case ARM::LDC_OFFSET:
833    case ARM::LDC_PRE:
834    case ARM::LDC_POST:
835    case ARM::LDC_OPTION:
836    case ARM::LDCL_OFFSET:
837    case ARM::LDCL_PRE:
838    case ARM::LDCL_POST:
839    case ARM::LDCL_OPTION:
840    case ARM::STC_OFFSET:
841    case ARM::STC_PRE:
842    case ARM::STC_POST:
843    case ARM::STC_OPTION:
844    case ARM::STCL_OFFSET:
845    case ARM::STCL_PRE:
846    case ARM::STCL_POST:
847    case ARM::STCL_OPTION:
848      if (coproc == 0xA || coproc == 0xB)
849        return false;
850      break;
851    default:
852      break;
853  }
854
855  Inst.addOperand(MCOperand::CreateImm(coproc));
856  Inst.addOperand(MCOperand::CreateImm(CRd));
857  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
858  switch (Inst.getOpcode()) {
859    case ARM::LDC_OPTION:
860    case ARM::LDCL_OPTION:
861    case ARM::LDC2_OPTION:
862    case ARM::LDC2L_OPTION:
863    case ARM::STC_OPTION:
864    case ARM::STCL_OPTION:
865    case ARM::STC2_OPTION:
866    case ARM::STC2L_OPTION:
867    case ARM::LDCL_POST:
868    case ARM::STCL_POST:
869      break;
870    default:
871      Inst.addOperand(MCOperand::CreateReg(0));
872      break;
873  }
874
875  unsigned P = fieldFromInstruction32(Insn, 24, 1);
876  unsigned W = fieldFromInstruction32(Insn, 21, 1);
877
878  bool writeback = (P == 0) || (W == 1);
879  unsigned idx_mode = 0;
880  if (P && writeback)
881    idx_mode = ARMII::IndexModePre;
882  else if (!P && writeback)
883    idx_mode = ARMII::IndexModePost;
884
885  switch (Inst.getOpcode()) {
886    case ARM::LDCL_POST:
887    case ARM::STCL_POST:
888      imm |= U << 8;
889    case ARM::LDC_OPTION:
890    case ARM::LDCL_OPTION:
891    case ARM::LDC2_OPTION:
892    case ARM::LDC2L_OPTION:
893    case ARM::STC_OPTION:
894    case ARM::STCL_OPTION:
895    case ARM::STC2_OPTION:
896    case ARM::STC2L_OPTION:
897      Inst.addOperand(MCOperand::CreateImm(imm));
898      break;
899    default:
900      if (U)
901        Inst.addOperand(MCOperand::CreateImm(
902            ARM_AM::getAM2Opc(ARM_AM::add, imm, ARM_AM::lsl, idx_mode)));
903      else
904        Inst.addOperand(MCOperand::CreateImm(
905            ARM_AM::getAM2Opc(ARM_AM::sub, imm, ARM_AM::lsl, idx_mode)));
906      break;
907  }
908
909  switch (Inst.getOpcode()) {
910    case ARM::LDC_OFFSET:
911    case ARM::LDC_PRE:
912    case ARM::LDC_POST:
913    case ARM::LDC_OPTION:
914    case ARM::LDCL_OFFSET:
915    case ARM::LDCL_PRE:
916    case ARM::LDCL_POST:
917    case ARM::LDCL_OPTION:
918    case ARM::STC_OFFSET:
919    case ARM::STC_PRE:
920    case ARM::STC_POST:
921    case ARM::STC_OPTION:
922    case ARM::STCL_OFFSET:
923    case ARM::STCL_PRE:
924    case ARM::STCL_POST:
925    case ARM::STCL_OPTION:
926      if (!DecodePredicateOperand(Inst, pred, Address, Decoder)) return false;
927      break;
928    default:
929      break;
930  }
931
932  return true;
933}
934
935static bool DecodeAddrMode2IdxInstruction(llvm::MCInst &Inst, unsigned Insn,
936                                  uint64_t Address, const void *Decoder) {
937  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
938  unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
939  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
940  unsigned imm = fieldFromInstruction32(Insn, 0, 12);
941  unsigned pred = fieldFromInstruction32(Insn, 28, 4);
942  unsigned reg = fieldFromInstruction32(Insn, 25, 1);
943  unsigned P = fieldFromInstruction32(Insn, 24, 1);
944  unsigned W = fieldFromInstruction32(Insn, 21, 1);
945
946  // On stores, the writeback operand precedes Rt.
947  switch (Inst.getOpcode()) {
948    case ARM::STR_POST_IMM:
949    case ARM::STR_POST_REG:
950    case ARM::STRB_POST_IMM:
951    case ARM::STRB_POST_REG:
952    case ARM::STRT_POST_REG:
953    case ARM::STRT_POST_IMM:
954    case ARM::STRBT_POST_REG:
955    case ARM::STRBT_POST_IMM:
956      if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
957      break;
958    default:
959      break;
960  }
961
962  if (!DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)) return false;
963
964  // On loads, the writeback operand comes after Rt.
965  switch (Inst.getOpcode()) {
966    case ARM::LDR_POST_IMM:
967    case ARM::LDR_POST_REG:
968    case ARM::LDRB_POST_IMM:
969    case ARM::LDRB_POST_REG:
970    case ARM::LDR_PRE:
971    case ARM::LDRB_PRE:
972    case ARM::LDRBT_POST_REG:
973    case ARM::LDRBT_POST_IMM:
974    case ARM::LDRT_POST_REG:
975    case ARM::LDRT_POST_IMM:
976      if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder))
977        return false;
978      break;
979    default:
980      break;
981  }
982
983  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
984
985  ARM_AM::AddrOpc Op = ARM_AM::add;
986  if (!fieldFromInstruction32(Insn, 23, 1))
987    Op = ARM_AM::sub;
988
989  bool writeback = (P == 0) || (W == 1);
990  unsigned idx_mode = 0;
991  if (P && writeback)
992    idx_mode = ARMII::IndexModePre;
993  else if (!P && writeback)
994    idx_mode = ARMII::IndexModePost;
995
996  if (writeback && (Rn == 15 || Rn == Rt)) return false; // UNPREDICTABLE
997
998  if (reg) {
999    if (!DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder)) return false;
1000    ARM_AM::ShiftOpc Opc = ARM_AM::lsl;
1001    switch( fieldFromInstruction32(Insn, 5, 2)) {
1002      case 0:
1003        Opc = ARM_AM::lsl;
1004        break;
1005      case 1:
1006        Opc = ARM_AM::lsr;
1007        break;
1008      case 2:
1009        Opc = ARM_AM::asr;
1010        break;
1011      case 3:
1012        Opc = ARM_AM::ror;
1013        break;
1014      default:
1015        return false;
1016    }
1017    unsigned amt = fieldFromInstruction32(Insn, 7, 5);
1018    unsigned imm = ARM_AM::getAM2Opc(Op, amt, Opc, idx_mode);
1019
1020    Inst.addOperand(MCOperand::CreateImm(imm));
1021  } else {
1022    Inst.addOperand(MCOperand::CreateReg(0));
1023    unsigned tmp = ARM_AM::getAM2Opc(Op, imm, ARM_AM::lsl, idx_mode);
1024    Inst.addOperand(MCOperand::CreateImm(tmp));
1025  }
1026
1027  if (!DecodePredicateOperand(Inst, pred, Address, Decoder)) return false;
1028
1029  return true;
1030}
1031
1032static bool DecodeSORegMemOperand(llvm::MCInst &Inst, unsigned Val,
1033                                  uint64_t Address, const void *Decoder) {
1034  unsigned Rn = fieldFromInstruction32(Val, 13, 4);
1035  unsigned Rm = fieldFromInstruction32(Val,  0, 4);
1036  unsigned type = fieldFromInstruction32(Val, 5, 2);
1037  unsigned imm = fieldFromInstruction32(Val, 7, 5);
1038  unsigned U = fieldFromInstruction32(Val, 12, 1);
1039
1040  ARM_AM::ShiftOpc ShOp = ARM_AM::lsl;
1041  switch (type) {
1042    case 0:
1043      ShOp = ARM_AM::lsl;
1044      break;
1045    case 1:
1046      ShOp = ARM_AM::lsr;
1047      break;
1048    case 2:
1049      ShOp = ARM_AM::asr;
1050      break;
1051    case 3:
1052      ShOp = ARM_AM::ror;
1053      break;
1054  }
1055
1056  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1057  if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
1058  unsigned shift;
1059  if (U)
1060    shift = ARM_AM::getAM2Opc(ARM_AM::add, imm, ShOp);
1061  else
1062    shift = ARM_AM::getAM2Opc(ARM_AM::sub, imm, ShOp);
1063  Inst.addOperand(MCOperand::CreateImm(shift));
1064
1065  return true;
1066}
1067
1068static bool DecodeAddrMode3Instruction(llvm::MCInst &Inst, unsigned Insn,
1069                                  uint64_t Address, const void *Decoder) {
1070  unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
1071  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1072  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1073  unsigned type = fieldFromInstruction32(Insn, 22, 1);
1074  unsigned imm = fieldFromInstruction32(Insn, 8, 4);
1075  unsigned U = ((~fieldFromInstruction32(Insn, 23, 1)) & 1) << 8;
1076  unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1077  unsigned W = fieldFromInstruction32(Insn, 21, 1);
1078  unsigned P = fieldFromInstruction32(Insn, 24, 1);
1079
1080  bool writeback = (W == 1) | (P == 0);
1081  if (writeback) { // Writeback
1082    if (P)
1083      U |= ARMII::IndexModePre << 9;
1084    else
1085      U |= ARMII::IndexModePost << 9;
1086
1087    // On stores, the writeback operand precedes Rt.
1088    switch (Inst.getOpcode()) {
1089    case ARM::STRD:
1090    case ARM::STRD_PRE:
1091    case ARM::STRD_POST:
1092    case ARM::STRH:
1093    case ARM::STRH_PRE:
1094    case ARM::STRH_POST:
1095      if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder))
1096        return false;
1097      break;
1098    default:
1099      break;
1100    }
1101  }
1102
1103  if (!DecodeGPRRegisterClass(Inst, Rt, Address, Decoder))
1104    return false;
1105  switch (Inst.getOpcode()) {
1106    case ARM::STRD:
1107    case ARM::STRD_PRE:
1108    case ARM::STRD_POST:
1109    case ARM::LDRD:
1110    case ARM::LDRD_PRE:
1111    case ARM::LDRD_POST:
1112      if (!DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder))
1113        return false;
1114      break;
1115    default:
1116      break;
1117  }
1118
1119  if (writeback) {
1120    // On loads, the writeback operand comes after Rt.
1121    switch (Inst.getOpcode()) {
1122    case ARM::LDRD:
1123    case ARM::LDRD_PRE:
1124    case ARM::LDRD_POST:
1125    case ARM::LDRH:
1126    case ARM::LDRH_PRE:
1127    case ARM::LDRH_POST:
1128    case ARM::LDRSH:
1129    case ARM::LDRSH_PRE:
1130    case ARM::LDRSH_POST:
1131    case ARM::LDRSB:
1132    case ARM::LDRSB_PRE:
1133    case ARM::LDRSB_POST:
1134    case ARM::LDRHTr:
1135    case ARM::LDRSBTr:
1136      if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder))
1137        return false;
1138      break;
1139    default:
1140      break;
1141    }
1142  }
1143
1144  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder))
1145    return false;
1146
1147  if (type) {
1148    Inst.addOperand(MCOperand::CreateReg(0));
1149    Inst.addOperand(MCOperand::CreateImm(U | (imm << 4) | Rm));
1150  } else {
1151    if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder))
1152      return false;
1153    Inst.addOperand(MCOperand::CreateImm(U));
1154  }
1155
1156  if (!DecodePredicateOperand(Inst, pred, Address, Decoder)) return false;
1157
1158  return true;
1159}
1160
1161static bool DecodeRFEInstruction(llvm::MCInst &Inst, unsigned Insn,
1162                                 uint64_t Address, const void *Decoder) {
1163  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1164  unsigned mode = fieldFromInstruction32(Insn, 23, 2);
1165
1166  switch (mode) {
1167    case 0:
1168      mode = ARM_AM::da;
1169      break;
1170    case 1:
1171      mode = ARM_AM::ia;
1172      break;
1173    case 2:
1174      mode = ARM_AM::db;
1175      break;
1176    case 3:
1177      mode = ARM_AM::ib;
1178      break;
1179  }
1180
1181  Inst.addOperand(MCOperand::CreateImm(mode));
1182  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1183
1184  return true;
1185}
1186
1187static bool DecodeMemMultipleWritebackInstruction(llvm::MCInst &Inst,
1188                                  unsigned Insn,
1189                                  uint64_t Address, const void *Decoder) {
1190  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1191  unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1192  unsigned reglist = fieldFromInstruction32(Insn, 0, 16);
1193
1194  if (pred == 0xF) {
1195    switch (Inst.getOpcode()) {
1196      case ARM::STMDA:
1197        Inst.setOpcode(ARM::RFEDA);
1198        break;
1199      case ARM::STMDA_UPD:
1200        Inst.setOpcode(ARM::RFEDA_UPD);
1201        break;
1202      case ARM::STMDB:
1203        Inst.setOpcode(ARM::RFEDB);
1204        break;
1205      case ARM::STMDB_UPD:
1206        Inst.setOpcode(ARM::RFEDB_UPD);
1207        break;
1208      case ARM::STMIA:
1209        Inst.setOpcode(ARM::RFEIA);
1210        break;
1211      case ARM::STMIA_UPD:
1212        Inst.setOpcode(ARM::RFEIA_UPD);
1213        break;
1214      case ARM::STMIB:
1215        Inst.setOpcode(ARM::RFEIB);
1216        break;
1217      case ARM::STMIB_UPD:
1218        Inst.setOpcode(ARM::RFEIB_UPD);
1219        break;
1220    }
1221    return DecodeRFEInstruction(Inst, Insn, Address, Decoder);
1222  }
1223
1224  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)   ||
1225      !DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)   || // Tied
1226      !DecodePredicateOperand(Inst, pred, Address, Decoder) ||
1227      !DecodeRegListOperand(Inst, reglist, Address, Decoder))
1228    return false;
1229
1230  return true;
1231}
1232
1233static bool DecodeCPSInstruction(llvm::MCInst &Inst, unsigned Insn,
1234                                 uint64_t Address, const void *Decoder) {
1235  unsigned imod = fieldFromInstruction32(Insn, 18, 2);
1236  unsigned M = fieldFromInstruction32(Insn, 17, 1);
1237  unsigned iflags = fieldFromInstruction32(Insn, 6, 3);
1238  unsigned mode = fieldFromInstruction32(Insn, 0, 5);
1239
1240  // imod == '01' --> UNPREDICTABLE
1241  if (imod == 1) return false;
1242
1243  if (M && mode && imod && iflags) {
1244    Inst.setOpcode(ARM::CPS3p);
1245    Inst.addOperand(MCOperand::CreateImm(imod));
1246    Inst.addOperand(MCOperand::CreateImm(iflags));
1247    Inst.addOperand(MCOperand::CreateImm(mode));
1248    return true;
1249  } else if (!mode && !M) {
1250    Inst.setOpcode(ARM::CPS2p);
1251    Inst.addOperand(MCOperand::CreateImm(imod));
1252    Inst.addOperand(MCOperand::CreateImm(iflags));
1253    return true;
1254  } else if (!imod && !iflags && M) {
1255    Inst.setOpcode(ARM::CPS1p);
1256    Inst.addOperand(MCOperand::CreateImm(mode));
1257    return true;
1258  }
1259
1260  return false;
1261}
1262
1263static bool DecodeSMLAInstruction(llvm::MCInst &Inst, unsigned Insn,
1264                                 uint64_t Address, const void *Decoder) {
1265  unsigned Rd = fieldFromInstruction32(Insn, 16, 4);
1266  unsigned Rn = fieldFromInstruction32(Insn, 0, 4);
1267  unsigned Rm = fieldFromInstruction32(Insn, 8, 4);
1268  unsigned Ra = fieldFromInstruction32(Insn, 12, 4);
1269  unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1270
1271  if (pred == 0xF)
1272    return DecodeCPSInstruction(Inst, Insn, Address, Decoder);
1273
1274  if (!DecodeGPRnopcRegisterClass(Inst, Rd, Address, Decoder) ||
1275      !DecodeGPRnopcRegisterClass(Inst, Rn, Address, Decoder) ||
1276      !DecodeGPRnopcRegisterClass(Inst, Rm, Address, Decoder) ||
1277      !DecodeGPRnopcRegisterClass(Inst, Ra, Address, Decoder))
1278    return false;
1279
1280  if (!DecodePredicateOperand(Inst, pred, Address, Decoder)) return false;
1281
1282  return true;
1283}
1284
1285static bool DecodeAddrModeImm12Operand(llvm::MCInst &Inst, unsigned Val,
1286                           uint64_t Address, const void *Decoder) {
1287  unsigned add = fieldFromInstruction32(Val, 12, 1);
1288  unsigned imm = fieldFromInstruction32(Val, 0, 12);
1289  unsigned Rn = fieldFromInstruction32(Val, 13, 4);
1290
1291  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder))
1292    return false;
1293
1294  if (!add) imm *= -1;
1295  if (imm == 0 && !add) imm = INT32_MIN;
1296  Inst.addOperand(MCOperand::CreateImm(imm));
1297
1298  return true;
1299}
1300
1301static bool DecodeAddrMode5Operand(llvm::MCInst &Inst, unsigned Val,
1302                                   uint64_t Address, const void *Decoder) {
1303  unsigned Rn = fieldFromInstruction32(Val, 9, 4);
1304  unsigned U = fieldFromInstruction32(Val, 8, 1);
1305  unsigned imm = fieldFromInstruction32(Val, 0, 8);
1306
1307  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder))
1308    return false;
1309
1310  if (U)
1311    Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::add, imm)));
1312  else
1313    Inst.addOperand(MCOperand::CreateImm(ARM_AM::getAM5Opc(ARM_AM::sub, imm)));
1314
1315  return true;
1316}
1317
1318static bool DecodeAddrMode7Operand(llvm::MCInst &Inst, unsigned Val,
1319                                   uint64_t Address, const void *Decoder) {
1320  return DecodeGPRRegisterClass(Inst, Val, Address, Decoder);
1321}
1322
1323static bool DecodeBranchImmInstruction(llvm::MCInst &Inst, unsigned Insn,
1324                                   uint64_t Address, const void *Decoder) {
1325  unsigned pred = fieldFromInstruction32(Insn, 28, 4);
1326  unsigned imm = fieldFromInstruction32(Insn, 0, 24) << 2;
1327
1328  if (pred == 0xF) {
1329    Inst.setOpcode(ARM::BLXi);
1330    imm |= fieldFromInstruction32(Insn, 24, 1) << 1;
1331    Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1332    return true;
1333  }
1334
1335  Inst.addOperand(MCOperand::CreateImm(SignExtend32<26>(imm)));
1336  if (!DecodePredicateOperand(Inst, pred, Address, Decoder)) return false;
1337
1338  return true;
1339}
1340
1341
1342static bool DecodeVCVTImmOperand(llvm::MCInst &Inst, unsigned Val,
1343                                 uint64_t Address, const void *Decoder) {
1344  Inst.addOperand(MCOperand::CreateImm(64 - Val));
1345  return true;
1346}
1347
1348static bool DecodeAddrMode6Operand(llvm::MCInst &Inst, unsigned Val,
1349                                   uint64_t Address, const void *Decoder) {
1350  unsigned Rm = fieldFromInstruction32(Val, 0, 4);
1351  unsigned align = fieldFromInstruction32(Val, 4, 2);
1352
1353  if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder))
1354    return false;
1355  if (!align)
1356    Inst.addOperand(MCOperand::CreateImm(0));
1357  else
1358    Inst.addOperand(MCOperand::CreateImm(4 << align));
1359
1360  return true;
1361}
1362
1363static bool DecodeVLDInstruction(llvm::MCInst &Inst, unsigned Insn,
1364                                   uint64_t Address, const void *Decoder) {
1365  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1366  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1367  unsigned wb = fieldFromInstruction32(Insn, 16, 4);
1368  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1369  Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
1370  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1371
1372  // First output register
1373  if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
1374
1375  // Second output register
1376  switch (Inst.getOpcode()) {
1377    case ARM::VLD1q8:
1378    case ARM::VLD1q16:
1379    case ARM::VLD1q32:
1380    case ARM::VLD1q64:
1381    case ARM::VLD1q8_UPD:
1382    case ARM::VLD1q16_UPD:
1383    case ARM::VLD1q32_UPD:
1384    case ARM::VLD1q64_UPD:
1385    case ARM::VLD1d8T:
1386    case ARM::VLD1d16T:
1387    case ARM::VLD1d32T:
1388    case ARM::VLD1d64T:
1389    case ARM::VLD1d8T_UPD:
1390    case ARM::VLD1d16T_UPD:
1391    case ARM::VLD1d32T_UPD:
1392    case ARM::VLD1d64T_UPD:
1393    case ARM::VLD1d8Q:
1394    case ARM::VLD1d16Q:
1395    case ARM::VLD1d32Q:
1396    case ARM::VLD1d64Q:
1397    case ARM::VLD1d8Q_UPD:
1398    case ARM::VLD1d16Q_UPD:
1399    case ARM::VLD1d32Q_UPD:
1400    case ARM::VLD1d64Q_UPD:
1401    case ARM::VLD2d8:
1402    case ARM::VLD2d16:
1403    case ARM::VLD2d32:
1404    case ARM::VLD2d8_UPD:
1405    case ARM::VLD2d16_UPD:
1406    case ARM::VLD2d32_UPD:
1407    case ARM::VLD2q8:
1408    case ARM::VLD2q16:
1409    case ARM::VLD2q32:
1410    case ARM::VLD2q8_UPD:
1411    case ARM::VLD2q16_UPD:
1412    case ARM::VLD2q32_UPD:
1413    case ARM::VLD3d8:
1414    case ARM::VLD3d16:
1415    case ARM::VLD3d32:
1416    case ARM::VLD3d8_UPD:
1417    case ARM::VLD3d16_UPD:
1418    case ARM::VLD3d32_UPD:
1419    case ARM::VLD4d8:
1420    case ARM::VLD4d16:
1421    case ARM::VLD4d32:
1422    case ARM::VLD4d8_UPD:
1423    case ARM::VLD4d16_UPD:
1424    case ARM::VLD4d32_UPD:
1425      if (!DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)) return false;
1426      break;
1427    case ARM::VLD2b8:
1428    case ARM::VLD2b16:
1429    case ARM::VLD2b32:
1430    case ARM::VLD2b8_UPD:
1431    case ARM::VLD2b16_UPD:
1432    case ARM::VLD2b32_UPD:
1433    case ARM::VLD3q8:
1434    case ARM::VLD3q16:
1435    case ARM::VLD3q32:
1436    case ARM::VLD3q8_UPD:
1437    case ARM::VLD3q16_UPD:
1438    case ARM::VLD3q32_UPD:
1439    case ARM::VLD4q8:
1440    case ARM::VLD4q16:
1441    case ARM::VLD4q32:
1442    case ARM::VLD4q8_UPD:
1443    case ARM::VLD4q16_UPD:
1444    case ARM::VLD4q32_UPD:
1445      if (!DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)) return false;
1446    default:
1447      break;
1448  }
1449
1450  // Third output register
1451  switch(Inst.getOpcode()) {
1452    case ARM::VLD1d8T:
1453    case ARM::VLD1d16T:
1454    case ARM::VLD1d32T:
1455    case ARM::VLD1d64T:
1456    case ARM::VLD1d8T_UPD:
1457    case ARM::VLD1d16T_UPD:
1458    case ARM::VLD1d32T_UPD:
1459    case ARM::VLD1d64T_UPD:
1460    case ARM::VLD1d8Q:
1461    case ARM::VLD1d16Q:
1462    case ARM::VLD1d32Q:
1463    case ARM::VLD1d64Q:
1464    case ARM::VLD1d8Q_UPD:
1465    case ARM::VLD1d16Q_UPD:
1466    case ARM::VLD1d32Q_UPD:
1467    case ARM::VLD1d64Q_UPD:
1468    case ARM::VLD2q8:
1469    case ARM::VLD2q16:
1470    case ARM::VLD2q32:
1471    case ARM::VLD2q8_UPD:
1472    case ARM::VLD2q16_UPD:
1473    case ARM::VLD2q32_UPD:
1474    case ARM::VLD3d8:
1475    case ARM::VLD3d16:
1476    case ARM::VLD3d32:
1477    case ARM::VLD3d8_UPD:
1478    case ARM::VLD3d16_UPD:
1479    case ARM::VLD3d32_UPD:
1480    case ARM::VLD4d8:
1481    case ARM::VLD4d16:
1482    case ARM::VLD4d32:
1483    case ARM::VLD4d8_UPD:
1484    case ARM::VLD4d16_UPD:
1485    case ARM::VLD4d32_UPD:
1486      if (!DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)) return false;
1487      break;
1488    case ARM::VLD3q8:
1489    case ARM::VLD3q16:
1490    case ARM::VLD3q32:
1491    case ARM::VLD3q8_UPD:
1492    case ARM::VLD3q16_UPD:
1493    case ARM::VLD3q32_UPD:
1494    case ARM::VLD4q8:
1495    case ARM::VLD4q16:
1496    case ARM::VLD4q32:
1497    case ARM::VLD4q8_UPD:
1498    case ARM::VLD4q16_UPD:
1499    case ARM::VLD4q32_UPD:
1500      if (!DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)) return false;
1501      break;
1502    default:
1503      break;
1504  }
1505
1506  // Fourth output register
1507  switch (Inst.getOpcode()) {
1508    case ARM::VLD1d8Q:
1509    case ARM::VLD1d16Q:
1510    case ARM::VLD1d32Q:
1511    case ARM::VLD1d64Q:
1512    case ARM::VLD1d8Q_UPD:
1513    case ARM::VLD1d16Q_UPD:
1514    case ARM::VLD1d32Q_UPD:
1515    case ARM::VLD1d64Q_UPD:
1516    case ARM::VLD2q8:
1517    case ARM::VLD2q16:
1518    case ARM::VLD2q32:
1519    case ARM::VLD2q8_UPD:
1520    case ARM::VLD2q16_UPD:
1521    case ARM::VLD2q32_UPD:
1522    case ARM::VLD4d8:
1523    case ARM::VLD4d16:
1524    case ARM::VLD4d32:
1525    case ARM::VLD4d8_UPD:
1526    case ARM::VLD4d16_UPD:
1527    case ARM::VLD4d32_UPD:
1528      if (!DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)) return false;
1529      break;
1530    case ARM::VLD4q8:
1531    case ARM::VLD4q16:
1532    case ARM::VLD4q32:
1533    case ARM::VLD4q8_UPD:
1534    case ARM::VLD4q16_UPD:
1535    case ARM::VLD4q32_UPD:
1536      if (!DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)) return false;
1537      break;
1538    default:
1539      break;
1540  }
1541
1542  // Writeback operand
1543  switch (Inst.getOpcode()) {
1544    case ARM::VLD1d8_UPD:
1545    case ARM::VLD1d16_UPD:
1546    case ARM::VLD1d32_UPD:
1547    case ARM::VLD1d64_UPD:
1548    case ARM::VLD1q8_UPD:
1549    case ARM::VLD1q16_UPD:
1550    case ARM::VLD1q32_UPD:
1551    case ARM::VLD1q64_UPD:
1552    case ARM::VLD1d8T_UPD:
1553    case ARM::VLD1d16T_UPD:
1554    case ARM::VLD1d32T_UPD:
1555    case ARM::VLD1d64T_UPD:
1556    case ARM::VLD1d8Q_UPD:
1557    case ARM::VLD1d16Q_UPD:
1558    case ARM::VLD1d32Q_UPD:
1559    case ARM::VLD1d64Q_UPD:
1560    case ARM::VLD2d8_UPD:
1561    case ARM::VLD2d16_UPD:
1562    case ARM::VLD2d32_UPD:
1563    case ARM::VLD2q8_UPD:
1564    case ARM::VLD2q16_UPD:
1565    case ARM::VLD2q32_UPD:
1566    case ARM::VLD2b8_UPD:
1567    case ARM::VLD2b16_UPD:
1568    case ARM::VLD2b32_UPD:
1569    case ARM::VLD3d8_UPD:
1570    case ARM::VLD3d16_UPD:
1571    case ARM::VLD3d32_UPD:
1572    case ARM::VLD3q8_UPD:
1573    case ARM::VLD3q16_UPD:
1574    case ARM::VLD3q32_UPD:
1575    case ARM::VLD4d8_UPD:
1576    case ARM::VLD4d16_UPD:
1577    case ARM::VLD4d32_UPD:
1578    case ARM::VLD4q8_UPD:
1579    case ARM::VLD4q16_UPD:
1580    case ARM::VLD4q32_UPD:
1581      if (!DecodeGPRRegisterClass(Inst, wb, Address, Decoder)) return false;
1582      break;
1583    default:
1584      break;
1585  }
1586
1587  // AddrMode6 Base (register+alignment)
1588  if (!DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)) return false;
1589
1590  // AddrMode6 Offset (register)
1591  if (Rm == 0xD)
1592    Inst.addOperand(MCOperand::CreateReg(0));
1593  else if (Rm != 0xF) {
1594    if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder))
1595      return false;
1596  }
1597
1598  return true;
1599}
1600
1601static bool DecodeVSTInstruction(llvm::MCInst &Inst, unsigned Insn,
1602                                 uint64_t Address, const void *Decoder) {
1603  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1604  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1605  unsigned wb = fieldFromInstruction32(Insn, 16, 4);
1606  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1607  Rn |= fieldFromInstruction32(Insn, 4, 2) << 4;
1608  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1609
1610  // Writeback Operand
1611  switch (Inst.getOpcode()) {
1612    case ARM::VST1d8_UPD:
1613    case ARM::VST1d16_UPD:
1614    case ARM::VST1d32_UPD:
1615    case ARM::VST1d64_UPD:
1616    case ARM::VST1q8_UPD:
1617    case ARM::VST1q16_UPD:
1618    case ARM::VST1q32_UPD:
1619    case ARM::VST1q64_UPD:
1620    case ARM::VST1d8T_UPD:
1621    case ARM::VST1d16T_UPD:
1622    case ARM::VST1d32T_UPD:
1623    case ARM::VST1d64T_UPD:
1624    case ARM::VST1d8Q_UPD:
1625    case ARM::VST1d16Q_UPD:
1626    case ARM::VST1d32Q_UPD:
1627    case ARM::VST1d64Q_UPD:
1628    case ARM::VST2d8_UPD:
1629    case ARM::VST2d16_UPD:
1630    case ARM::VST2d32_UPD:
1631    case ARM::VST2q8_UPD:
1632    case ARM::VST2q16_UPD:
1633    case ARM::VST2q32_UPD:
1634    case ARM::VST2b8_UPD:
1635    case ARM::VST2b16_UPD:
1636    case ARM::VST2b32_UPD:
1637    case ARM::VST3d8_UPD:
1638    case ARM::VST3d16_UPD:
1639    case ARM::VST3d32_UPD:
1640    case ARM::VST3q8_UPD:
1641    case ARM::VST3q16_UPD:
1642    case ARM::VST3q32_UPD:
1643    case ARM::VST4d8_UPD:
1644    case ARM::VST4d16_UPD:
1645    case ARM::VST4d32_UPD:
1646    case ARM::VST4q8_UPD:
1647    case ARM::VST4q16_UPD:
1648    case ARM::VST4q32_UPD:
1649      if (!DecodeGPRRegisterClass(Inst, wb, Address, Decoder))
1650        return false;
1651      break;
1652    default:
1653      break;
1654  }
1655
1656  // AddrMode6 Base (register+alignment)
1657  if (!DecodeAddrMode6Operand(Inst, Rn, Address, Decoder)) return false;
1658
1659  // AddrMode6 Offset (register)
1660  if (Rm == 0xD)
1661    Inst.addOperand(MCOperand::CreateReg(0));
1662  else if (Rm != 0xF) {
1663    if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
1664  }
1665
1666  // First input register
1667  if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
1668
1669  // Second input register
1670  switch (Inst.getOpcode()) {
1671    case ARM::VST1q8:
1672    case ARM::VST1q16:
1673    case ARM::VST1q32:
1674    case ARM::VST1q64:
1675    case ARM::VST1q8_UPD:
1676    case ARM::VST1q16_UPD:
1677    case ARM::VST1q32_UPD:
1678    case ARM::VST1q64_UPD:
1679    case ARM::VST1d8T:
1680    case ARM::VST1d16T:
1681    case ARM::VST1d32T:
1682    case ARM::VST1d64T:
1683    case ARM::VST1d8T_UPD:
1684    case ARM::VST1d16T_UPD:
1685    case ARM::VST1d32T_UPD:
1686    case ARM::VST1d64T_UPD:
1687    case ARM::VST1d8Q:
1688    case ARM::VST1d16Q:
1689    case ARM::VST1d32Q:
1690    case ARM::VST1d64Q:
1691    case ARM::VST1d8Q_UPD:
1692    case ARM::VST1d16Q_UPD:
1693    case ARM::VST1d32Q_UPD:
1694    case ARM::VST1d64Q_UPD:
1695    case ARM::VST2d8:
1696    case ARM::VST2d16:
1697    case ARM::VST2d32:
1698    case ARM::VST2d8_UPD:
1699    case ARM::VST2d16_UPD:
1700    case ARM::VST2d32_UPD:
1701    case ARM::VST2q8:
1702    case ARM::VST2q16:
1703    case ARM::VST2q32:
1704    case ARM::VST2q8_UPD:
1705    case ARM::VST2q16_UPD:
1706    case ARM::VST2q32_UPD:
1707    case ARM::VST3d8:
1708    case ARM::VST3d16:
1709    case ARM::VST3d32:
1710    case ARM::VST3d8_UPD:
1711    case ARM::VST3d16_UPD:
1712    case ARM::VST3d32_UPD:
1713    case ARM::VST4d8:
1714    case ARM::VST4d16:
1715    case ARM::VST4d32:
1716    case ARM::VST4d8_UPD:
1717    case ARM::VST4d16_UPD:
1718    case ARM::VST4d32_UPD:
1719      if (!DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)) return false;
1720      break;
1721    case ARM::VST2b8:
1722    case ARM::VST2b16:
1723    case ARM::VST2b32:
1724    case ARM::VST2b8_UPD:
1725    case ARM::VST2b16_UPD:
1726    case ARM::VST2b32_UPD:
1727    case ARM::VST3q8:
1728    case ARM::VST3q16:
1729    case ARM::VST3q32:
1730    case ARM::VST3q8_UPD:
1731    case ARM::VST3q16_UPD:
1732    case ARM::VST3q32_UPD:
1733    case ARM::VST4q8:
1734    case ARM::VST4q16:
1735    case ARM::VST4q32:
1736    case ARM::VST4q8_UPD:
1737    case ARM::VST4q16_UPD:
1738    case ARM::VST4q32_UPD:
1739      if (!DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)) return false;
1740      break;
1741    default:
1742      break;
1743  }
1744
1745  // Third input register
1746  switch (Inst.getOpcode()) {
1747    case ARM::VST1d8T:
1748    case ARM::VST1d16T:
1749    case ARM::VST1d32T:
1750    case ARM::VST1d64T:
1751    case ARM::VST1d8T_UPD:
1752    case ARM::VST1d16T_UPD:
1753    case ARM::VST1d32T_UPD:
1754    case ARM::VST1d64T_UPD:
1755    case ARM::VST1d8Q:
1756    case ARM::VST1d16Q:
1757    case ARM::VST1d32Q:
1758    case ARM::VST1d64Q:
1759    case ARM::VST1d8Q_UPD:
1760    case ARM::VST1d16Q_UPD:
1761    case ARM::VST1d32Q_UPD:
1762    case ARM::VST1d64Q_UPD:
1763    case ARM::VST2q8:
1764    case ARM::VST2q16:
1765    case ARM::VST2q32:
1766    case ARM::VST2q8_UPD:
1767    case ARM::VST2q16_UPD:
1768    case ARM::VST2q32_UPD:
1769    case ARM::VST3d8:
1770    case ARM::VST3d16:
1771    case ARM::VST3d32:
1772    case ARM::VST3d8_UPD:
1773    case ARM::VST3d16_UPD:
1774    case ARM::VST3d32_UPD:
1775    case ARM::VST4d8:
1776    case ARM::VST4d16:
1777    case ARM::VST4d32:
1778    case ARM::VST4d8_UPD:
1779    case ARM::VST4d16_UPD:
1780    case ARM::VST4d32_UPD:
1781      if (!DecodeDPRRegisterClass(Inst, (Rd+2)%32, Address, Decoder)) return false;
1782      break;
1783    case ARM::VST3q8:
1784    case ARM::VST3q16:
1785    case ARM::VST3q32:
1786    case ARM::VST3q8_UPD:
1787    case ARM::VST3q16_UPD:
1788    case ARM::VST3q32_UPD:
1789    case ARM::VST4q8:
1790    case ARM::VST4q16:
1791    case ARM::VST4q32:
1792    case ARM::VST4q8_UPD:
1793    case ARM::VST4q16_UPD:
1794    case ARM::VST4q32_UPD:
1795      if (!DecodeDPRRegisterClass(Inst, (Rd+4)%32, Address, Decoder)) return false;
1796      break;
1797    default:
1798      break;
1799  }
1800
1801  // Fourth input register
1802  switch (Inst.getOpcode()) {
1803    case ARM::VST1d8Q:
1804    case ARM::VST1d16Q:
1805    case ARM::VST1d32Q:
1806    case ARM::VST1d64Q:
1807    case ARM::VST1d8Q_UPD:
1808    case ARM::VST1d16Q_UPD:
1809    case ARM::VST1d32Q_UPD:
1810    case ARM::VST1d64Q_UPD:
1811    case ARM::VST2q8:
1812    case ARM::VST2q16:
1813    case ARM::VST2q32:
1814    case ARM::VST2q8_UPD:
1815    case ARM::VST2q16_UPD:
1816    case ARM::VST2q32_UPD:
1817    case ARM::VST4d8:
1818    case ARM::VST4d16:
1819    case ARM::VST4d32:
1820    case ARM::VST4d8_UPD:
1821    case ARM::VST4d16_UPD:
1822    case ARM::VST4d32_UPD:
1823      if (!DecodeDPRRegisterClass(Inst, (Rd+3)%32, Address, Decoder)) return false;
1824      break;
1825    case ARM::VST4q8:
1826    case ARM::VST4q16:
1827    case ARM::VST4q32:
1828    case ARM::VST4q8_UPD:
1829    case ARM::VST4q16_UPD:
1830    case ARM::VST4q32_UPD:
1831      if (!DecodeDPRRegisterClass(Inst, (Rd+6)%32, Address, Decoder)) return false;
1832      break;
1833    default:
1834      break;
1835  }
1836
1837  return true;
1838}
1839
1840static bool DecodeVLD1DupInstruction(llvm::MCInst &Inst, unsigned Insn,
1841                                    uint64_t Address, const void *Decoder) {
1842  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1843  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1844  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1845  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1846  unsigned align = fieldFromInstruction32(Insn, 4, 1);
1847  unsigned size = fieldFromInstruction32(Insn, 6, 2);
1848  unsigned regs = fieldFromInstruction32(Insn, 5, 1) + 1;
1849
1850  align *= (1 << size);
1851
1852  if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
1853  if (regs == 2) {
1854    if (!DecodeDPRRegisterClass(Inst, (Rd+1)%32, Address, Decoder)) return false;
1855  }
1856  if (Rm == 0xD) {
1857    if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1858  }
1859
1860  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1861  Inst.addOperand(MCOperand::CreateImm(align));
1862
1863  if (Rm == 0xD)
1864    Inst.addOperand(MCOperand::CreateReg(0));
1865  else if (Rm != 0xF) {
1866    if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
1867  }
1868
1869  return true;
1870}
1871
1872static bool DecodeVLD2DupInstruction(llvm::MCInst &Inst, unsigned Insn,
1873                                    uint64_t Address, const void *Decoder) {
1874  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1875  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1876  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1877  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1878  unsigned align = fieldFromInstruction32(Insn, 4, 1);
1879  unsigned size = 1 << fieldFromInstruction32(Insn, 6, 2);
1880  unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
1881  align *= 2*size;
1882
1883  if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
1884  if (!DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)) return false;
1885  if (Rm == 0xD) {
1886    if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1887  }
1888
1889  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1890  Inst.addOperand(MCOperand::CreateImm(align));
1891
1892  if (Rm == 0xD)
1893    Inst.addOperand(MCOperand::CreateReg(0));
1894  else if (Rm != 0xF) {
1895    if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
1896  }
1897
1898  return true;
1899}
1900
1901static bool DecodeVLD3DupInstruction(llvm::MCInst &Inst, unsigned Insn,
1902                                    uint64_t Address, const void *Decoder) {
1903  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1904  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1905  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1906  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1907  unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
1908
1909  if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)          ||
1910      !DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder) ||
1911      !DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder))
1912    return false;
1913  if (Rm == 0xD) {
1914    if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1915  }
1916
1917  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1918  Inst.addOperand(MCOperand::CreateImm(0));
1919
1920  if (Rm == 0xD)
1921    Inst.addOperand(MCOperand::CreateReg(0));
1922  else if (Rm != 0xF) {
1923    if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
1924  }
1925
1926  return true;
1927}
1928
1929static bool DecodeVLD4DupInstruction(llvm::MCInst &Inst, unsigned Insn,
1930                                    uint64_t Address, const void *Decoder) {
1931  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1932  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1933  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
1934  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
1935  unsigned size = fieldFromInstruction32(Insn, 6, 2);
1936  unsigned inc = fieldFromInstruction32(Insn, 5, 1) + 1;
1937  unsigned align = fieldFromInstruction32(Insn, 4, 1);
1938
1939  if (size == 0x3) {
1940    size = 4;
1941    align = 16;
1942  } else {
1943    if (size == 2) {
1944      size = 1 << size;
1945      align *= 8;
1946    } else {
1947      size = 1 << size;
1948      align *= 4*size;
1949    }
1950  }
1951
1952  if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)            ||
1953      !DecodeDPRRegisterClass(Inst, (Rd+inc)%32, Address, Decoder)   ||
1954      !DecodeDPRRegisterClass(Inst, (Rd+2*inc)%32, Address, Decoder) ||
1955      !DecodeDPRRegisterClass(Inst, (Rd+3*inc)%32, Address, Decoder))
1956    return false;
1957  if (Rm == 0xD) {
1958    if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1959  }
1960
1961  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
1962  Inst.addOperand(MCOperand::CreateImm(align));
1963
1964  if (Rm == 0xD)
1965    Inst.addOperand(MCOperand::CreateReg(0));
1966  else if (Rm != 0xF) {
1967    if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
1968  }
1969
1970  return true;
1971}
1972
1973static bool DecodeNEONModImmInstruction(llvm::MCInst &Inst, unsigned Insn,
1974                                        uint64_t Address, const void *Decoder) {
1975  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
1976  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
1977  unsigned imm = fieldFromInstruction32(Insn, 0, 4);
1978  imm |= fieldFromInstruction32(Insn, 16, 3) << 4;
1979  imm |= fieldFromInstruction32(Insn, 24, 1) << 7;
1980  imm |= fieldFromInstruction32(Insn, 8, 4) << 8;
1981  imm |= fieldFromInstruction32(Insn, 5, 1) << 12;
1982  unsigned Q = fieldFromInstruction32(Insn, 6, 1);
1983
1984  if (Q) {
1985    if (!DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
1986  } else {
1987    if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
1988  }
1989
1990  Inst.addOperand(MCOperand::CreateImm(imm));
1991
1992  switch (Inst.getOpcode()) {
1993    case ARM::VORRiv4i16:
1994    case ARM::VORRiv2i32:
1995    case ARM::VBICiv4i16:
1996    case ARM::VBICiv2i32:
1997      if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
1998      break;
1999    case ARM::VORRiv8i16:
2000    case ARM::VORRiv4i32:
2001    case ARM::VBICiv8i16:
2002    case ARM::VBICiv4i32:
2003      if (!DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
2004      break;
2005    default:
2006      break;
2007  }
2008
2009  return true;
2010}
2011
2012static bool DecodeVSHLMaxInstruction(llvm::MCInst &Inst, unsigned Insn,
2013                                        uint64_t Address, const void *Decoder) {
2014  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2015  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2016  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2017  Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2018  unsigned size = fieldFromInstruction32(Insn, 18, 2);
2019
2020  if (!DecodeQPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
2021  if (!DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
2022  Inst.addOperand(MCOperand::CreateImm(8 << size));
2023
2024  return true;
2025}
2026
2027static bool DecodeShiftRight8Imm(llvm::MCInst &Inst, unsigned Val,
2028                               uint64_t Address, const void *Decoder) {
2029  Inst.addOperand(MCOperand::CreateImm(8 - Val));
2030  return true;
2031}
2032
2033static bool DecodeShiftRight16Imm(llvm::MCInst &Inst, unsigned Val,
2034                               uint64_t Address, const void *Decoder) {
2035  Inst.addOperand(MCOperand::CreateImm(16 - Val));
2036  return true;
2037}
2038
2039static bool DecodeShiftRight32Imm(llvm::MCInst &Inst, unsigned Val,
2040                               uint64_t Address, const void *Decoder) {
2041  Inst.addOperand(MCOperand::CreateImm(32 - Val));
2042  return true;
2043}
2044
2045static bool DecodeShiftRight64Imm(llvm::MCInst &Inst, unsigned Val,
2046                               uint64_t Address, const void *Decoder) {
2047  Inst.addOperand(MCOperand::CreateImm(64 - Val));
2048  return true;
2049}
2050
2051static bool DecodeTBLInstruction(llvm::MCInst &Inst, unsigned Insn,
2052                               uint64_t Address, const void *Decoder) {
2053  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2054  Rd |= fieldFromInstruction32(Insn, 22, 1) << 4;
2055  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2056  Rn |= fieldFromInstruction32(Insn, 7, 1) << 4;
2057  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2058  Rm |= fieldFromInstruction32(Insn, 5, 1) << 4;
2059  unsigned op = fieldFromInstruction32(Insn, 6, 1);
2060  unsigned length = fieldFromInstruction32(Insn, 8, 2) + 1;
2061
2062  if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
2063  if (op) {
2064    if (!DecodeDPRRegisterClass(Inst, Rd, Address, Decoder)) return false; // Writeback
2065  }
2066
2067  for (unsigned i = 0; i < length; ++i) {
2068    if (!DecodeDPRRegisterClass(Inst, (Rn+i)%32, Address, Decoder)) return false;
2069  }
2070
2071  if (!DecodeDPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
2072
2073  return true;
2074}
2075
2076static bool DecodeVFPfpImm(llvm::MCInst &Inst, unsigned Val,
2077                            uint64_t Address, const void *Decoder) {
2078  // The immediate needs to be a fully instantiated float.  However, the
2079  // auto-generated decoder is only able to fill in some of the bits
2080  // necessary.  For instance, the 'b' bit is replicated multiple times,
2081  // and is even present in inverted form in one bit.  We do a little
2082  // binary parsing here to fill in those missing bits, and then
2083  // reinterpret it all as a float.
2084  union {
2085    uint32_t integer;
2086    float fp;
2087  } fp_conv;
2088
2089  fp_conv.integer = Val;
2090  uint32_t b = fieldFromInstruction32(Val, 25, 1);
2091  fp_conv.integer |= b << 26;
2092  fp_conv.integer |= b << 27;
2093  fp_conv.integer |= b << 28;
2094  fp_conv.integer |= b << 29;
2095  fp_conv.integer |= (~b & 0x1) << 30;
2096
2097  Inst.addOperand(MCOperand::CreateFPImm(fp_conv.fp));
2098  return true;
2099}
2100
2101static bool DecodeThumbAddSpecialReg(llvm::MCInst &Inst, uint16_t Insn,
2102                                     uint64_t Address, const void *Decoder) {
2103  unsigned dst = fieldFromInstruction16(Insn, 8, 3);
2104  unsigned imm = fieldFromInstruction16(Insn, 0, 8);
2105
2106  if (!DecodetGPRRegisterClass(Inst, dst, Address, Decoder)) return false;
2107
2108  if (Inst.getOpcode() == ARM::tADR)
2109    Inst.addOperand(MCOperand::CreateReg(ARM::PC));
2110  else if (Inst.getOpcode() == ARM::tADDrSPi)
2111    Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2112  else
2113    return false;
2114
2115  Inst.addOperand(MCOperand::CreateImm(imm));
2116  return true;
2117}
2118
2119static bool DecodeThumbBROperand(llvm::MCInst &Inst, unsigned Val,
2120                                 uint64_t Address, const void *Decoder) {
2121  Inst.addOperand(MCOperand::CreateImm(SignExtend32<12>(Val << 1)));
2122  return true;
2123}
2124
2125static bool DecodeT2BROperand(llvm::MCInst &Inst, unsigned Val,
2126                                 uint64_t Address, const void *Decoder) {
2127  Inst.addOperand(MCOperand::CreateImm(SignExtend32<21>(Val)));
2128  return true;
2129}
2130
2131static bool DecodeThumbCmpBROperand(llvm::MCInst &Inst, unsigned Val,
2132                                 uint64_t Address, const void *Decoder) {
2133  Inst.addOperand(MCOperand::CreateImm(SignExtend32<7>(Val << 1)));
2134  return true;
2135}
2136
2137static bool DecodeThumbAddrModeRR(llvm::MCInst &Inst, unsigned Val,
2138                                 uint64_t Address, const void *Decoder) {
2139  unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2140  unsigned Rm = fieldFromInstruction32(Val, 3, 3);
2141
2142  if (!DecodetGPRRegisterClass(Inst, Rn, Address, Decoder) ||
2143      !DecodetGPRRegisterClass(Inst, Rm, Address, Decoder))
2144    return false;
2145
2146  return true;
2147}
2148
2149static bool DecodeThumbAddrModeIS(llvm::MCInst &Inst, unsigned Val,
2150                                  uint64_t Address, const void *Decoder) {
2151  unsigned Rn = fieldFromInstruction32(Val, 0, 3);
2152  unsigned imm = fieldFromInstruction32(Val, 3, 5);
2153
2154  if (!DecodetGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
2155  Inst.addOperand(MCOperand::CreateImm(imm));
2156
2157  return true;
2158}
2159
2160static bool DecodeThumbAddrModePC(llvm::MCInst &Inst, unsigned Val,
2161                                  uint64_t Address, const void *Decoder) {
2162  Inst.addOperand(MCOperand::CreateImm(Val << 2));
2163
2164  return true;
2165}
2166
2167static bool DecodeThumbAddrModeSP(llvm::MCInst &Inst, unsigned Val,
2168                                  uint64_t Address, const void *Decoder) {
2169  Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2170  Inst.addOperand(MCOperand::CreateImm(Val << 2));
2171
2172  return true;
2173}
2174
2175static bool DecodeT2AddrModeSOReg(llvm::MCInst &Inst, unsigned Val,
2176                                  uint64_t Address, const void *Decoder) {
2177  unsigned Rn = fieldFromInstruction32(Val, 6, 4);
2178  unsigned Rm = fieldFromInstruction32(Val, 2, 4);
2179  unsigned imm = fieldFromInstruction32(Val, 0, 2);
2180
2181  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder) ||
2182      !DecoderGPRRegisterClass(Inst, Rm, Address, Decoder))
2183    return false;
2184  Inst.addOperand(MCOperand::CreateImm(imm));
2185
2186  return true;
2187}
2188
2189static bool DecodeT2LoadShift(llvm::MCInst &Inst, unsigned Insn,
2190                              uint64_t Address, const void *Decoder) {
2191  if (Inst.getOpcode() != ARM::t2PLDs) {
2192    unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2193    if (!DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)) return false;
2194  }
2195
2196  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2197  if (Rn == 0xF) {
2198    switch (Inst.getOpcode()) {
2199      case ARM::t2LDRBs:
2200        Inst.setOpcode(ARM::t2LDRBpci);
2201        break;
2202      case ARM::t2LDRHs:
2203        Inst.setOpcode(ARM::t2LDRHpci);
2204        break;
2205      case ARM::t2LDRSHs:
2206        Inst.setOpcode(ARM::t2LDRSHpci);
2207        break;
2208      case ARM::t2LDRSBs:
2209        Inst.setOpcode(ARM::t2LDRSBpci);
2210        break;
2211      case ARM::t2PLDs:
2212        Inst.setOpcode(ARM::t2PLDi12);
2213        Inst.addOperand(MCOperand::CreateReg(ARM::PC));
2214        break;
2215      default:
2216        return false;
2217    }
2218
2219    int imm = fieldFromInstruction32(Insn, 0, 12);
2220    if (!fieldFromInstruction32(Insn, 23, 1)) imm *= -1;
2221    Inst.addOperand(MCOperand::CreateImm(imm));
2222
2223    return true;
2224  }
2225
2226  unsigned addrmode = fieldFromInstruction32(Insn, 4, 2);
2227  addrmode |= fieldFromInstruction32(Insn, 0, 4) << 2;
2228  addrmode |= fieldFromInstruction32(Insn, 16, 4) << 6;
2229  DecodeT2AddrModeSOReg(Inst, addrmode, Address, Decoder);
2230
2231  return true;
2232}
2233
2234static bool DecodeT2Imm8S4(llvm::MCInst &Inst, unsigned Val,
2235                           uint64_t Address, const void *Decoder) {
2236  int imm = Val & 0xFF;
2237  if (!(Val & 0x100)) imm *= -1;
2238  Inst.addOperand(MCOperand::CreateImm(imm << 2));
2239
2240  return true;
2241}
2242
2243static bool DecodeT2AddrModeImm8s4(llvm::MCInst &Inst, unsigned Val,
2244                                   uint64_t Address, const void *Decoder) {
2245  unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2246  unsigned imm = fieldFromInstruction32(Val, 0, 9);
2247
2248  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder) ||
2249      !DecodeT2Imm8S4(Inst, imm, Address, Decoder))
2250    return false;
2251
2252  return true;
2253}
2254
2255static bool DecodeT2Imm8(llvm::MCInst &Inst, unsigned Val,
2256                         uint64_t Address, const void *Decoder) {
2257  int imm = Val & 0xFF;
2258  if (!(Val & 0x100)) imm *= -1;
2259  Inst.addOperand(MCOperand::CreateImm(imm));
2260
2261  return true;
2262}
2263
2264
2265static bool DecodeT2AddrModeImm8(llvm::MCInst &Inst, unsigned Val,
2266                                 uint64_t Address, const void *Decoder) {
2267  unsigned Rn = fieldFromInstruction32(Val, 9, 4);
2268  unsigned imm = fieldFromInstruction32(Val, 0, 9);
2269
2270  // Some instructions always use an additive offset.
2271  switch (Inst.getOpcode()) {
2272    case ARM::t2LDRT:
2273    case ARM::t2LDRBT:
2274    case ARM::t2LDRHT:
2275    case ARM::t2LDRSBT:
2276    case ARM::t2LDRSHT:
2277      imm |= 0x100;
2278      break;
2279    default:
2280      break;
2281  }
2282
2283  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder) ||
2284      !DecodeT2Imm8(Inst, imm, Address, Decoder))
2285    return false;
2286
2287  return true;
2288}
2289
2290
2291static bool DecodeT2AddrModeImm12(llvm::MCInst &Inst, unsigned Val,
2292                                  uint64_t Address, const void *Decoder) {
2293  unsigned Rn = fieldFromInstruction32(Val, 13, 4);
2294  unsigned imm = fieldFromInstruction32(Val, 0, 12);
2295
2296  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
2297  Inst.addOperand(MCOperand::CreateImm(imm));
2298
2299  return true;
2300}
2301
2302
2303static bool DecodeThumbAddSPImm(llvm::MCInst &Inst, uint16_t Insn,
2304                                uint64_t Address, const void *Decoder) {
2305  unsigned imm = fieldFromInstruction16(Insn, 0, 7);
2306
2307  Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2308  Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2309  Inst.addOperand(MCOperand::CreateImm(imm));
2310
2311  return true;
2312}
2313
2314static bool DecodeThumbAddSPReg(llvm::MCInst &Inst, uint16_t Insn,
2315                                uint64_t Address, const void *Decoder) {
2316  if (Inst.getOpcode() == ARM::tADDrSP) {
2317    unsigned Rdm = fieldFromInstruction16(Insn, 0, 3);
2318    Rdm |= fieldFromInstruction16(Insn, 7, 1) << 3;
2319
2320    if (!DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)) return false;
2321    Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2322    if (!DecodeGPRRegisterClass(Inst, Rdm, Address, Decoder)) return false;
2323  } else if (Inst.getOpcode() == ARM::tADDspr) {
2324    unsigned Rm = fieldFromInstruction16(Insn, 3, 4);
2325
2326    Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2327    Inst.addOperand(MCOperand::CreateReg(ARM::SP));
2328    if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
2329  }
2330
2331  return true;
2332}
2333
2334static bool DecodeThumbCPS(llvm::MCInst &Inst, uint16_t Insn,
2335                           uint64_t Address, const void *Decoder) {
2336  unsigned imod = fieldFromInstruction16(Insn, 4, 1) | 0x2;
2337  unsigned flags = fieldFromInstruction16(Insn, 0, 3);
2338
2339  Inst.addOperand(MCOperand::CreateImm(imod));
2340  Inst.addOperand(MCOperand::CreateImm(flags));
2341
2342  return true;
2343}
2344
2345static bool DecodePostIdxReg(llvm::MCInst &Inst, unsigned Insn,
2346                             uint64_t Address, const void *Decoder) {
2347  unsigned Rm = fieldFromInstruction32(Insn, 0, 4);
2348  unsigned add = fieldFromInstruction32(Insn, 4, 1);
2349
2350  if (!DecodeGPRRegisterClass(Inst, Rm, Address, Decoder)) return false;
2351  Inst.addOperand(MCOperand::CreateImm(add));
2352
2353  return true;
2354}
2355
2356static bool DecodeThumbBLXOffset(llvm::MCInst &Inst, unsigned Val,
2357                                 uint64_t Address, const void *Decoder) {
2358  Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
2359  return true;
2360}
2361
2362static bool DecodeCoprocessor(llvm::MCInst &Inst, unsigned Val,
2363                              uint64_t Address, const void *Decoder) {
2364  if (Val == 0xA || Val == 0xB)
2365    return false;
2366
2367  Inst.addOperand(MCOperand::CreateImm(Val));
2368  return true;
2369}
2370
2371static bool DecodeThumbSRImm(llvm::MCInst &Inst, unsigned Val,
2372                             uint64_t Address, const void *Decoder) {
2373  if (Val == 0)
2374    Inst.addOperand(MCOperand::CreateImm(32));
2375  else
2376    Inst.addOperand(MCOperand::CreateImm(Val));
2377  return true;
2378}
2379
2380static bool DecodeThumb2BCCInstruction(llvm::MCInst &Inst, unsigned Insn,
2381                                       uint64_t Address, const void *Decoder) {
2382  unsigned pred = fieldFromInstruction32(Insn, 22, 4);
2383  if (pred == 0xE || pred == 0xF) {
2384    unsigned opc = fieldFromInstruction32(Insn, 4, 2);
2385    switch (opc) {
2386      default:
2387        return false;
2388      case 0:
2389        Inst.setOpcode(ARM::t2DSB);
2390        break;
2391      case 1:
2392        Inst.setOpcode(ARM::t2DMB);
2393        break;
2394      case 2:
2395        Inst.setOpcode(ARM::t2ISB);
2396        return true;
2397    }
2398
2399    unsigned imm = fieldFromInstruction32(Insn, 0, 4);
2400    return DecodeMemBarrierOption(Inst, imm, Address, Decoder);
2401  }
2402
2403  unsigned brtarget = fieldFromInstruction32(Insn, 0, 11) << 1;
2404  brtarget |= fieldFromInstruction32(Insn, 11, 1) << 19;
2405  brtarget |= fieldFromInstruction32(Insn, 13, 1) << 18;
2406  brtarget |= fieldFromInstruction32(Insn, 16, 6) << 12;
2407  brtarget |= fieldFromInstruction32(Insn, 26, 1) << 20;
2408
2409  if (!DecodeT2BROperand(Inst, brtarget, Address, Decoder) ||
2410      !DecodePredicateOperand(Inst, pred, Address, Decoder))
2411    return false;
2412
2413  return true;
2414}
2415
2416// Decode a shifted immediate operand.  These basically consist
2417// of an 8-bit value, and a 4-bit directive that specifies either
2418// a splat operation or a rotation.
2419static bool DecodeT2SOImm(llvm::MCInst &Inst, unsigned Val,
2420                          uint64_t Address, const void *Decoder) {
2421  unsigned ctrl = fieldFromInstruction32(Val, 10, 2);
2422  if (ctrl == 0) {
2423    unsigned byte = fieldFromInstruction32(Val, 8, 2);
2424    unsigned imm = fieldFromInstruction32(Val, 0, 8);
2425    switch (byte) {
2426      case 0:
2427        Inst.addOperand(MCOperand::CreateImm(imm));
2428        break;
2429      case 1:
2430        Inst.addOperand(MCOperand::CreateImm((imm << 16) | imm));
2431        break;
2432      case 2:
2433        Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 8)));
2434        break;
2435      case 3:
2436        Inst.addOperand(MCOperand::CreateImm((imm << 24) | (imm << 16) |
2437                                             (imm << 8)  |  imm));
2438        break;
2439    }
2440  } else {
2441    unsigned unrot = fieldFromInstruction32(Val, 0, 7) | 0x80;
2442    unsigned rot = fieldFromInstruction32(Val, 7, 5);
2443    unsigned imm = (unrot >> rot) | (unrot << ((32-rot)&31));
2444    Inst.addOperand(MCOperand::CreateImm(imm));
2445  }
2446
2447  return true;
2448}
2449
2450static bool DecodeThumbBCCTargetOperand(llvm::MCInst &Inst, unsigned Val,
2451                                        uint64_t Address, const void *Decoder){
2452  Inst.addOperand(MCOperand::CreateImm(Val << 1));
2453  return true;
2454}
2455
2456static bool DecodeThumbBLTargetOperand(llvm::MCInst &Inst, unsigned Val,
2457                                       uint64_t Address, const void *Decoder){
2458  Inst.addOperand(MCOperand::CreateImm(SignExtend32<22>(Val << 1)));
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 DecodeDoubleRegLoad(llvm::MCInst &Inst, unsigned Insn,
2490                                          uint64_t Address, const void *Decoder) {
2491  unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2492  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2493  unsigned pred = fieldFromInstruction32(Insn, 28, 4);
2494
2495  if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return false;
2496
2497  if (!DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)) return false;
2498  if (!DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)) return false;
2499  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
2500  if (!DecodePredicateOperand(Inst, pred, Address, Decoder)) return false;
2501
2502  return true;
2503}
2504
2505
2506static bool DecodeDoubleRegStore(llvm::MCInst &Inst, unsigned Insn,
2507                                          uint64_t Address, const void *Decoder) {
2508  unsigned Rd = fieldFromInstruction32(Insn, 12, 4);
2509  unsigned Rt = fieldFromInstruction32(Insn, 0, 4);
2510  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2511  unsigned pred = fieldFromInstruction32(Insn, 28, 4);
2512
2513  if (!DecoderGPRRegisterClass(Inst, Rd, Address, Decoder)) return false;
2514
2515  if ((Rt & 1) || Rt == 0xE || Rn == 0xF) return false;
2516  if (Rd == Rn || Rd == Rt || Rd == Rt+1) return false;
2517
2518  if (!DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)) return false;
2519  if (!DecodeGPRRegisterClass(Inst, Rt+1, Address, Decoder)) return false;
2520  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
2521  if (!DecodePredicateOperand(Inst, pred, Address, Decoder)) return false;
2522
2523  return true;
2524}
2525
2526static bool DecodeSTRPreImm(llvm::MCInst &Inst, unsigned Insn,
2527                            uint64_t Address, const void *Decoder) {
2528  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2529  unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2530  unsigned imm = fieldFromInstruction32(Insn, 0, 12);
2531  imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
2532  imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
2533  unsigned pred = fieldFromInstruction32(Insn, 28, 4);
2534
2535  if (Rn == 0xF || Rn == Rt) return false; // UNPREDICTABLE
2536
2537  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
2538  if (!DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)) return false;
2539  if (!DecodeAddrModeImm12Operand(Inst, imm, Address, Decoder)) return false;
2540  if (!DecodePredicateOperand(Inst, pred, Address, Decoder)) return false;
2541
2542  return true;
2543}
2544
2545static bool DecodeSTRPreReg(llvm::MCInst &Inst, unsigned Insn,
2546                            uint64_t Address, const void *Decoder) {
2547  unsigned Rn = fieldFromInstruction32(Insn, 16, 4);
2548  unsigned Rt = fieldFromInstruction32(Insn, 12, 4);
2549  unsigned imm = fieldFromInstruction32(Insn, 0, 12);
2550  imm |= fieldFromInstruction32(Insn, 16, 4) << 13;
2551  imm |= fieldFromInstruction32(Insn, 23, 1) << 12;
2552  unsigned pred = fieldFromInstruction32(Insn, 28, 4);
2553
2554  if (Rn == 0xF || Rn == Rt) return false; // UNPREDICTABLE
2555
2556  if (!DecodeGPRRegisterClass(Inst, Rn, Address, Decoder)) return false;
2557  if (!DecodeGPRRegisterClass(Inst, Rt, Address, Decoder)) return false;
2558  if (!DecodeSORegMemOperand(Inst, imm, Address, Decoder)) return false;
2559  if (!DecodePredicateOperand(Inst, pred, Address, Decoder)) return false;
2560
2561  return true;
2562}
2563