1/*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "disassembler_arm.h"
18
19#include <inttypes.h>
20
21#include <ostream>
22#include <sstream>
23
24#include "arch/arm/registers_arm.h"
25#include "base/bit_utils.h"
26#include "base/logging.h"
27#include "base/stringprintf.h"
28#include "thread.h"
29
30namespace art {
31namespace arm {
32
33size_t DisassemblerArm::Dump(std::ostream& os, const uint8_t* begin) {
34  if ((reinterpret_cast<intptr_t>(begin) & 1) == 0) {
35    DumpArm(os, begin);
36    return 4;
37  } else {
38    // remove thumb specifier bits
39    begin = reinterpret_cast<const uint8_t*>(reinterpret_cast<uintptr_t>(begin) & ~1);
40    return DumpThumb16(os, begin);
41  }
42}
43
44void DisassemblerArm::Dump(std::ostream& os, const uint8_t* begin, const uint8_t* end) {
45  if ((reinterpret_cast<intptr_t>(begin) & 1) == 0) {
46    for (const uint8_t* cur = begin; cur < end; cur += 4) {
47      DumpArm(os, cur);
48    }
49  } else {
50    // remove thumb specifier bits
51    begin = reinterpret_cast<const uint8_t*>(reinterpret_cast<uintptr_t>(begin) & ~1);
52    end = reinterpret_cast<const uint8_t*>(reinterpret_cast<uintptr_t>(end) & ~1);
53    for (const uint8_t* cur = begin; cur < end;) {
54      cur += DumpThumb16(os, cur);
55    }
56  }
57}
58
59static const char* kConditionCodeNames[] = {
60  "eq",  // 0000 - equal
61  "ne",  // 0001 - not-equal
62  "cs",  // 0010 - carry-set, greater than, equal or unordered
63  "cc",  // 0011 - carry-clear, less than
64  "mi",  // 0100 - minus, negative
65  "pl",  // 0101 - plus, positive or zero
66  "vs",  // 0110 - overflow
67  "vc",  // 0111 - no overflow
68  "hi",  // 1000 - unsigned higher
69  "ls",  // 1001 - unsigned lower or same
70  "ge",  // 1010 - signed greater than or equal
71  "lt",  // 1011 - signed less than
72  "gt",  // 1100 - signed greater than
73  "le",  // 1101 - signed less than or equal
74  "",    // 1110 - always
75  "nv",  // 1111 - never (mostly obsolete, but might be a clue that we're mistranslating)
76};
77
78void DisassemblerArm::DumpCond(std::ostream& os, uint32_t cond) {
79  if (cond < 15) {
80    os << kConditionCodeNames[cond];
81  } else {
82    os << "Unexpected condition: " << cond;
83  }
84}
85
86void DisassemblerArm::DumpMemoryDomain(std::ostream& os, uint32_t domain) {
87  switch (domain) {
88    case 15U /* 0b1111 */: os << "sy"; break;
89    case 14U /* 0b1110 */: os << "st"; break;
90    case 11U /* 0b1011 */: os << "ish"; break;
91    case 10U /* 0b1010 */: os << "ishst"; break;
92    case  7U /* 0b0111 */: os << "nsh"; break;
93    case  6U /* 0b0110 */: os << "nshst"; break;
94    case  3U /* 0b0011 */: os << "osh"; break;
95    case  2U /* 0b0010 */: os << "oshst"; break;
96  }
97}
98
99void DisassemblerArm::DumpBranchTarget(std::ostream& os, const uint8_t* instr_ptr, int32_t imm32) {
100  os << StringPrintf("%+d (", imm32) << FormatInstructionPointer(instr_ptr + imm32) << ")";
101}
102
103static uint32_t ReadU16(const uint8_t* ptr) {
104  return ptr[0] | (ptr[1] << 8);
105}
106
107static uint32_t ReadU32(const uint8_t* ptr) {
108  return ptr[0] | (ptr[1] << 8) | (ptr[2] << 16) | (ptr[3] << 24);
109}
110
111static const char* kDataProcessingOperations[] = {
112  "and", "eor", "sub", "rsb", "add", "adc", "sbc", "rsc",
113  "tst", "teq", "cmp", "cmn", "orr", "mov", "bic", "mvn",
114};
115
116static const char* kThumbDataProcessingOperations[] = {
117  "and", "eor", "lsl", "lsr", "asr", "adc", "sbc", "ror",
118  "tst", "rsb", "cmp", "cmn", "orr", "mul", "bic", "mvn",
119};
120
121static const char* const kThumb2ShiftOperations[] = {
122    "lsl", "lsr", "asr", "ror"
123};
124
125static const char* kThumbReverseOperations[] = {
126    "rev", "rev16", "rbit", "revsh"
127};
128
129struct ArmRegister {
130  explicit ArmRegister(uint32_t r_in) : r(r_in) { CHECK_LE(r_in, 15U); }
131  ArmRegister(uint32_t instruction, uint32_t at_bit) : r((instruction >> at_bit) & 0xf) {
132    CHECK_LE(r, 15U);
133  }
134  uint32_t r;
135};
136std::ostream& operator<<(std::ostream& os, const ArmRegister& r) {
137  if (r.r == 13) {
138    os << "sp";
139  } else if (r.r == 14) {
140    os << "lr";
141  } else if (r.r == 15) {
142    os << "pc";
143  } else {
144    os << "r" << r.r;
145  }
146  return os;
147}
148
149struct ThumbRegister : ArmRegister {
150  ThumbRegister(uint16_t instruction, uint16_t at_bit) : ArmRegister((instruction >> at_bit) & 0x7) {}
151};
152
153struct RmLslImm2 {
154  explicit RmLslImm2(uint32_t instr) : imm2((instr >> 4) & 0x3), rm(instr & 0xf) {}
155  uint32_t imm2;
156  ArmRegister rm;
157};
158std::ostream& operator<<(std::ostream& os, const RmLslImm2& r) {
159  os << r.rm;
160  if (r.imm2 != 0) {
161    os << ", lsl #" << r.imm2;
162  }
163  return os;
164}
165
166struct ShiftedImmediate {
167  explicit ShiftedImmediate(uint32_t instruction) {
168    uint32_t rotate = ((instruction >> 8) & 0xf);
169    uint32_t imm = (instruction & 0xff);
170    value = (imm >> (2 * rotate)) | (imm << (32 - (2 * rotate)));
171  }
172  uint32_t value;
173};
174std::ostream& operator<<(std::ostream& os, const ShiftedImmediate& rhs) {
175  os << "#" << rhs.value;
176  return os;
177}
178
179struct RegisterList {
180  explicit RegisterList(uint32_t instruction) : register_list(instruction & 0xffff) {}
181  uint32_t register_list;
182};
183std::ostream& operator<<(std::ostream& os, const RegisterList& rhs) {
184  if (rhs.register_list == 0) {
185    os << "<no register list?>";
186    return os;
187  }
188  os << "{";
189  bool first = true;
190  for (size_t i = 0; i < 16; i++) {
191    if ((rhs.register_list & (1 << i)) != 0) {
192      if (first) {
193        first = false;
194      } else {
195        os << ", ";
196      }
197      os << ArmRegister(i);
198    }
199  }
200  os << "}";
201  return os;
202}
203
204struct FpRegister {
205  FpRegister(uint32_t instr, uint16_t at_bit, uint16_t extra_at_bit) {
206    size = (instr >> 8) & 1;
207    uint32_t Vn = (instr >> at_bit) & 0xF;
208    uint32_t N = (instr >> extra_at_bit) & 1;
209    r = (size != 0 ? ((N << 4) | Vn) : ((Vn << 1) | N));
210  }
211  FpRegister(uint32_t instr, uint16_t at_bit, uint16_t extra_at_bit, uint32_t forced_size) {
212    size = forced_size;
213    uint32_t Vn = (instr >> at_bit) & 0xF;
214    uint32_t N = (instr >> extra_at_bit) & 1;
215    r = (size != 0 ? ((N << 4) | Vn) : ((Vn << 1) | N));
216  }
217  FpRegister(const FpRegister& other, uint32_t offset)
218      : size(other.size), r(other.r + offset) {}
219
220  uint32_t size;  // 0 = f32, 1 = f64
221  uint32_t r;
222};
223std::ostream& operator<<(std::ostream& os, const FpRegister& rhs) {
224  return os << ((rhs.size != 0) ? "d" : "s") << rhs.r;
225}
226
227struct FpRegisterRange {
228  explicit FpRegisterRange(uint32_t instr)
229      : first(instr, 12, 22), imm8(instr & 0xFF) {}
230  FpRegister first;
231  uint32_t imm8;
232};
233std::ostream& operator<<(std::ostream& os, const FpRegisterRange& rhs) {
234  os << "{" << rhs.first;
235  int count = (rhs.first.size != 0 ? ((rhs.imm8 + 1u) >> 1) : rhs.imm8);
236  if (count > 1) {
237    os << "-" << FpRegister(rhs.first, count - 1);
238  }
239  if (rhs.imm8 == 0) {
240    os << " (EMPTY)";
241  } else if (rhs.first.size != 0 && (rhs.imm8 & 1) != 0) {
242    os << rhs.first << " (HALF)";
243  }
244  os << "}";
245  return os;
246}
247
248void DisassemblerArm::DumpArm(std::ostream& os, const uint8_t* instr_ptr) {
249  uint32_t instruction = ReadU32(instr_ptr);
250  uint32_t cond = (instruction >> 28) & 0xf;
251  uint32_t op1 = (instruction >> 25) & 0x7;
252  std::string opcode;
253  std::string suffixes;
254  std::ostringstream args;
255  switch (op1) {
256    case 0:
257    case 1:  // Data processing instructions.
258      {
259        if ((instruction & 0x0ff000f0) == 0x01200070) {  // BKPT
260          opcode = "bkpt";
261          uint32_t imm12 = (instruction >> 8) & 0xfff;
262          uint32_t imm4 = (instruction & 0xf);
263          args << '#' << ((imm12 << 4) | imm4);
264          break;
265        }
266        if ((instruction & 0x0fffffd0) == 0x012fff10) {  // BX and BLX (register)
267          opcode = (((instruction >> 5) & 1) ? "blx" : "bx");
268          args << ArmRegister(instruction & 0xf);
269          break;
270        }
271        bool i = (instruction & (1 << 25)) != 0;
272        bool s = (instruction & (1 << 20)) != 0;
273        uint32_t op = (instruction >> 21) & 0xf;
274        opcode = kDataProcessingOperations[op];
275        bool implicit_s = ((op & ~3) == 8);  // TST, TEQ, CMP, and CMN.
276        bool is_mov = op == 13U /* 0b1101 */ || op == 15U /* 0b1111 */;
277        if (is_mov) {
278          // Show only Rd and Rm.
279          if (s) {
280             suffixes += 's';
281           }
282           args << ArmRegister(instruction, 12) << ", ";
283           if (i) {
284              args << ShiftedImmediate(instruction);
285            } else {
286              // TODO: Shifted register.
287              args << ArmRegister(instruction, 16) << ", " << ArmRegister(instruction, 0);
288            }
289        } else {
290          if (implicit_s) {
291            // Rd is unused (and not shown), and we don't show the 's' suffix either.
292          } else {
293            if (s) {
294              suffixes += 's';
295            }
296            args << ArmRegister(instruction, 12) << ", ";
297          }
298          if (i) {
299            args << ArmRegister(instruction, 16) << ", " << ShiftedImmediate(instruction);
300          } else {
301            // TODO: Shifted register.
302            args << ArmRegister(instruction, 16) << ", " << ArmRegister(instruction, 0);
303          }
304        }
305      }
306      break;
307    case 2:  // Load/store word and unsigned byte.
308      {
309        bool p = (instruction & (1 << 24)) != 0;
310        bool b = (instruction & (1 << 22)) != 0;
311        bool w = (instruction & (1 << 21)) != 0;
312        bool l = (instruction & (1 << 20)) != 0;
313        opcode = StringPrintf("%s%s", (l ? "ldr" : "str"), (b ? "b" : ""));
314        args << ArmRegister(instruction, 12) << ", ";
315        ArmRegister rn(instruction, 16);
316        if (rn.r == 0xf) {
317          UNIMPLEMENTED(FATAL) << "literals";
318        } else {
319          bool wback = !p || w;
320          uint32_t offset = (instruction & 0xfff);
321          if (p && !wback) {
322            args << "[" << rn << ", #" << offset << "]";
323          } else if (p && wback) {
324            args << "[" << rn << ", #" << offset << "]!";
325          } else if (!p && wback) {
326            args << "[" << rn << "], #" << offset;
327          } else {
328            LOG(FATAL) << p << " " << w;
329          }
330          if (rn.r == 9) {
331            args << "  ; ";
332            Thread::DumpThreadOffset<4>(args, offset);
333          }
334        }
335      }
336      break;
337    case 4:  // Load/store multiple.
338      {
339        bool p = (instruction & (1 << 24)) != 0;
340        bool u = (instruction & (1 << 23)) != 0;
341        bool w = (instruction & (1 << 21)) != 0;
342        bool l = (instruction & (1 << 20)) != 0;
343        opcode = StringPrintf("%s%c%c", (l ? "ldm" : "stm"), (u ? 'i' : 'd'), (p ? 'b' : 'a'));
344        args << ArmRegister(instruction, 16) << (w ? "!" : "") << ", " << RegisterList(instruction);
345      }
346      break;
347    case 5:  // Branch/branch with link.
348      {
349        bool bl = (instruction & (1 << 24)) != 0;
350        opcode = (bl ? "bl" : "b");
351        int32_t imm26 = (instruction & 0xffffff) << 2;
352        int32_t imm32 = (imm26 << 6) >> 6;  // Sign extend.
353        DumpBranchTarget(args, instr_ptr + 8, imm32);
354      }
355      break;
356    default:
357      opcode = "???";
358      break;
359    }
360    opcode += kConditionCodeNames[cond];
361    opcode += suffixes;
362    // TODO: a more complete ARM disassembler could generate wider opcodes.
363    os << FormatInstructionPointer(instr_ptr)
364       << StringPrintf(": %08x\t%-7s ", instruction, opcode.c_str())
365       << args.str() << '\n';
366}
367
368int32_t ThumbExpand(int32_t imm12) {
369  if ((imm12 & 0xC00) == 0) {
370    switch ((imm12 >> 8) & 3) {
371      case 0:
372        return imm12 & 0xFF;
373      case 1:
374        return ((imm12 & 0xFF) << 16) | (imm12 & 0xFF);
375      case 2:
376        return ((imm12 & 0xFF) << 24) | ((imm12 & 0xFF) << 8);
377      default:  // 3
378        return ((imm12 & 0xFF) << 24) | ((imm12 & 0xFF) << 16) | ((imm12 & 0xFF) << 8) |
379            (imm12 & 0xFF);
380    }
381  } else {
382    uint32_t val = 0x80 | (imm12 & 0x7F);
383    int32_t rotate = (imm12 >> 7) & 0x1F;
384    return (val >> rotate) | (val << (32 - rotate));
385  }
386}
387
388uint32_t VFPExpand32(uint32_t imm8) {
389  CHECK_EQ(imm8 & 0xffu, imm8);
390  uint32_t bit_a = (imm8 >> 7) & 1;
391  uint32_t bit_b = (imm8 >> 6) & 1;
392  uint32_t slice = imm8 & 0x3f;
393  return (bit_a << 31) | ((1 << 30) - (bit_b << 25)) | (slice << 19);
394}
395
396static uint64_t VFPExpand64(uint32_t imm8) {
397  CHECK_EQ(imm8 & 0xffu, imm8);
398  uint64_t bit_a = (imm8 >> 7) & 1;
399  uint64_t bit_b = (imm8 >> 6) & 1;
400  uint64_t slice = imm8 & 0x3f;
401  return (bit_a << 63) | ((UINT64_C(1) << 62) - (bit_b << 54)) | (slice << 48);
402}
403
404enum T2LitType {
405  kT2LitInvalid,
406  kT2LitUByte,
407  kT2LitSByte,
408  kT2LitUHalf,
409  kT2LitSHalf,
410  kT2LitUWord,
411  kT2LitSWord,
412  kT2LitHexWord,
413  kT2LitULong,
414  kT2LitSLong,
415  kT2LitHexLong,
416};
417std::ostream& operator<<(std::ostream& os, T2LitType type) {
418  return os << static_cast<int>(type);
419}
420
421void DumpThumb2Literal(std::ostream& args,
422                       const uint8_t* instr_ptr,
423                       const uintptr_t lo_adr,
424                       const uintptr_t hi_adr,
425                       uint32_t U,
426                       uint32_t imm32,
427                       T2LitType type) {
428  // Literal offsets (imm32) are not required to be aligned so we may need unaligned access.
429  typedef const int16_t unaligned_int16_t __attribute__ ((aligned (1)));
430  typedef const uint16_t unaligned_uint16_t __attribute__ ((aligned (1)));
431  typedef const int32_t unaligned_int32_t __attribute__ ((aligned (1)));
432  typedef const uint32_t unaligned_uint32_t __attribute__ ((aligned (1)));
433  typedef const int64_t unaligned_int64_t __attribute__ ((aligned (1)));
434  typedef const uint64_t unaligned_uint64_t __attribute__ ((aligned (1)));
435
436  // Get address of literal. Bail if not within expected buffer range to
437  // avoid trying to fetch invalid literals (we can encounter this when
438  // interpreting raw data as instructions).
439  uintptr_t pc = RoundDown(reinterpret_cast<intptr_t>(instr_ptr) + 4, 4);
440  uintptr_t lit_adr = U ? pc + imm32 : pc - imm32;
441  if (lit_adr < lo_adr || lit_adr >= hi_adr) {
442    args << "  ; (?)";
443    return;
444  }
445
446  args << "  ; ";
447  switch (type) {
448    case kT2LitUByte:
449      args << *reinterpret_cast<const uint8_t*>(lit_adr);
450      break;
451    case kT2LitSByte:
452      args << *reinterpret_cast<const int8_t*>(lit_adr);
453      break;
454    case kT2LitUHalf:
455      args << *reinterpret_cast<const unaligned_uint16_t*>(lit_adr);
456      break;
457    case kT2LitSHalf:
458      args << *reinterpret_cast<const unaligned_int16_t*>(lit_adr);
459      break;
460    case kT2LitUWord:
461      args << *reinterpret_cast<const unaligned_uint32_t*>(lit_adr);
462      break;
463    case kT2LitSWord:
464      args << *reinterpret_cast<const unaligned_int32_t*>(lit_adr);
465      break;
466    case kT2LitHexWord:
467      args << StringPrintf("0x%08x", *reinterpret_cast<const unaligned_uint32_t*>(lit_adr));
468      break;
469    case kT2LitULong:
470      args << *reinterpret_cast<const unaligned_uint64_t*>(lit_adr);
471      break;
472    case kT2LitSLong:
473      args << *reinterpret_cast<const unaligned_int64_t*>(lit_adr);
474      break;
475    case kT2LitHexLong:
476      args << StringPrintf("0x%" PRIx64, *reinterpret_cast<unaligned_int64_t*>(lit_adr));
477      break;
478    default:
479      LOG(FATAL) << "Invalid type: " << type;
480      break;
481  }
482}
483
484size_t DisassemblerArm::DumpThumb32(std::ostream& os, const uint8_t* instr_ptr) {
485  uint32_t instr = (ReadU16(instr_ptr) << 16) | ReadU16(instr_ptr + 2);
486  // |111|1 1|1000000|0000|1111110000000000|
487  // |5 3|2 1|0987654|3  0|5    0    5    0|
488  // |---|---|-------|----|----------------|
489  // |332|2 2|2222222|1111|1111110000000000|
490  // |1 9|8 7|6543210|9  6|5    0    5    0|
491  // |---|---|-------|----|----------------|
492  // |111|op1| op2   |    |                |
493  uint32_t op1 = (instr >> 27) & 3;
494  if (op1 == 0) {
495    return DumpThumb16(os, instr_ptr);
496  }
497
498  // Set valid address range of backing buffer.
499  const uintptr_t lo_adr = reinterpret_cast<intptr_t>(GetDisassemblerOptions()->base_address_);
500  const uintptr_t hi_adr = reinterpret_cast<intptr_t>(GetDisassemblerOptions()->end_address_);
501
502  uint32_t op2 = (instr >> 20) & 0x7F;
503  std::ostringstream opcode;
504  std::ostringstream args;
505  switch (op1) {
506    case 0:
507      break;
508    case 1:
509      if ((op2 & 0x64) == 0) {  // 00x x0xx
510        // |111|11|10|00|0|00|0000|1111110000000000|
511        // |5 3|21|09|87|6|54|3  0|5    0    5    0|
512        // |---|--|--|--|-|--|----|----------------|
513        // |332|22|22|22|2|22|1111|1111110000000000|
514        // |1 9|87|65|43|2|10|9  6|5    0    5    0|
515        // |---|--|--|--|-|--|----|----------------|
516        // |111|01|00|op|0|WL| Rn |                |
517        // |111|01| op2      |    |                |
518        // STM - 111 01 00-01-0-W0 nnnn rrrrrrrrrrrrrrrr
519        // LDM - 111 01 00-01-0-W1 nnnn rrrrrrrrrrrrrrrr
520        // PUSH- 111 01 00-01-0-10 1101 0M0rrrrrrrrrrrrr
521        // POP - 111 01 00-01-0-11 1101 PM0rrrrrrrrrrrrr
522        uint32_t op = (instr >> 23) & 3;
523        uint32_t W = (instr >> 21) & 1;
524        uint32_t L = (instr >> 20) & 1;
525        ArmRegister Rn(instr, 16);
526        if (op == 1 || op == 2) {
527          if (op == 1) {
528            if (L == 0) {
529              opcode << "stm";
530              args << Rn << (W == 0 ? "" : "!") << ", ";
531            } else {
532              if (Rn.r != 13) {
533                opcode << "ldm";
534                args << Rn << (W == 0 ? "" : "!") << ", ";
535              } else {
536                opcode << "pop";
537              }
538            }
539          } else {
540            if (L == 0) {
541              if (Rn.r != 13) {
542                opcode << "stmdb";
543                args << Rn << (W == 0 ? "" : "!") << ", ";
544              } else {
545                opcode << "push";
546              }
547            } else {
548              opcode << "ldmdb";
549              args << Rn << (W == 0 ? "" : "!") << ", ";
550            }
551          }
552          args << RegisterList(instr);
553        }
554      } else if ((op2 & 0x64) == 4) {  // 00x x1xx
555        uint32_t op3 = (instr >> 23) & 3;
556        uint32_t op4 = (instr >> 20) & 3;
557        // uint32_t op5 = (instr >> 4) & 0xF;
558        ArmRegister Rn(instr, 16);
559        ArmRegister Rt(instr, 12);
560        ArmRegister Rd(instr, 8);
561        uint32_t imm8 = instr & 0xFF;
562        if ((op3 & 2) == 2) {     // 1x
563          int W = (instr >> 21) & 1;
564          int U = (instr >> 23) & 1;
565          int P = (instr >> 24) & 1;
566
567          if ((op4 & 1) == 1) {
568            opcode << "ldrd";
569          } else {
570            opcode << "strd";
571          }
572          args << Rt << "," << Rd << ", [" << Rn;
573          const char *sign = U ? "+" : "-";
574          if (P == 0 && W == 1) {
575            args << "], #" << sign << (imm8 << 2);
576          } else {
577            args << ", #" << sign << (imm8 << 2) << "]";
578            if (W == 1) {
579              args << "!";
580            }
581          }
582        } else {                  // 0x
583          switch (op4) {
584            case 0:
585              if (op3 == 0) {   // op3 is 00, op4 is 00
586                opcode << "strex";
587                args << Rd << ", " << Rt << ", [" << Rn << ", #" << (imm8 << 2) << "]";
588                if (Rd.r == 13 || Rd.r == 15 || Rt.r == 13 || Rt.r == 15 || Rn.r == 15 ||
589                    Rd.r == Rn.r || Rd.r == Rt.r) {
590                  args << " (UNPREDICTABLE)";
591                }
592              } else {          // op3 is 01, op4 is 00
593                // this is one of strexb, strexh or strexd
594                int op5 = (instr >> 4) & 0xf;
595                switch (op5) {
596                  case 4:
597                  case 5:
598                    opcode << ((op5 == 4) ? "strexb" : "strexh");
599                    Rd = ArmRegister(instr, 0);
600                    args << Rd << ", " << Rt << ", [" << Rn << "]";
601                    if (Rd.r == 13 || Rd.r == 15 || Rt.r == 13 || Rt.r == 15 || Rn.r == 15 ||
602                        Rd.r == Rn.r || Rd.r == Rt.r || (instr & 0xf00) != 0xf00) {
603                      args << " (UNPREDICTABLE)";
604                    }
605                    break;
606                  case 7:
607                    opcode << "strexd";
608                    ArmRegister Rt2 = Rd;
609                    Rd = ArmRegister(instr, 0);
610                    args << Rd << ", " << Rt << ", " << Rt2 << ", [" << Rn << "]";
611                    if (Rd.r == 13 || Rd.r == 15 || Rt.r == 13 || Rt.r == 15 ||
612                        Rt2.r == 13 || Rt2.r == 15 || Rn.r == 15 ||
613                        Rd.r == Rn.r || Rd.r == Rt.r || Rd.r == Rt2.r) {
614                      args << " (UNPREDICTABLE)";
615                    }
616                    break;
617                }
618              }
619              break;
620            case 1:
621              if (op3 == 0) {   // op3 is 00, op4 is 01
622                opcode << "ldrex";
623                args << Rt << ", [" << Rn << ", #" << (imm8 << 2) << "]";
624                if (Rt.r == 13 || Rt.r == 15 || Rn.r == 15 || (instr & 0xf00) != 0xf00) {
625                  args << " (UNPREDICTABLE)";
626                }
627              } else {          // op3 is 01, op4 is 01
628                // this is one of strexb, strexh or strexd
629                int op5 = (instr >> 4) & 0xf;
630                switch (op5) {
631                  case 0:
632                    opcode << "tbb";
633                    break;
634                  case 1:
635                    opcode << "tbh";
636                    break;
637                  case 4:
638                  case 5:
639                    opcode << ((op5 == 4) ? "ldrexb" : "ldrexh");
640                    args << Rt << ", [" << Rn << "]";
641                    if (Rt.r == 13 || Rt.r == 15 || Rn.r == 15 || (instr & 0xf0f) != 0xf0f) {
642                      args << " (UNPREDICTABLE)";
643                    }
644                    break;
645                  case 7:
646                    opcode << "ldrexd";
647                    args << Rt << ", " << Rd /* Rt2 */ << ", [" << Rn << "]";
648                    if (Rt.r == 13 || Rt.r == 15 || Rd.r == 13 /* Rt2 */ || Rd.r == 15 /* Rt2 */ ||
649                        Rn.r == 15 || (instr & 0x00f) != 0x00f) {
650                      args << " (UNPREDICTABLE)";
651                    }
652                    break;
653                }
654              }
655              break;
656            case 2:     // op3 is 0x, op4 is 10
657            case 3:   // op3 is 0x, op4 is 11
658              if (op4 == 2) {
659                opcode << "strd";
660              } else {
661                opcode << "ldrd";
662              }
663              int W = (instr >> 21) & 1;
664              int U = (instr >> 23) & 1;
665              int P = (instr >> 24) & 1;
666
667              args << Rt << "," << Rd << ", [" << Rn;
668              const char *sign = U ? "+" : "-";
669              if (P == 0 && W == 1) {
670                args << "], #" << sign << imm8;
671              } else {
672                args << ", #" << sign << imm8 << "]";
673                if (W == 1) {
674                  args << "!";
675                }
676              }
677              break;
678          }
679        }
680
681      } else if ((op2 & 0x60) == 0x20) {  // 01x xxxx
682        // Data-processing (shifted register)
683        // |111|1110|0000|0|0000|1111|1100|00|00|0000|
684        // |5 3|2109|8765|4|3  0|5   |10 8|7 |5 |3  0|
685        // |---|----|----|-|----|----|----|--|--|----|
686        // |332|2222|2222|2|1111|1111|1100|00|00|0000|
687        // |1 9|8765|4321|0|9  6|5   |10 8|7 |5 |3  0|
688        // |---|----|----|-|----|----|----|--|--|----|
689        // |111|0101| op3|S| Rn |imm3| Rd |i2|ty| Rm |
690        uint32_t op3 = (instr >> 21) & 0xF;
691        uint32_t S = (instr >> 20) & 1;
692        uint32_t imm3 = ((instr >> 12) & 0x7);
693        uint32_t imm2 = ((instr >> 6) & 0x3);
694        uint32_t imm5 = ((imm3 << 2) | imm2);
695        uint32_t shift_type = ((instr >> 4) & 0x3);
696        ArmRegister Rd(instr, 8);
697        ArmRegister Rn(instr, 16);
698        ArmRegister Rm(instr, 0);
699        switch (op3) {
700          case 0x0:
701            if (Rd.r != 0xF) {
702              opcode << "and";
703            } else {
704              if (S != 1U) {
705                opcode << "UNKNOWN TST-" << S;
706                break;
707              }
708              opcode << "tst";
709              S = 0;  // don't print 's'
710            }
711            break;
712          case 0x1: opcode << "bic"; break;
713          case 0x2:
714            if (Rn.r != 0xF) {
715              opcode << "orr";
716            } else {
717              // TODO: use canonical form if there is a shift (lsl, ...).
718              opcode << "mov";
719            }
720            break;
721          case 0x3:
722            if (Rn.r != 0xF) {
723              opcode << "orn";
724            } else {
725              opcode << "mvn";
726            }
727            break;
728          case 0x4:
729            if (Rd.r != 0xF) {
730              opcode << "eor";
731            } else {
732              if (S != 1U) {
733                opcode << "UNKNOWN TEQ-" << S;
734                break;
735              }
736              opcode << "teq";
737              S = 0;  // don't print 's'
738            }
739            break;
740          case 0x6: opcode << "pkh"; break;
741          case 0x8:
742            if (Rd.r != 0xF) {
743              opcode << "add";
744            } else {
745              if (S != 1U) {
746                opcode << "UNKNOWN CMN-" << S;
747                break;
748              }
749              opcode << "cmn";
750              S = 0;  // don't print 's'
751            }
752            break;
753          case 0xA: opcode << "adc"; break;
754          case 0xB: opcode << "sbc"; break;
755          case 0xD:
756            if (Rd.r != 0xF) {
757              opcode << "sub";
758            } else {
759              if (S != 1U) {
760                opcode << "UNKNOWN CMP-" << S;
761                break;
762              }
763              opcode << "cmp";
764              S = 0;  // don't print 's'
765            }
766            break;
767          case 0xE: opcode << "rsb"; break;
768          default: opcode << "UNKNOWN DPSR-" << op3; break;
769        }
770
771        if (S == 1) {
772          opcode << "s";
773        }
774        opcode << ".w";
775
776        if (Rd.r != 0xF) {
777          args << Rd << ", ";
778        }
779        if (Rn.r != 0xF) {
780          args << Rn << ", ";
781        }
782        args << Rm;
783
784        // Shift operand.
785        bool noShift = (imm5 == 0 && shift_type != 0x3);
786        if (!noShift) {
787          args << ", ";
788          switch (shift_type) {
789            case 0x0: args << "lsl"; break;
790            case 0x1: args << "lsr"; break;
791            case 0x2: args << "asr"; break;
792            case 0x3:
793              if (imm5 == 0) {
794                args << "rrx";
795              } else {
796                args << "ror #" << imm5;
797              }
798              break;
799          }
800          if (shift_type != 0x3 /* rrx */) {
801            args << StringPrintf(" #%d", (0 != imm5 || 0 == shift_type) ? imm5 : 32);
802          }
803        }
804
805      } else if ((op2 & 0x40) == 0x40) {  // 1xx xxxx
806        // Co-processor instructions
807        // |111|1|11|000000|0000|1111|1100|000|0  |0000|
808        // |5 3|2|10|987654|3  0|54 2|10 8|7 5|4  |   0|
809        // |---|-|--|------|----|----|----|---|---|----|
810        // |332|2|22|222222|1111|1111|1100|000|0  |0000|
811        // |1 9|8|76|543210|9  6|54 2|10 8|7 5|4  |   0|
812        // |---|-|--|------|----|----|----|---|---|----|
813        // |111| |11| op3  | Rn |    |copr|   |op4|    |
814        uint32_t op3 = (instr >> 20) & 0x3F;
815        uint32_t coproc = (instr >> 8) & 0xF;
816        uint32_t op4 = (instr >> 4) & 0x1;
817
818        if (coproc == 0xA || coproc == 0xB) {   // 101x
819          if (op3 < 0x20 && (op3 & ~5) != 0) {     // 0xxxxx and not 000x0x
820            // Extension register load/store instructions
821            // |1111|110|00000|0000|1111|110|0|00000000|
822            // |5  2|1 9|87654|3  0|5  2|1 9|8|7      0|
823            // |----|---|-----|----|----|---|-|--------|
824            // |3322|222|22222|1111|1111|110|0|00000000|
825            // |1  8|7 5|4   0|9  6|5  2|1 9|8|7      0|
826            // |----|---|-----|----|----|---|-|--------|
827            // |1110|110|PUDWL| Rn | Vd |101|S|  imm8  |
828            uint32_t P = (instr >> 24) & 1;
829            uint32_t U = (instr >> 23) & 1;
830            uint32_t W = (instr >> 21) & 1;
831            if (P == U && W == 1) {
832              opcode << "UNDEFINED";
833            } else {
834              uint32_t L = (instr >> 20) & 1;
835              uint32_t S = (instr >> 8) & 1;
836              ArmRegister Rn(instr, 16);
837              if (P == 1 && W == 0) {  // VLDR
838                FpRegister d(instr, 12, 22);
839                uint32_t imm8 = instr & 0xFF;
840                opcode << (L == 1 ? "vldr" : "vstr");
841                args << d << ", [" << Rn << ", #" << ((U == 1) ? "" : "-")
842                     << (imm8 << 2) << "]";
843                if (Rn.r == 15 && U == 1) {
844                  DumpThumb2Literal(args, instr_ptr, lo_adr, hi_adr, U, imm8 << 2, kT2LitHexLong);
845                }
846              } else if (Rn.r == 13 && W == 1 && U == L) {  // VPUSH/VPOP
847                opcode << (L == 1 ? "vpop" : "vpush");
848                args << FpRegisterRange(instr);
849              } else {  // VLDM
850                opcode << (L == 1 ? "vldm" : "vstm");
851                args << Rn << ((W == 1) ? "!" : "") << ", "
852                     << FpRegisterRange(instr);
853              }
854              opcode << (S == 1 ? ".f64" : ".f32");
855            }
856          } else if ((op3 >> 1) == 2) {      // 00010x
857            if ((instr & 0xD0) == 0x10) {
858              // 64bit transfers between ARM core and extension registers.
859              uint32_t L = (instr >> 20) & 1;
860              uint32_t S = (instr >> 8) & 1;
861              ArmRegister Rt2(instr, 16);
862              ArmRegister Rt(instr, 12);
863              FpRegister m(instr, 0, 5);
864              opcode << "vmov" << (S ? ".f64" : ".f32");
865              if (L == 1) {
866                args << Rt << ", " << Rt2 << ", ";
867              }
868              if (S) {
869                args << m;
870              } else {
871                args << m << ", " << FpRegister(m, 1);
872              }
873              if (L == 0) {
874                args << ", " << Rt << ", " << Rt2;
875              }
876              if (Rt.r == 15 || Rt.r == 13 || Rt2.r == 15 || Rt2.r == 13 ||
877                  (S == 0 && m.r == 31) || (L == 1 && Rt.r == Rt2.r)) {
878                args << " (UNPREDICTABLE)";
879              }
880            }
881          } else if ((op3 >> 4) == 2 && op4 == 0) {     // 10xxxx, op = 0
882            // fp data processing
883            // VMLA, VMLS, VMUL, VNMUL, VADD, VSUB, VDIV, VMOV, ...
884            // |1111|1100|0|0|00|0000|1111|110|0|0|0|0|0|0000|
885            // |5  2|1  8|7|6|54|3  0|5  2|1 9|8|7|6|5|4|3  0|
886            // |----|----|-|-|--|----|----|---|-|-|-|-|-|----|
887            // |3322|2222|2|2|22|1111|1111|110|0|0|0|0|0|0000|
888            // |1  8|7  4|3|2|10|9  6|5  2|1 9|8|7|6|5|4|3  0|
889            // |----|----|-|-|--|----|----|---|-|-|-|-|-|----|
890            // |1110|1110|  op3 | Vn | Vd |101|S|N|Q|M|0| Vm |
891            // |1110|1110|0|D|00| Vn | Vd |101|S|N|0|M|0| Vm | VMLA
892            // |1110|1110|0|D|00| Vn | Vd |101|S|N|1|M|0| Vm | VMLS
893            // |1110|1110|0|D|10| Vn | Vd |101|S|N|0|M|0| Vm | VMUL
894            // |1110|1110|0|D|10| Vn | Vd |101|S|N|1|M|0| Vm | VNMUL
895            // |1110|1110|0|D|11| Vn | Vd |101|S|N|0|M|0| Vm | VADD
896            // |1110|1110|0|D|11| Vn | Vd |101|S|N|1|M|0| Vm | VSUB
897            // |1110|1110|1|D|00| Vn | Vd |101|S|N|0|M|0| Vm | VDIV
898            // |1110|1110|1|D|11| iH | Vd |101|S|0|0|0|0| iL | VMOV (imm)
899            // |1110|1110|1|D|11|op5 | Vd |101|S|.|1|M|0| Vm | ... (see below)
900            uint32_t S = (instr >> 8) & 1;
901            uint32_t Q = (instr >> 6) & 1;
902            FpRegister d(instr, 12, 22);
903            FpRegister n(instr, 16, 7);
904            FpRegister m(instr, 0, 5);
905            if ((op3 & 0xB) == 0) {  // 100x00
906              opcode << (Q == 0 ? "vmla" : "vmls") << (S != 0 ? ".f64" : ".f32");
907              args << d << ", " << n << ", " << m;
908            } else if ((op3 & 0xB) == 0x2) {  // 100x10
909              opcode << (Q == 0 ? "vmul" : "vnmul") << (S != 0 ? ".f64" : ".f32");
910              args << d << ", " << n << ", " << m;
911            } else if ((op3 & 0xB) == 0x3) {  // 100x11
912              opcode << (Q == 0 ? "vadd" : "vsub") << (S != 0 ? ".f64" : ".f32");
913              args << d << ", " << n << ", " << m;
914            } else if ((op3 & 0xB) == 0x8 && Q == 0) {  // 101x00, Q == 0
915              opcode << "vdiv" << (S != 0 ? ".f64" : ".f32");
916              args << d << ", " << n << ", " << m;
917            } else if ((op3 & 0xB) == 0xB && Q == 0) {  // 101x11, Q == 0
918              uint32_t imm8 = ((instr & 0xf0000u) >> 12) | (instr & 0xfu);
919              opcode << "vmov" << (S != 0 ? ".f64" : ".f32");
920              args << d << ", " << (S != 0 ? StringPrintf("0x%016" PRIx64, VFPExpand64(imm8))
921                                           : StringPrintf("0x%08x", VFPExpand32(imm8)));
922              if ((instr & 0xa0) != 0) {
923                args << " (UNPREDICTABLE)";
924              }
925            } else if ((op3 & 0xB) == 0xB && Q == 1) {  // 101x11, Q == 1
926              // VNEG, VSQRT, VCMP, VCMPE, VCVT (floating-point conversion)
927              // |1111|1100|0|0|00|0000|1111|110|0|0 |0|0|0|0000|
928              // |5  2|1  8|7|6|54|3  0|5  2|1 9|8|7 |6|5|4|3  0|
929              // |----|----|-|-|--|----|----|---|-|- |-|-|-|----|
930              // |3322|2222|2|2|22|1111|1111|110|0|0 |0|0|0|0000|
931              // |1  8|7  4|3|2|10|9  6|5  2|1 9|8|7 |6|5|4|3  0|
932              // |----|----|-|-|--|----|----|---|-|- |-|-|-|----|
933              // |1110|1110|1|D|11|0000| Vd |101|S|0 |1|M|0| Vm | VMOV (reg)
934              // |1110|1110|1|D|11|0000| Vd |101|S|1 |1|M|0| Vm | VABS
935              // |1110|1110|1|D|11|0001| Vd |101|S|0 |1|M|0| Vm | VNEG
936              // |1110|1110|1|D|11|0001| Vd |101|S|1 |1|M|0| Vm | VSQRT
937              // |1110|1110|1|D|11|0100| Vd |101|S|op|1|M|0| Vm | VCMP
938              // |1110|1110|1|D|11|0101| Vd |101|S|op|1|0|0|0000| VCMPE
939              // |1110|1110|1|D|11|op5 | Vd |101|S|op|1|M|0| Vm | VCVT
940              uint32_t op5 = (instr >> 16) & 0xF;
941              uint32_t op = (instr >> 7) & 1;
942              // Register types in VCVT instructions rely on the combination of op5 and S.
943              FpRegister Dd(instr, 12, 22, 1);
944              FpRegister Sd(instr, 12, 22, 0);
945              FpRegister Dm(instr, 0, 5, 1);
946              FpRegister Sm(instr, 0, 5, 0);
947              if (op5 == 0) {
948                opcode << (op == 0 ? "vmov" : "vabs") << (S != 0 ? ".f64" : ".f32");
949                args << d << ", " << m;
950              } else if (op5 == 1) {
951                opcode << (op != 0 ? "vsqrt" : "vneg") << (S != 0 ? ".f64" : ".f32");
952                args << d << ", " << m;
953              } else if (op5 == 4) {
954                opcode << "vcmp" << (S != 0 ? ".f64" : ".f32");
955                args << d << ", " << m;
956                if (op != 0) {
957                  args << " (quiet nan)";
958                }
959              } else if (op5 == 5) {
960                opcode << "vcmpe" << (S != 0 ? ".f64" : ".f32");
961                args << d << ", #0.0";
962                if (op != 0) {
963                  args << " (quiet nan)";
964                }
965                if ((instr & 0x2f) != 0) {
966                  args << " (UNPREDICTABLE)";
967                }
968              } else if (op5 == 0xD) {
969                if (S == 1) {
970                  // vcvt{r}.s32.f64
971                  opcode << "vcvt" << (op == 0 ? "r" : "") << ".s32.f64";
972                  args << Sd << ", " << Dm;
973                } else {
974                  // vcvt{r}.s32.f32
975                  opcode << "vcvt" << (op == 0 ? "r" : "") << ".s32.f32";
976                  args << Sd << ", " << Sm;
977                }
978              } else if (op5 == 0xC) {
979                if (S == 1) {
980                  // vcvt{r}.u32.f64
981                  opcode << "vcvt" << (op == 0 ? "r" : "") << ".u32.f64";
982                  args << Sd << ", " << Dm;
983                } else {
984                  // vcvt{r}.u32.f32
985                  opcode << "vcvt" << (op == 0 ? "r" : "") << ".u32.f32";
986                  args << Sd << ", " << Sm;
987                }
988              } else if (op5 == 0x8) {
989                if (S == 1) {
990                  // vcvt.f64.<Tm>
991                  opcode << "vcvt.f64." << (op == 0 ? "u" : "s") << "32";
992                  args << Dd << ", " << Sm;
993                } else {
994                  // vcvt.f32.<Tm>
995                  opcode << "vcvt.f32." << (op == 0 ? "u" : "s") << "32";
996                  args << Sd << ", " << Sm;
997                }
998              } else if (op5 == 0x7) {
999                if (op == 1) {
1000                  if (S == 1) {
1001                    // vcvt.f64.f32
1002                    opcode << "vcvt.f64.f32";
1003                    args << Dd << ", " << Sm;
1004                  } else {
1005                    // vcvt.f32.f64
1006                    opcode << "vcvt.f32.f64";
1007                    args << Sd << ", " << Dm;
1008                  }
1009                }
1010              } else if ((op5 & 0xa) == 0xa) {
1011                opcode << "vcvt";
1012                args << "[undecoded: floating <-> fixed]";
1013              }
1014            }
1015          } else if ((op3 >> 4) == 2 && op4 == 1) {     // 10xxxx, op = 1
1016            if (coproc == 10 && (op3 & 0xE) == 0) {
1017              // VMOV (between ARM core register and single-precision register)
1018              // |1111|1100|000|0 |0000|1111|1100|0|00|0|0000|
1019              // |5   |1  8|7 5|4 |3  0|5  2|1  8|7|65|4|3  0|
1020              // |----|----|---|- |----|----|----|-|--|-|----|
1021              // |3322|2222|222|2 |1111|1111|1100|0|00|0|0000|
1022              // |1  8|7  4|3 1|0 |9  6|5  2|1  8|7|65|4|3  0|
1023              // |----|----|---|- |----|----|----|-|--|-|----|
1024              // |1110|1110|000|op| Vn | Rt |1010|N|00|1|0000|
1025              uint32_t op = op3 & 1;
1026              ArmRegister Rt(instr, 12);
1027              FpRegister n(instr, 16, 7);
1028              opcode << "vmov.f32";
1029              if (op) {
1030                args << Rt << ", " << n;
1031              } else {
1032                args << n << ", " << Rt;
1033              }
1034              if (Rt.r == 13 || Rt.r == 15 || (instr & 0x6F) != 0) {
1035                args << " (UNPREDICTABLE)";
1036              }
1037            } else if (coproc == 10 && op3 == 0x2F) {
1038              // VMRS
1039              // |1111|11000000|0000|1111|1100|000|0|0000|
1040              // |5   |1      4|3  0|5  2|1  8|7 5|4|3  0|
1041              // |----|--------|----|----|----|---|-|----|
1042              // |3322|22222222|1111|1111|1100|000|0|0000|
1043              // |1  8|7      0|9  6|5  2|1  8|7 5|4|3  0|
1044              // |----|--------|----|----|----|---|-|----|
1045              // |1110|11101111|reg | Rt |1010|000|1|0000| - last 7 0s are (0)
1046              uint32_t spec_reg = (instr >> 16) & 0xF;
1047              ArmRegister Rt(instr, 12);
1048              opcode << "vmrs";
1049              if (spec_reg == 1) {
1050                if (Rt.r == 15) {
1051                  args << "APSR_nzcv, FPSCR";
1052                } else if (Rt.r == 13) {
1053                  args << Rt << ", FPSCR (UNPREDICTABLE)";
1054                } else {
1055                  args << Rt << ", FPSCR";
1056                }
1057              } else {
1058                args << "(PRIVILEGED)";
1059              }
1060            } else if (coproc == 11 && (op3 & 0x9) != 8) {
1061              // VMOV (ARM core register to scalar or vice versa; 8/16/32-bit)
1062            }
1063          }
1064        }
1065      }
1066      break;
1067    case 2:
1068      if ((instr & 0x8000) == 0 && (op2 & 0x20) == 0) {
1069        // Data-processing (modified immediate)
1070        // |111|11|10|0000|0|0000|1|111|1100|00000000|
1071        // |5 3|21|09|8765|4|3  0|5|4 2|10 8|7 5    0|
1072        // |---|--|--|----|-|----|-|---|----|--------|
1073        // |332|22|22|2222|2|1111|1|111|1100|00000000|
1074        // |1 9|87|65|4321|0|9  6|5|4 2|10 8|7 5    0|
1075        // |---|--|--|----|-|----|-|---|----|--------|
1076        // |111|10|i0| op3|S| Rn |0|iii| Rd |iiiiiiii|
1077        //  111 10 x0 xxxx x xxxx opxxx xxxx xxxxxxxx
1078        uint32_t i = (instr >> 26) & 1;
1079        uint32_t op3 = (instr >> 21) & 0xF;
1080        uint32_t S = (instr >> 20) & 1;
1081        ArmRegister Rn(instr, 16);
1082        uint32_t imm3 = (instr >> 12) & 7;
1083        ArmRegister Rd(instr, 8);
1084        uint32_t imm8 = instr & 0xFF;
1085        int32_t imm32 = (i << 11) | (imm3 << 8) | imm8;
1086        if (Rn.r == 0xF && (op3 == 0x2 || op3 == 0x3)) {
1087          if (op3 == 0x2) {
1088            opcode << "mov";
1089            if (S == 1) {
1090              opcode << "s";
1091            }
1092            opcode << ".w";
1093          } else {
1094            opcode << "mvn";
1095            if (S == 1) {
1096              opcode << "s";
1097            }
1098          }
1099          args << Rd << ", #" << ThumbExpand(imm32);
1100        } else if (Rd.r == 0xF && S == 1 &&
1101                   (op3 == 0x0 || op3 == 0x4 || op3 == 0x8 || op3 == 0xD)) {
1102          if (op3 == 0x0) {
1103            opcode << "tst";
1104          } else if (op3 == 0x4) {
1105            opcode << "teq";
1106          } else if (op3 == 0x8) {
1107            opcode << "cmn.w";
1108          } else {
1109            opcode << "cmp.w";
1110          }
1111          args << Rn << ", #" << ThumbExpand(imm32);
1112        } else {
1113          switch (op3) {
1114            case 0x0: opcode << "and"; break;
1115            case 0x1: opcode << "bic"; break;
1116            case 0x2: opcode << "orr"; break;
1117            case 0x3: opcode << "orn"; break;
1118            case 0x4: opcode << "eor"; break;
1119            case 0x8: opcode << "add"; break;
1120            case 0xA: opcode << "adc"; break;
1121            case 0xB: opcode << "sbc"; break;
1122            case 0xD: opcode << "sub"; break;
1123            case 0xE: opcode << "rsb"; break;
1124            default: opcode << "UNKNOWN DPMI-" << op3; break;
1125          }
1126          if (S == 1) {
1127            opcode << "s";
1128          }
1129          args << Rd << ", " << Rn << ", #" << ThumbExpand(imm32);
1130        }
1131      } else if ((instr & 0x8000) == 0 && (op2 & 0x20) != 0) {
1132        // Data-processing (plain binary immediate)
1133        // |111|11|10|00000|0000|1|111110000000000|
1134        // |5 3|21|09|87654|3  0|5|4   0    5    0|
1135        // |---|--|--|-----|----|-|---------------|
1136        // |332|22|22|22222|1111|1|111110000000000|
1137        // |1 9|87|65|43210|9  6|5|4   0    5    0|
1138        // |---|--|--|-----|----|-|---------------|
1139        // |111|10|x1| op3 | Rn |0|xxxxxxxxxxxxxxx|
1140        uint32_t op3 = (instr >> 20) & 0x1F;
1141        switch (op3) {
1142          case 0x00: case 0x0A: {
1143            // ADD/SUB.W Rd, Rn #imm12 - 111 10 i1 0101 0 nnnn 0 iii dddd iiiiiiii
1144            ArmRegister Rd(instr, 8);
1145            ArmRegister Rn(instr, 16);
1146            uint32_t i = (instr >> 26) & 1;
1147            uint32_t imm3 = (instr >> 12) & 0x7;
1148            uint32_t imm8 = instr & 0xFF;
1149            uint32_t imm12 = (i << 11) | (imm3 << 8) | imm8;
1150            if (Rn.r != 0xF) {
1151              opcode << (op3 == 0 ? "addw" : "subw");
1152              args << Rd << ", " << Rn << ", #" << imm12;
1153            } else {
1154              opcode << "adr";
1155              args << Rd << ", ";
1156              DumpBranchTarget(args, instr_ptr + 4, (op3 == 0) ? imm12 : -imm12);
1157            }
1158            break;
1159          }
1160          case 0x04: case 0x0C: {
1161            // MOVW/T Rd, #imm16     - 111 10 i0 0010 0 iiii 0 iii dddd iiiiiiii
1162            ArmRegister Rd(instr, 8);
1163            uint32_t i = (instr >> 26) & 1;
1164            uint32_t imm3 = (instr >> 12) & 0x7;
1165            uint32_t imm8 = instr & 0xFF;
1166            uint32_t Rn = (instr >> 16) & 0xF;
1167            uint32_t imm16 = (Rn << 12) | (i << 11) | (imm3 << 8) | imm8;
1168            opcode << (op3 == 0x04 ? "movw" : "movt");
1169            args << Rd << ", #" << imm16;
1170            break;
1171          }
1172          case 0x16: case 0x14: case 0x1C: {
1173            // BFI Rd, Rn, #lsb, #width - 111 10 0 11 011 0 nnnn 0 iii dddd ii 0 iiiii
1174            // SBFX Rd, Rn, #lsb, #width - 111 10 0 11 010 0 nnnn 0 iii dddd ii 0 iiiii
1175            // UBFX Rd, Rn, #lsb, #width - 111 10 0 11 110 0 nnnn 0 iii dddd ii 0 iiiii
1176            ArmRegister Rd(instr, 8);
1177            ArmRegister Rn(instr, 16);
1178            uint32_t msb = instr & 0x1F;
1179            uint32_t imm2 = (instr >> 6) & 0x3;
1180            uint32_t imm3 = (instr >> 12) & 0x7;
1181            uint32_t lsb = (imm3 << 2) | imm2;
1182            uint32_t width = msb - lsb + 1;
1183            if (op3 == 0x16) {
1184              if (Rn.r != 0xF) {
1185                opcode << "bfi";
1186                args << Rd << ", " << Rn << ", #" << lsb << ", #" << width;
1187              } else {
1188                opcode << "bfc";
1189                args << Rd << ", #" << lsb << ", #" << width;
1190              }
1191            } else {
1192              opcode << ((op3 & 0x8) != 0u ? "ubfx" : "sbfx");
1193              args << Rd << ", " << Rn << ", #" << lsb << ", #" << width;
1194              if (Rd.r == 13 || Rd.r == 15 || Rn.r == 13 || Rn.r == 15 ||
1195                  (instr & 0x04000020) != 0u) {
1196                args << " (UNPREDICTABLE)";
1197              }
1198            }
1199            break;
1200          }
1201          default:
1202            break;
1203        }
1204      } else {
1205        // Branches and miscellaneous control
1206        // |111|11|1000000|0000|1|111|1100|00000000|
1207        // |5 3|21|0987654|3  0|5|4 2|10 8|7 5    0|
1208        // |---|--|-------|----|-|---|----|--------|
1209        // |332|22|2222222|1111|1|111|1100|00000000|
1210        // |1 9|87|6543210|9  6|5|4 2|10 8|7 5    0|
1211        // |---|--|-------|----|-|---|----|--------|
1212        // |111|10| op2   |    |1|op3|op4 |        |
1213
1214        uint32_t op3 = (instr >> 12) & 7;
1215        // uint32_t op4 = (instr >> 8) & 0xF;
1216        switch (op3) {
1217          case 0:
1218            if ((op2 & 0x38) != 0x38) {
1219              // Conditional branch
1220              // |111|11|1|0000|000000|1|1|1 |1|1 |10000000000|
1221              // |5 3|21|0|9876|543  0|5|4|3 |2|1 |0    5    0|
1222              // |---|--|-|----|------|-|-|--|-|--|-----------|
1223              // |332|22|2|2222|221111|1|1|1 |1|1 |10000000000|
1224              // |1 9|87|6|5432|109  6|5|4|3 |2|1 |0    5    0|
1225              // |---|--|-|----|------|-|-|--|-|--|-----------|
1226              // |111|10|S|cond| imm6 |1|0|J1|0|J2| imm11     |
1227              uint32_t S = (instr >> 26) & 1;
1228              uint32_t J2 = (instr >> 11) & 1;
1229              uint32_t J1 = (instr >> 13) & 1;
1230              uint32_t imm6 = (instr >> 16) & 0x3F;
1231              uint32_t imm11 = instr & 0x7FF;
1232              uint32_t cond = (instr >> 22) & 0xF;
1233              int32_t imm32 = (S << 20) |  (J2 << 19) | (J1 << 18) | (imm6 << 12) | (imm11 << 1);
1234              imm32 = (imm32 << 11) >> 11;  // sign extend 21bit immediate
1235              opcode << "b";
1236              DumpCond(opcode, cond);
1237              opcode << ".w";
1238              DumpBranchTarget(args, instr_ptr + 4, imm32);
1239            } else if (op2 == 0x3B) {
1240              // Miscellaneous control instructions
1241              uint32_t op5 = (instr >> 4) & 0xF;
1242              switch (op5) {
1243                case 4: opcode << "dsb"; DumpMemoryDomain(args, instr & 0xF); break;
1244                case 5: opcode << "dmb"; DumpMemoryDomain(args, instr & 0xF); break;
1245                case 6: opcode << "isb"; DumpMemoryDomain(args, instr & 0xF); break;
1246              }
1247            }
1248            break;
1249          case 2:
1250            if ((op2 & 0x38) == 0x38) {
1251              if (op2 == 0x7F) {
1252                opcode << "udf";
1253              }
1254              break;
1255            }
1256            FALLTHROUGH_INTENDED;  // Else deliberate fall-through to B.
1257          case 1: case 3: {
1258            // B
1259            // |111|11|1|0000|000000|11|1 |1|1 |10000000000|
1260            // |5 3|21|0|9876|543  0|54|3 |2|1 |0    5    0|
1261            // |---|--|-|----|------|--|--|-|--|-----------|
1262            // |332|22|2|2222|221111|11|1 |1|1 |10000000000|
1263            // |1 9|87|6|5  2|10   6|54|3 |2|1 |0    5    0|
1264            // |---|--|-|----|------|--|--|-|--|-----------|
1265            // |111|10|S|cond| imm6 |10|J1|0|J2| imm11     |
1266            // |111|10|S| imm10     |10|J1|1|J2| imm11     |
1267            uint32_t S = (instr >> 26) & 1;
1268            uint32_t cond = (instr >> 22) & 0xF;
1269            uint32_t J2 = (instr >> 11) & 1;
1270            uint32_t form = (instr >> 12) & 1;
1271            uint32_t J1 = (instr >> 13) & 1;
1272            uint32_t imm10 = (instr >> 16) & 0x3FF;
1273            uint32_t imm6  = (instr >> 16) & 0x3F;
1274            uint32_t imm11 = instr & 0x7FF;
1275            opcode << "b";
1276            int32_t imm32;
1277            if (form == 0) {
1278              DumpCond(opcode, cond);
1279              imm32 = (S << 20) | (J2 << 19) | (J1 << 18) | (imm6 << 12) | (imm11 << 1);
1280              imm32 = (imm32 << 11) >> 11;  // sign extend 21 bit immediate.
1281            } else {
1282              uint32_t I1 = (J1 ^ S) ^ 1;
1283              uint32_t I2 = (J2 ^ S) ^ 1;
1284              imm32 = (S << 24) | (I1 << 23) | (I2 << 22) | (imm10 << 12) | (imm11 << 1);
1285              imm32 = (imm32 << 7) >> 7;  // sign extend 25 bit immediate.
1286            }
1287            opcode << ".w";
1288            DumpBranchTarget(args, instr_ptr + 4, imm32);
1289            break;
1290          }
1291          case 4: case 6: case 5: case 7: {
1292            // BL, BLX (immediate)
1293            // |111|11|1|0000000000|11|1 |1|1 |10000000000|
1294            // |5 3|21|0|9876543  0|54|3 |2|1 |0    5    0|
1295            // |---|--|-|----------|--|--|-|--|-----------|
1296            // |332|22|2|2222221111|11|1 |1|1 |10000000000|
1297            // |1 9|87|6|5    0   6|54|3 |2|1 |0    5    0|
1298            // |---|--|-|----------|--|--|-|--|-----------|
1299            // |111|10|S| imm10    |11|J1|L|J2| imm11     |
1300            uint32_t S = (instr >> 26) & 1;
1301            uint32_t J2 = (instr >> 11) & 1;
1302            uint32_t L = (instr >> 12) & 1;
1303            uint32_t J1 = (instr >> 13) & 1;
1304            uint32_t imm10 = (instr >> 16) & 0x3FF;
1305            uint32_t imm11 = instr & 0x7FF;
1306            if (L == 0) {
1307              opcode << "bx";
1308            } else {
1309              opcode << "blx";
1310            }
1311            uint32_t I1 = ~(J1 ^ S);
1312            uint32_t I2 = ~(J2 ^ S);
1313            int32_t imm32 = (S << 24) | (I1 << 23) | (I2 << 22) | (imm10 << 12) | (imm11 << 1);
1314            imm32 = (imm32 << 8) >> 8;  // sign extend 24 bit immediate.
1315            DumpBranchTarget(args, instr_ptr + 4, imm32);
1316            break;
1317          }
1318        }
1319      }
1320      break;
1321    case 3:
1322      switch (op2) {
1323        case 0x07: case 0x0F: case 0x17: case 0x1F: {  // Explicitly UNDEFINED, A6.3.
1324          opcode << "UNDEFINED";
1325          break;
1326        }
1327        case 0x06: case 0x0E: {  // "Store single data item" undefined opcodes, A6.3.10.
1328          opcode << "UNDEFINED [store]";
1329          break;
1330        }
1331        case 0x15: case 0x1D: {  // "Load word" undefined opcodes, A6.3.7.
1332          opcode << "UNDEFINED [load]";
1333          break;
1334        }
1335        case 0x10: case 0x12: case 0x14: case 0x16: case 0x18: case 0x1A: case 0x1C: case 0x1E: {
1336          opcode << "UNKNOWN " << op2 << " [SIMD]";
1337          break;
1338        }
1339        case 0x01: case 0x00: case 0x09: case 0x08:   // {LD,ST}RB{,T}
1340        case 0x03: case 0x02: case 0x0B: case 0x0A:   // {LD,ST}RH{,T}
1341        case 0x05: case 0x04: case 0x0D: case 0x0C:   // {LD,ST}R{,T}
1342        case 0x11:            case 0x19:              // LDRSB{,T} (no signed store)
1343        case 0x13:            case 0x1B: {            // LDRSH{,T} (no signed store)
1344          // Load:
1345          // (Store is the same except that l==0 and always s==0 below.)
1346          //                       00s.whl (sign, word, half, load)
1347          // LDR{S}B  imm12: 11111|00s1001| Rn | Rt |imm12             (0x09)
1348          // LDR{S}B   imm8: 11111|00s0001| Rn | Rt |1PUW|imm8         (0x01)
1349          // LDR{S}BT  imm8: 11111|00s0001| Rn | Rt |1110|imm8         (0x01)
1350          // LDR{S}B    lit: 11111|00sU001|1111| Rt |imm12             (0x01/0x09)
1351          // LDR{S}B    reg: 11111|00s0001| Rn | Rt |000000|imm2| Rm   (0x01)
1352          // LDR{S}H  imm12: 11111|00s1011| Rn | Rt |imm12             (0x0B)
1353          // LDR{S}H   imm8: 11111|00s0011| Rn | Rt |1PUW|imm8         (0x03)
1354          // LDR{S}HT  imm8: 11111|00s0011| Rn | Rt |1110|imm8         (0x03)
1355          // LDR{S}H    lit: 11111|00sU011|1111| Rt |imm12             (0x03/0x0B)
1356          // LDR{S}H    reg: 11111|00s0011| Rn | Rt |000000|imm2| Rm   (0x03)
1357          // LDR      imm12: 11111|0001101| Rn | Rt |imm12             (0x0D)
1358          // LDR       imm8: 11111|0000101| Rn | Rt |1PUW|imm8         (0x05)
1359          // LDRT      imm8: 11111|0000101| Rn | Rt |1110|imm8         (0x05)
1360          // LDR        lit: 11111|000U101|1111| Rt |imm12             (0x05/0x0D)
1361          // LDR        reg: 11111|0000101| Rn | Rt |000000|imm2| Rm   (0x05)
1362          //
1363          // If Rt == 15, instead of load we have preload:
1364          // PLD{W}   imm12: 11111|00010W1| Rn |1111|imm12             (0x09/0x0B)
1365          // PLD{W}    imm8: 11111|00000W1| Rn |1111|1100|imm8         (0x01/0x03); -imm8
1366          // PLD        lit: 11111|000U001|1111|1111|imm12             (0x01/0x09)
1367          // PLD{W}     reg: 11111|00000W1| Rn |1111|000000|imm2| Rm   (0x01/0x03)
1368          // PLI      imm12: 11111|0011001| Rn |1111|imm12             (0x19)
1369          // PLI       imm8: 11111|0010001| Rn |1111|1100|imm8         (0x11); -imm8
1370          // PLI        lit: 11111|001U001|1111|1111|imm12             (0x01/0x09)
1371          // PLI        reg: 11111|0010001| Rn |1111|000000|imm2| Rm   (0x01/0x03)
1372
1373          bool is_load = HasBitSet(instr, 20);
1374          bool is_half = HasBitSet(instr, 21);  // W for PLD/PLDW.
1375          bool is_word = HasBitSet(instr, 22);
1376          bool is_signed = HasBitSet(instr, 24);
1377          ArmRegister Rn(instr, 16);
1378          ArmRegister Rt(instr, 12);
1379          uint32_t imm12 = instr & 0xFFF;
1380          uint32_t U = (instr >> 23) & 1;  // U for imm12
1381          uint32_t imm8 = instr & 0xFF;
1382          uint32_t op4 = (instr >> 8) & 0xF;  // 1PUW for imm8
1383          if (Rt.r == PC && is_load && !is_word) {
1384            // PLD, PLDW, PLI
1385            const char* pld_pli = (is_signed ? "pli" : "pld");
1386            const char* w = (is_half ? "w" : "");
1387            if (is_signed && !is_half) {
1388              opcode << "UNDEFINED [PLI+W]";
1389            } else if (Rn.r == PC || U != 0u) {
1390              opcode << pld_pli << w;
1391              args << "[" << Rn << ", #" << (U != 0u ? "" : "-") << imm12 << "]";
1392              if (Rn.r == PC && is_half) {
1393                args << " (UNPREDICTABLE)";
1394              }
1395            } else if ((instr & 0xFC0) == 0) {
1396              opcode << pld_pli << w;
1397              RmLslImm2 Rm(instr);
1398              args << "[" << Rn << ", " << Rm << "]";
1399            } else if (op4 == 0xC) {
1400              opcode << pld_pli << w;
1401              args << "[" << Rn << ", #-" << imm8 << "]";
1402            } else {
1403              opcode << "UNDEFINED [~" << pld_pli << "]";
1404            }
1405            break;
1406          }
1407          const char* ldr_str = is_load ? "ldr" : "str";
1408          const char* sign = is_signed ? "s" : "";
1409          const char* type = is_word ? "" : is_half ? "h" : "b";
1410          bool unpred = (Rt.r == SP && !is_word) || (Rt.r == PC && !is_load);
1411          if (Rn.r == PC && !is_load) {
1412            opcode << "UNDEFINED [STR-lit]";
1413            unpred = false;
1414          } else if (Rn.r == PC || U != 0u) {
1415            // Load/store with imm12 (load literal if Rn.r == PC; there's no store literal).
1416            opcode << ldr_str << sign << type << ".w";
1417            args << Rt << ", [" << Rn << ", #" << (U != 0u ? "" : "-") << imm12 << "]";
1418            if (Rn.r == TR && is_load) {
1419              args << "  ; ";
1420              Thread::DumpThreadOffset<4>(args, imm12);
1421            } else if (Rn.r == PC) {
1422              T2LitType lit_type[] = {
1423                  kT2LitUByte, kT2LitUHalf, kT2LitHexWord, kT2LitInvalid,
1424                  kT2LitUByte, kT2LitUHalf, kT2LitHexWord, kT2LitInvalid,
1425                  kT2LitSByte, kT2LitSHalf, kT2LitInvalid, kT2LitInvalid,
1426                  kT2LitSByte, kT2LitSHalf, kT2LitInvalid, kT2LitInvalid,
1427              };
1428              DCHECK_LT(op2 >> 1, arraysize(lit_type));
1429              DCHECK_NE(lit_type[op2 >> 1], kT2LitInvalid);
1430              DumpThumb2Literal(args, instr_ptr, lo_adr, hi_adr, U, imm12, lit_type[op2 >> 1]);
1431            }
1432          } else if ((instr & 0xFC0) == 0) {
1433            opcode << ldr_str << sign << type << ".w";
1434            RmLslImm2 Rm(instr);
1435            args << Rt << ", [" << Rn << ", " << Rm << "]";
1436            unpred = unpred || (Rm.rm.r == SP) || (Rm.rm.r == PC);
1437          } else if (is_word && Rn.r == SP && imm8 == 4 && op4 == (is_load ? 0xB : 0xD)) {
1438            opcode << (is_load ? "pop" : "push") << ".w";
1439            args << Rn;
1440            unpred = unpred || (Rn.r == SP);
1441          } else if ((op4 & 5) == 0) {
1442            opcode << "UNDEFINED [P = W = 0 for " << ldr_str << "]";
1443            unpred = false;
1444          } else {
1445            uint32_t P = (instr >> 10) & 1;
1446            U = (instr >> 9) & 1;
1447            uint32_t W = (instr >> 8) & 1;
1448            bool pre_index = (P != 0 && W == 1);
1449            bool post_index = (P == 0 && W == 1);
1450            const char* t = (P != 0 && U != 0 && W == 0) ? "t" : "";  // Unprivileged load/store?
1451            opcode << ldr_str << sign << type << t << ".w";
1452            args << Rt << ", [" << Rn << (post_index ? "]" : "") << ", #" << (U != 0 ? "" : "-")
1453                << imm8 << (post_index ? "" : "]") << (pre_index ? "!" : "");
1454            unpred = (W != 0 && Rn.r == Rt.r);
1455          }
1456          if (unpred) {
1457            args << " (UNPREDICTABLE)";
1458          }
1459          break;
1460        }
1461        case 0x29: {  // 0101001
1462          // |111|11|1000000|0000|1111|1100|00|0 0|0000|
1463          // |5 3|21|0     4|3  0|5  2|1  8|76|5 4|3  0|
1464          // |---|--|-------|----|----|----|--|---|----|
1465          // |332|22|2222222|1111|1111|1100|00|0 0|0000|
1466          // |1 9|87|6     0|9  6|5  2|1  8|76|5 4|3  0|
1467          // |---|--|-------|----|----|----|--|---|----|
1468          // |111|11|0101001| Rm |1111| Rd |11|op3| Rm |
1469          // REV   - 111 11 0101001 mmmm 1111 dddd 1000 mmmm
1470          // REV16 - 111 11 0101001 mmmm 1111 dddd 1001 mmmm
1471          // RBIT  - 111 11 0101001 mmmm 1111 dddd 1010 mmmm
1472          // REVSH - 111 11 0101001 mmmm 1111 dddd 1011 mmmm
1473          if ((instr & 0xf0c0) == 0xf080) {
1474            uint32_t op3 = (instr >> 4) & 3;
1475            opcode << kThumbReverseOperations[op3];
1476            ArmRegister Rm(instr, 0);
1477            ArmRegister Rd(instr, 8);
1478            args << Rd << ", " << Rm;
1479            ArmRegister Rm2(instr, 16);
1480            if (Rm.r != Rm2.r || Rm.r == 13 || Rm.r == 15 || Rd.r == 13 || Rd.r == 15) {
1481              args << " (UNPREDICTABLE)";
1482            }
1483          }  // else unknown instruction
1484          break;
1485        }
1486        case 0x2B: {  // 0101011
1487          //  CLZ - 111 11 0101011 mmmm 1111 dddd 1000 mmmm
1488          if ((instr & 0xf0f0) == 0xf080) {
1489            opcode << "clz";
1490            ArmRegister Rm(instr, 0);
1491            ArmRegister Rd(instr, 8);
1492            args << Rd << ", " << Rm;
1493            ArmRegister Rm2(instr, 16);
1494            if (Rm.r != Rm2.r || Rm.r == 13 || Rm.r == 15 || Rd.r == 13 || Rd.r == 15) {
1495              args << " (UNPREDICTABLE)";
1496            }
1497          }
1498          break;
1499        }
1500      default:      // more formats
1501        if ((op2 >> 4) == 2) {      // 010xxxx
1502          // data processing (register)
1503          if ((instr & 0x0080f0f0) == 0x0000f000) {
1504            // LSL, LSR, ASR, ROR
1505            uint32_t shift_op = (instr >> 21) & 3;
1506            uint32_t S = (instr >> 20) & 1;
1507            ArmRegister Rd(instr, 8);
1508            ArmRegister Rn(instr, 16);
1509            ArmRegister Rm(instr, 0);
1510            opcode << kThumb2ShiftOperations[shift_op] << (S != 0 ? "s" : "");
1511            args << Rd << ", " << Rn << ", " << Rm;
1512          }
1513        } else if ((op2 >> 3) == 6) {       // 0110xxx
1514          // Multiply, multiply accumulate, and absolute difference
1515          op1 = (instr >> 20) & 0x7;
1516          op2 = (instr >> 4) & 0x1;
1517          ArmRegister Ra(instr, 12);
1518          ArmRegister Rn(instr, 16);
1519          ArmRegister Rm(instr, 0);
1520          ArmRegister Rd(instr, 8);
1521          switch (op1) {
1522          case 0:
1523            if (op2 == 0) {
1524              if (Ra.r == 0xf) {
1525                opcode << "mul";
1526                args << Rd << ", " << Rn << ", " << Rm;
1527              } else {
1528                opcode << "mla";
1529                args << Rd << ", " << Rn << ", " << Rm << ", " << Ra;
1530              }
1531            } else {
1532              opcode << "mls";
1533              args << Rd << ", " << Rn << ", " << Rm << ", " << Ra;
1534            }
1535            break;
1536          case 1:
1537          case 2:
1538          case 3:
1539          case 4:
1540          case 5:
1541          case 6:
1542              break;        // do these sometime
1543          }
1544        } else if ((op2 >> 3) == 7) {       // 0111xxx
1545          // Long multiply, long multiply accumulate, and divide
1546          op1 = (instr >> 20) & 0x7;
1547          op2 = (instr >> 4) & 0xf;
1548          ArmRegister Rn(instr, 16);
1549          ArmRegister Rm(instr, 0);
1550          ArmRegister Rd(instr, 8);
1551          ArmRegister RdHi(instr, 8);
1552          ArmRegister RdLo(instr, 12);
1553          switch (op1) {
1554          case 0:
1555            opcode << "smull";
1556            args << RdLo << ", " << RdHi << ", " << Rn << ", " << Rm;
1557            break;
1558          case 1:
1559            opcode << "sdiv";
1560            args << Rd << ", " << Rn << ", " << Rm;
1561            break;
1562          case 2:
1563            opcode << "umull";
1564            args << RdLo << ", " << RdHi << ", " << Rn << ", " << Rm;
1565            break;
1566          case 3:
1567            opcode << "udiv";
1568            args << Rd << ", " << Rn << ", " << Rm;
1569            break;
1570          case 4:
1571          case 5:
1572          case 6:
1573            break;      // TODO: when we generate these...
1574          }
1575        }
1576      }
1577      break;
1578    default:
1579      break;
1580  }
1581
1582  // Apply any IT-block conditions to the opcode if necessary.
1583  if (!it_conditions_.empty()) {
1584    opcode << it_conditions_.back();
1585    it_conditions_.pop_back();
1586  }
1587  if (opcode.str().size() == 0) {
1588    opcode << "UNKNOWN " << op2;
1589  }
1590
1591  os << FormatInstructionPointer(instr_ptr)
1592     << StringPrintf(": %08x\t%-7s ", instr, opcode.str().c_str())
1593     << args.str() << '\n';
1594  return 4;
1595}  // NOLINT(readability/fn_size)
1596
1597size_t DisassemblerArm::DumpThumb16(std::ostream& os, const uint8_t* instr_ptr) {
1598  uint16_t instr = ReadU16(instr_ptr);
1599  bool is_32bit = ((instr & 0xF000) == 0xF000) || ((instr & 0xF800) == 0xE800);
1600  if (is_32bit) {
1601    return DumpThumb32(os, instr_ptr);
1602  } else {
1603    std::ostringstream opcode;
1604    std::ostringstream args;
1605    uint16_t opcode1 = instr >> 10;
1606    if (opcode1 < 0x10) {
1607      // shift (immediate), add, subtract, move, and compare
1608      uint16_t opcode2 = instr >> 9;
1609      switch (opcode2) {
1610        case 0x0: case 0x1: case 0x2: case 0x3: case 0x4: case 0x5: case 0x6: case 0x7:
1611        case 0x8: case 0x9: case 0xA: case 0xB: {
1612          // Logical shift left     - 00 000xx iii mmm ddd
1613          // Logical shift right    - 00 001xx iii mmm ddd
1614          // Arithmetic shift right - 00 010xx iii mmm ddd
1615          uint16_t imm5 = (instr >> 6) & 0x1F;
1616          ThumbRegister rm(instr, 3);
1617          ThumbRegister Rd(instr, 0);
1618          if (opcode2 <= 3) {
1619            opcode << "lsls";
1620          } else if (opcode2 <= 7) {
1621            opcode << "lsrs";
1622          } else {
1623            opcode << "asrs";
1624          }
1625          args << Rd << ", " << rm << ", #" << imm5;
1626          break;
1627        }
1628        case 0xC: case 0xD: case 0xE: case 0xF: {
1629          // Add register        - 00 01100 mmm nnn ddd
1630          // Sub register        - 00 01101 mmm nnn ddd
1631          // Add 3-bit immediate - 00 01110 iii nnn ddd
1632          // Sub 3-bit immediate - 00 01111 iii nnn ddd
1633          uint16_t imm3_or_Rm = (instr >> 6) & 7;
1634          ThumbRegister Rn(instr, 3);
1635          ThumbRegister Rd(instr, 0);
1636          if ((opcode2 & 2) != 0 && imm3_or_Rm == 0) {
1637            opcode << "mov";
1638          } else {
1639            if ((opcode2 & 1) == 0) {
1640              opcode << "adds";
1641            } else {
1642              opcode << "subs";
1643            }
1644          }
1645          args << Rd << ", " << Rn;
1646          if ((opcode2 & 2) == 0) {
1647            ArmRegister Rm(imm3_or_Rm);
1648            args << ", " << Rm;
1649          } else if (imm3_or_Rm != 0) {
1650            args << ", #" << imm3_or_Rm;
1651          }
1652          break;
1653        }
1654        case 0x10: case 0x11: case 0x12: case 0x13:
1655        case 0x14: case 0x15: case 0x16: case 0x17:
1656        case 0x18: case 0x19: case 0x1A: case 0x1B:
1657        case 0x1C: case 0x1D: case 0x1E: case 0x1F: {
1658          // MOVS Rd, #imm8 - 00100 ddd iiiiiiii
1659          // CMP  Rn, #imm8 - 00101 nnn iiiiiiii
1660          // ADDS Rn, #imm8 - 00110 nnn iiiiiiii
1661          // SUBS Rn, #imm8 - 00111 nnn iiiiiiii
1662          ThumbRegister Rn(instr, 8);
1663          uint16_t imm8 = instr & 0xFF;
1664          switch (opcode2 >> 2) {
1665            case 4: opcode << "movs"; break;
1666            case 5: opcode << "cmp"; break;
1667            case 6: opcode << "adds"; break;
1668            case 7: opcode << "subs"; break;
1669          }
1670          args << Rn << ", #" << imm8;
1671          break;
1672        }
1673        default:
1674          break;
1675      }
1676    } else if (opcode1 == 0x10) {
1677      // Data-processing
1678      uint16_t opcode2 = (instr >> 6) & 0xF;
1679      ThumbRegister rm(instr, 3);
1680      ThumbRegister rdn(instr, 0);
1681      opcode << kThumbDataProcessingOperations[opcode2];
1682      args << rdn << ", " << rm;
1683    } else if (opcode1 == 0x11) {
1684      // Special data instructions and branch and exchange
1685      uint16_t opcode2 = (instr >> 6) & 0x0F;
1686      switch (opcode2) {
1687        case 0x0: case 0x1: case 0x2: case 0x3: {
1688          // Add low registers  - 010001 0000 xxxxxx
1689          // Add high registers - 010001 0001/001x xxxxxx
1690          uint16_t DN = (instr >> 7) & 1;
1691          ArmRegister rm(instr, 3);
1692          uint16_t Rdn = instr & 7;
1693          ArmRegister DN_Rdn((DN << 3) | Rdn);
1694          opcode << "add";
1695          args << DN_Rdn << ", " << rm;
1696          break;
1697        }
1698        case 0x8: case 0x9: case 0xA: case 0xB: {
1699          // Move low registers  - 010001 1000 xxxxxx
1700          // Move high registers - 010001 1001/101x xxxxxx
1701          uint16_t DN = (instr >> 7) & 1;
1702          ArmRegister rm(instr, 3);
1703          uint16_t Rdn = instr & 7;
1704          ArmRegister DN_Rdn((DN << 3) | Rdn);
1705          opcode << "mov";
1706          args << DN_Rdn << ", " << rm;
1707          break;
1708        }
1709        case 0x5: case 0x6: case 0x7: {
1710          // Compare high registers - 010001 0101/011x xxxxxx
1711          uint16_t N = (instr >> 7) & 1;
1712          ArmRegister rm(instr, 3);
1713          uint16_t Rn = instr & 7;
1714          ArmRegister N_Rn((N << 3) | Rn);
1715          opcode << "cmp";
1716          args << N_Rn << ", " << rm;
1717          break;
1718        }
1719        case 0xC: case 0xD: case 0xE: case 0xF: {
1720          // Branch and exchange           - 010001 110x xxxxxx
1721          // Branch with link and exchange - 010001 111x xxxxxx
1722          ArmRegister rm(instr, 3);
1723          opcode << ((opcode2 & 0x2) == 0 ? "bx" : "blx");
1724          args << rm;
1725          break;
1726        }
1727        default:
1728          break;
1729      }
1730    } else if (opcode1 == 0x12 || opcode1 == 0x13) {  // 01001x
1731      const uintptr_t lo_adr = reinterpret_cast<intptr_t>(GetDisassemblerOptions()->base_address_);
1732      const uintptr_t hi_adr = reinterpret_cast<intptr_t>(GetDisassemblerOptions()->end_address_);
1733      ThumbRegister Rt(instr, 8);
1734      uint16_t imm8 = instr & 0xFF;
1735      opcode << "ldr";
1736      args << Rt << ", [pc, #" << (imm8 << 2) << "]";
1737      DumpThumb2Literal(args, instr_ptr, lo_adr, hi_adr, /*U*/ 1u, imm8 << 2, kT2LitHexWord);
1738    } else if ((opcode1 >= 0x14 && opcode1 <= 0x17) ||  // 0101xx
1739               (opcode1 >= 0x18 && opcode1 <= 0x1f) ||  // 011xxx
1740               (opcode1 >= 0x20 && opcode1 <= 0x27)) {  // 100xxx
1741      // Load/store single data item
1742      uint16_t opA = (instr >> 12) & 0xF;
1743      if (opA == 0x5) {
1744        uint16_t opB = (instr >> 9) & 0x7;
1745        ThumbRegister Rm(instr, 6);
1746        ThumbRegister Rn(instr, 3);
1747        ThumbRegister Rt(instr, 0);
1748        switch (opB) {
1749          case 0: opcode << "str"; break;
1750          case 1: opcode << "strh"; break;
1751          case 2: opcode << "strb"; break;
1752          case 3: opcode << "ldrsb"; break;
1753          case 4: opcode << "ldr"; break;
1754          case 5: opcode << "ldrh"; break;
1755          case 6: opcode << "ldrb"; break;
1756          case 7: opcode << "ldrsh"; break;
1757        }
1758        args << Rt << ", [" << Rn << ", " << Rm << "]";
1759      } else if (opA == 9) {
1760        uint16_t opB = (instr >> 11) & 1;
1761        ThumbRegister Rt(instr, 8);
1762        uint16_t imm8 = instr & 0xFF;
1763        opcode << (opB == 0 ? "str" : "ldr");
1764        args << Rt << ", [sp, #" << (imm8 << 2) << "]";
1765      } else {
1766        uint16_t imm5 = (instr >> 6) & 0x1F;
1767        uint16_t opB = (instr >> 11) & 1;
1768        ThumbRegister Rn(instr, 3);
1769        ThumbRegister Rt(instr, 0);
1770        switch (opA) {
1771          case 6:
1772            imm5 <<= 2;
1773            opcode << (opB == 0 ? "str" : "ldr");
1774            break;
1775          case 7:
1776            imm5 <<= 0;
1777            opcode << (opB == 0 ? "strb" : "ldrb");
1778            break;
1779          case 8:
1780            imm5 <<= 1;
1781            opcode << (opB == 0 ? "strh" : "ldrh");
1782            break;
1783        }
1784        args << Rt << ", [" << Rn << ", #" << imm5 << "]";
1785      }
1786    } else if (opcode1 >= 0x34 && opcode1 <= 0x37) {  // 1101xx
1787      int8_t imm8 = instr & 0xFF;
1788      uint32_t cond = (instr >> 8) & 0xF;
1789      opcode << "b";
1790      DumpCond(opcode, cond);
1791      DumpBranchTarget(args, instr_ptr + 4, (imm8 << 1));
1792    } else if ((instr & 0xF800) == 0xA800) {
1793      // Generate SP-relative address
1794      ThumbRegister rd(instr, 8);
1795      int imm8 = instr & 0xFF;
1796      opcode << "add";
1797      args << rd << ", sp, #" << (imm8 << 2);
1798    } else if ((instr & 0xF000) == 0xB000) {
1799      // Miscellaneous 16-bit instructions
1800      uint16_t opcode2 = (instr >> 5) & 0x7F;
1801      switch (opcode2) {
1802        case 0x00: case 0x01: case 0x02: case 0x03: case 0x04: case 0x05: case 0x06: case 0x07: {
1803          // Add immediate to SP        - 1011 00000 ii iiiii
1804          // Subtract immediate from SP - 1011 00001 ii iiiii
1805          int imm7 = instr & 0x7F;
1806          opcode << ((opcode2 & 4) == 0 ? "add" : "sub");
1807          args << "sp, sp, #" << (imm7 << 2);
1808          break;
1809        }
1810        case 0x08: case 0x09: case 0x0A: case 0x0B:  // 0001xxx
1811        case 0x0C: case 0x0D: case 0x0E: case 0x0F:
1812        case 0x18: case 0x19: case 0x1A: case 0x1B:  // 0011xxx
1813        case 0x1C: case 0x1D: case 0x1E: case 0x1F:
1814        case 0x48: case 0x49: case 0x4A: case 0x4B:  // 1001xxx
1815        case 0x4C: case 0x4D: case 0x4E: case 0x4F:
1816        case 0x58: case 0x59: case 0x5A: case 0x5B:  // 1011xxx
1817        case 0x5C: case 0x5D: case 0x5E: case 0x5F: {
1818          // CBNZ, CBZ
1819          uint16_t op = (instr >> 11) & 1;
1820          uint16_t i = (instr >> 9) & 1;
1821          uint16_t imm5 = (instr >> 3) & 0x1F;
1822          ThumbRegister Rn(instr, 0);
1823          opcode << (op != 0 ? "cbnz" : "cbz");
1824          uint32_t imm32 = (i << 6) | (imm5 << 1);
1825          args << Rn << ", ";
1826          DumpBranchTarget(args, instr_ptr + 4, imm32);
1827          break;
1828        }
1829        case 0x20: case 0x21: case 0x22: case 0x23: case 0x24: case 0x25: case 0x26: case 0x27:
1830        case 0x28: case 0x29: case 0x2A: case 0x2B: case 0x2C: case 0x2D: case 0x2E: case 0x2F: {
1831          opcode << "push";
1832          args << RegisterList((instr & 0xFF) | ((instr & 0x100) << 6));
1833          break;
1834        }
1835        case 0x60: case 0x61: case 0x62: case 0x63: case 0x64: case 0x65: case 0x66: case 0x67:
1836        case 0x68: case 0x69: case 0x6A: case 0x6B: case 0x6C: case 0x6D: case 0x6E: case 0x6F: {
1837          opcode << "pop";
1838          args << RegisterList((instr & 0xFF) | ((instr & 0x100) << 7));
1839          break;
1840        }
1841        case 0x70: case 0x71: case 0x72: case 0x73: case 0x74: case 0x75: case 0x76: case 0x77: {
1842          opcode << "bkpt";
1843          args << "#" << (instr & 0xFF);
1844          break;
1845        }
1846        case 0x50: case 0x51:    // 101000x
1847        case 0x52: case 0x53:    // 101001x
1848        case 0x56: case 0x57: {  // 101011x
1849          uint16_t op = (instr >> 6) & 3;
1850          opcode << kThumbReverseOperations[op];
1851          ThumbRegister Rm(instr, 3);
1852          ThumbRegister Rd(instr, 0);
1853          args << Rd << ", " << Rm;
1854          break;
1855        }
1856        case 0x78: case 0x79: case 0x7A: case 0x7B:  // 1111xxx
1857        case 0x7C: case 0x7D: case 0x7E: case 0x7F: {
1858          // If-Then, and hints
1859          uint16_t opA = (instr >> 4) & 0xF;
1860          uint16_t opB = instr & 0xF;
1861          if (opB == 0) {
1862            switch (opA) {
1863              case 0: opcode << "nop"; break;
1864              case 1: opcode << "yield"; break;
1865              case 2: opcode << "wfe";  break;
1866              case 3: opcode << "sev"; break;
1867              default: break;
1868            }
1869          } else {
1870            uint32_t first_cond = opA;
1871            uint32_t mask = opB;
1872            opcode << "it";
1873
1874            // Flesh out the base "it" opcode with the specific collection of 't's and 'e's,
1875            // and store up the actual condition codes we'll want to add to the next few opcodes.
1876            size_t count = 3 - CTZ(mask);
1877            it_conditions_.resize(count + 2);  // Plus the implicit 't', plus the "" for the IT itself.
1878            for (size_t i = 0; i < count; ++i) {
1879              bool positive_cond = ((first_cond & 1) != 0);
1880              bool positive_mask = ((mask & (1 << (3 - i))) != 0);
1881              if (positive_mask == positive_cond) {
1882                opcode << 't';
1883                it_conditions_[i] = kConditionCodeNames[first_cond];
1884              } else {
1885                opcode << 'e';
1886                it_conditions_[i] = kConditionCodeNames[first_cond ^ 1];
1887              }
1888            }
1889            it_conditions_[count] = kConditionCodeNames[first_cond];  // The implicit 't'.
1890
1891            it_conditions_[count + 1] = "";  // No condition code for the IT itself...
1892            DumpCond(args, first_cond);  // ...because it's considered an argument.
1893          }
1894          break;
1895        }
1896        default:
1897          break;
1898      }
1899    } else if (((instr & 0xF000) == 0x5000) || ((instr & 0xE000) == 0x6000) ||
1900        ((instr & 0xE000) == 0x8000)) {
1901      // Load/store single data item
1902      uint16_t opA = instr >> 12;
1903      // uint16_t opB = (instr >> 9) & 7;
1904      switch (opA) {
1905        case 0x6: {
1906          // STR Rt, [Rn, #imm] - 01100 iiiii nnn ttt
1907          // LDR Rt, [Rn, #imm] - 01101 iiiii nnn ttt
1908          uint16_t imm5 = (instr >> 6) & 0x1F;
1909          ThumbRegister Rn(instr, 3);
1910          ThumbRegister Rt(instr, 0);
1911          opcode << ((instr & 0x800) == 0 ? "str" : "ldr");
1912          args << Rt << ", [" << Rn << ", #" << (imm5 << 2) << "]";
1913          break;
1914        }
1915        case 0x9: {
1916          // STR Rt, [SP, #imm] - 01100 ttt iiiiiiii
1917          // LDR Rt, [SP, #imm] - 01101 ttt iiiiiiii
1918          uint16_t imm8 = instr & 0xFF;
1919          ThumbRegister Rt(instr, 8);
1920          opcode << ((instr & 0x800) == 0 ? "str" : "ldr");
1921          args << Rt << ", [sp, #" << (imm8 << 2) << "]";
1922          break;
1923        }
1924        default:
1925          break;
1926      }
1927    } else if (opcode1 == 0x38 || opcode1 == 0x39) {
1928      uint16_t imm11 = instr & 0x7FFF;
1929      int32_t imm32 = imm11 << 1;
1930      imm32 = (imm32 << 20) >> 20;  // sign extend 12 bit immediate
1931      opcode << "b";
1932      DumpBranchTarget(args, instr_ptr + 4, imm32);
1933    }
1934
1935    // Apply any IT-block conditions to the opcode if necessary.
1936    if (!it_conditions_.empty()) {
1937      opcode << it_conditions_.back();
1938      it_conditions_.pop_back();
1939    }
1940
1941    os << FormatInstructionPointer(instr_ptr)
1942       << StringPrintf(": %04x    \t%-7s ", instr, opcode.str().c_str())
1943       << args.str() << '\n';
1944  }
1945  return 2;
1946}
1947
1948}  // namespace arm
1949}  // namespace art
1950