• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 <iostream>
20 
21 #include "base/logging.h"
22 #include "base/stringprintf.h"
23 #include "thread.h"
24 
25 namespace art {
26 namespace arm {
27 
DisassemblerArm()28 DisassemblerArm::DisassemblerArm() {
29 }
30 
Dump(std::ostream & os,const uint8_t * begin)31 size_t DisassemblerArm::Dump(std::ostream& os, const uint8_t* begin) {
32   if ((reinterpret_cast<intptr_t>(begin) & 1) == 0) {
33     DumpArm(os, begin);
34     return 4;
35   } else {
36     // remove thumb specifier bits
37     begin = reinterpret_cast<const uint8_t*>(reinterpret_cast<uintptr_t>(begin) & ~1);
38     return DumpThumb16(os, begin);
39   }
40 }
41 
Dump(std::ostream & os,const uint8_t * begin,const uint8_t * end)42 void DisassemblerArm::Dump(std::ostream& os, const uint8_t* begin, const uint8_t* end) {
43   if ((reinterpret_cast<intptr_t>(begin) & 1) == 0) {
44     for (const uint8_t* cur = begin; cur < end; cur += 4) {
45       DumpArm(os, cur);
46     }
47   } else {
48     // remove thumb specifier bits
49     begin = reinterpret_cast<const uint8_t*>(reinterpret_cast<uintptr_t>(begin) & ~1);
50     end = reinterpret_cast<const uint8_t*>(reinterpret_cast<uintptr_t>(end) & ~1);
51     for (const uint8_t* cur = begin; cur < end;) {
52       cur += DumpThumb16(os, cur);
53     }
54   }
55 }
56 
57 static const char* kConditionCodeNames[] = {
58   "eq",  // 0000 - equal
59   "ne",  // 0001 - not-equal
60   "cs",  // 0010 - carry-set, greater than, equal or unordered
61   "cc",  // 0011 - carry-clear, less than
62   "mi",  // 0100 - minus, negative
63   "pl",  // 0101 - plus, positive or zero
64   "vs",  // 0110 - overflow
65   "vc",  // 0111 - no overflow
66   "hi",  // 1000 - unsigned higher
67   "ls",  // 1001 - unsigned lower or same
68   "ge",  // 1010 - signed greater than or equal
69   "lt",  // 1011 - signed less than
70   "gt",  // 1100 - signed greater than
71   "le",  // 1101 - signed less than or equal
72   "",    // 1110 - always
73   "nv",  // 1111 - never (mostly obsolete, but might be a clue that we're mistranslating)
74 };
75 
DumpCond(std::ostream & os,uint32_t cond)76 void DisassemblerArm::DumpCond(std::ostream& os, uint32_t cond) {
77   if (cond < 15) {
78     os << kConditionCodeNames[cond];
79   } else {
80     os << "Unexpected condition: " << cond;
81   }
82 }
83 
DumpBranchTarget(std::ostream & os,const uint8_t * instr_ptr,int32_t imm32)84 void DisassemblerArm::DumpBranchTarget(std::ostream& os, const uint8_t* instr_ptr, int32_t imm32) {
85   os << StringPrintf("%+d (%p)", imm32, instr_ptr + imm32);
86 }
87 
ReadU16(const uint8_t * ptr)88 static uint32_t ReadU16(const uint8_t* ptr) {
89   return ptr[0] | (ptr[1] << 8);
90 }
91 
ReadU32(const uint8_t * ptr)92 static uint32_t ReadU32(const uint8_t* ptr) {
93   return ptr[0] | (ptr[1] << 8) | (ptr[2] << 16) | (ptr[3] << 24);
94 }
95 
96 static const char* kDataProcessingOperations[] = {
97   "and", "eor", "sub", "rsb", "add", "adc", "sbc", "rsc",
98   "tst", "teq", "cmp", "cmn", "orr", "mov", "bic", "mvn",
99 };
100 
101 static const char* kThumbDataProcessingOperations[] = {
102   "and", "eor", "lsl", "lsr", "asr", "adc", "sbc", "ror",
103   "tst", "rsb", "cmp", "cmn", "orr", "mul", "bic", "mvn",
104 };
105 
106 struct ArmRegister {
ArmRegisterart::arm::ArmRegister107   explicit ArmRegister(uint32_t r) : r(r) { CHECK_LE(r, 15U); }
ArmRegisterart::arm::ArmRegister108   ArmRegister(uint32_t instruction, uint32_t at_bit) : r((instruction >> at_bit) & 0xf) { CHECK_LE(r, 15U); }
109   uint32_t r;
110 };
operator <<(std::ostream & os,const ArmRegister & r)111 std::ostream& operator<<(std::ostream& os, const ArmRegister& r) {
112   if (r.r == 13) {
113     os << "sp";
114   } else if (r.r == 14) {
115     os << "lr";
116   } else if (r.r == 15) {
117     os << "pc";
118   } else {
119     os << "r" << r.r;
120   }
121   return os;
122 }
123 
124 struct ThumbRegister : ArmRegister {
ThumbRegisterart::arm::ThumbRegister125   ThumbRegister(uint16_t instruction, uint16_t at_bit) : ArmRegister((instruction >> at_bit) & 0x7) {}
126 };
127 
128 struct Rm {
Rmart::arm::Rm129   explicit Rm(uint32_t instruction) : shift((instruction >> 4) & 0xff), rm(instruction & 0xf) {}
130   uint32_t shift;
131   ArmRegister rm;
132 };
operator <<(std::ostream & os,const Rm & r)133 std::ostream& operator<<(std::ostream& os, const Rm& r) {
134   os << r.rm;
135   if (r.shift != 0) {
136     os << "-shift-" << r.shift;  // TODO
137   }
138   return os;
139 }
140 
141 struct ShiftedImmediate {
ShiftedImmediateart::arm::ShiftedImmediate142   explicit ShiftedImmediate(uint32_t instruction) {
143     uint32_t rotate = ((instruction >> 8) & 0xf);
144     uint32_t imm = (instruction & 0xff);
145     value = (imm >> (2 * rotate)) | (imm << (32 - (2 * rotate)));
146   }
147   uint32_t value;
148 };
operator <<(std::ostream & os,const ShiftedImmediate & rhs)149 std::ostream& operator<<(std::ostream& os, const ShiftedImmediate& rhs) {
150   os << "#" << rhs.value;
151   return os;
152 }
153 
154 struct RegisterList {
RegisterListart::arm::RegisterList155   explicit RegisterList(uint32_t instruction) : register_list(instruction & 0xffff) {}
156   uint32_t register_list;
157 };
operator <<(std::ostream & os,const RegisterList & rhs)158 std::ostream& operator<<(std::ostream& os, const RegisterList& rhs) {
159   if (rhs.register_list == 0) {
160     os << "<no register list?>";
161     return os;
162   }
163   os << "{";
164   bool first = true;
165   for (size_t i = 0; i < 16; i++) {
166     if ((rhs.register_list & (1 << i)) != 0) {
167       if (first) {
168         first = false;
169       } else {
170         os << ", ";
171       }
172       os << ArmRegister(i);
173     }
174   }
175   os << "}";
176   return os;
177 }
178 
DumpArm(std::ostream & os,const uint8_t * instr_ptr)179 void DisassemblerArm::DumpArm(std::ostream& os, const uint8_t* instr_ptr) {
180   uint32_t instruction = ReadU32(instr_ptr);
181   uint32_t cond = (instruction >> 28) & 0xf;
182   uint32_t op1 = (instruction >> 25) & 0x7;
183   std::string opcode;
184   std::string suffixes;
185   std::ostringstream args;
186   switch (op1) {
187     case 0:
188     case 1:  // Data processing instructions.
189       {
190         if ((instruction & 0x0ff000f0) == 0x01200070) {  // BKPT
191           opcode = "bkpt";
192           uint32_t imm12 = (instruction >> 8) & 0xfff;
193           uint32_t imm4 = (instruction & 0xf);
194           args << '#' << ((imm12 << 4) | imm4);
195           break;
196         }
197         if ((instruction & 0x0fffffd0) == 0x012fff10) {  // BX and BLX (register)
198           opcode = (((instruction >> 5) & 1) ? "blx" : "bx");
199           args << ArmRegister(instruction & 0xf);
200           break;
201         }
202         bool i = (instruction & (1 << 25)) != 0;
203         bool s = (instruction & (1 << 20)) != 0;
204         uint32_t op = (instruction >> 21) & 0xf;
205         opcode = kDataProcessingOperations[op];
206         bool implicit_s = ((op & ~3) == 8);  // TST, TEQ, CMP, and CMN.
207         if (implicit_s) {
208           // Rd is unused (and not shown), and we don't show the 's' suffix either.
209         } else {
210           if (s) {
211             suffixes += 's';
212           }
213           args << ArmRegister(instruction, 12) << ", ";
214         }
215         if (i) {
216           args << ArmRegister(instruction, 16) << ", " << ShiftedImmediate(instruction);
217         } else {
218           args << Rm(instruction);
219         }
220       }
221       break;
222     case 2:  // Load/store word and unsigned byte.
223       {
224         bool p = (instruction & (1 << 24)) != 0;
225         bool b = (instruction & (1 << 22)) != 0;
226         bool w = (instruction & (1 << 21)) != 0;
227         bool l = (instruction & (1 << 20)) != 0;
228         opcode = StringPrintf("%s%s", (l ? "ldr" : "str"), (b ? "b" : ""));
229         args << ArmRegister(instruction, 12) << ", ";
230         ArmRegister rn(instruction, 16);
231         if (rn.r == 0xf) {
232           UNIMPLEMENTED(FATAL) << "literals";
233         } else {
234           bool wback = !p || w;
235           uint32_t offset = (instruction & 0xfff);
236           if (p && !wback) {
237             args << "[" << rn << ", #" << offset << "]";
238           } else if (p && wback) {
239             args << "[" << rn << ", #" << offset << "]!";
240           } else if (!p && wback) {
241             args << "[" << rn << "], #" << offset;
242           } else {
243             LOG(FATAL) << p << " " << w;
244           }
245           if (rn.r == 9) {
246             args << "  ; ";
247             Thread::DumpThreadOffset(args, offset, 4);
248           }
249         }
250       }
251       break;
252     case 4:  // Load/store multiple.
253       {
254         bool p = (instruction & (1 << 24)) != 0;
255         bool u = (instruction & (1 << 23)) != 0;
256         bool w = (instruction & (1 << 21)) != 0;
257         bool l = (instruction & (1 << 20)) != 0;
258         opcode = StringPrintf("%s%c%c", (l ? "ldm" : "stm"), (u ? 'i' : 'd'), (p ? 'b' : 'a'));
259         args << ArmRegister(instruction, 16) << (w ? "!" : "") << ", " << RegisterList(instruction);
260       }
261       break;
262     case 5:  // Branch/branch with link.
263       {
264         bool bl = (instruction & (1 << 24)) != 0;
265         opcode = (bl ? "bl" : "b");
266         int32_t imm26 = (instruction & 0xffffff) << 2;
267         int32_t imm32 = (imm26 << 6) >> 6;  // Sign extend.
268         DumpBranchTarget(args, instr_ptr + 8, imm32);
269       }
270       break;
271     default:
272       opcode = "???";
273       break;
274     }
275     opcode += kConditionCodeNames[cond];
276     opcode += suffixes;
277     // TODO: a more complete ARM disassembler could generate wider opcodes.
278     os << StringPrintf("%p: %08x\t%-7s ", instr_ptr, instruction, opcode.c_str()) << args.str() << '\n';
279 }
280 
DumpThumb32(std::ostream & os,const uint8_t * instr_ptr)281 size_t DisassemblerArm::DumpThumb32(std::ostream& os, const uint8_t* instr_ptr) {
282   uint32_t instr = (ReadU16(instr_ptr) << 16) | ReadU16(instr_ptr + 2);
283   // |111|1 1|1000000|0000|1111110000000000|
284   // |5 3|2 1|0987654|3  0|5    0    5    0|
285   // |---|---|-------|----|----------------|
286   // |332|2 2|2222222|1111|1111110000000000|
287   // |1 9|8 7|6543210|9  6|5    0    5    0|
288   // |---|---|-------|----|----------------|
289   // |111|op1| op2   |    |                |
290   uint32_t op1 = (instr >> 27) & 3;
291   if (op1 == 0) {
292     return DumpThumb16(os, instr_ptr);
293   }
294 
295   uint32_t op2 = (instr >> 20) & 0x7F;
296   std::ostringstream opcode;
297   std::ostringstream args;
298   switch (op1) {
299     case 0:
300       break;
301     case 1:
302       if ((op2 & 0x64) == 0) {  // 00x x0xx
303         // |111|11|10|00|0|00|0000|1111110000000000|
304         // |5 3|21|09|87|6|54|3  0|5    0    5    0|
305         // |---|--|--|--|-|--|----|----------------|
306         // |332|22|22|22|2|22|1111|1111110000000000|
307         // |1 9|87|65|43|2|10|9  6|5    0    5    0|
308         // |---|--|--|--|-|--|----|----------------|
309         // |111|01|00|op|0|WL| Rn |                |
310         // |111|01| op2      |    |                |
311         // STM - 111 01 00-01-0-W0 nnnn rrrrrrrrrrrrrrrr
312         // LDM - 111 01 00-01-0-W1 nnnn rrrrrrrrrrrrrrrr
313         // PUSH- 111 01 00-01-0-10 1101 0M0rrrrrrrrrrrrr
314         // POP - 111 01 00-01-0-11 1101 PM0rrrrrrrrrrrrr
315         uint32_t op = (instr >> 23) & 3;
316         uint32_t W = (instr >> 21) & 1;
317         uint32_t L = (instr >> 20) & 1;
318         ArmRegister Rn(instr, 16);
319         if (op == 1 || op == 2) {
320           if (op == 1) {
321             if (L == 0) {
322               opcode << "stm";
323               args << Rn << (W == 0 ? "" : "!") << ", ";
324             } else {
325               if (Rn.r != 13) {
326                 opcode << "ldm";
327                 args << Rn << (W == 0 ? "" : "!") << ", ";
328               } else {
329                 opcode << "pop";
330               }
331             }
332           } else {
333             if (L == 0) {
334               if (Rn.r != 13) {
335                 opcode << "stmdb";
336                 args << Rn << (W == 0 ? "" : "!") << ", ";
337               } else {
338                 opcode << "push";
339               }
340             } else {
341               opcode << "ldmdb";
342               args << Rn << (W == 0 ? "" : "!") << ", ";
343             }
344           }
345           args << RegisterList(instr);
346         }
347       } else if ((op2 & 0x64) == 4) {  // 00x x1xx
348         uint32_t op3 = (instr >> 23) & 3;
349         uint32_t op4 = (instr >> 20) & 3;
350         // uint32_t op5 = (instr >> 4) & 0xF;
351         ArmRegister Rn(instr, 16);
352         ArmRegister Rt(instr, 12);
353         uint32_t imm8 = instr & 0xFF;
354         if (op3 == 0 && op4 == 0) {  // STREX
355           ArmRegister Rd(instr, 8);
356           opcode << "strex";
357           args << Rd << ", " << Rt << ", [" << Rn << ", #" << (imm8 << 2) << "]";
358         } else if (op3 == 0 && op4 == 1) {  // LDREX
359           opcode << "ldrex";
360           args << Rt << ", [" << Rn << ", #" << (imm8 << 2) << "]";
361         }
362       } else if ((op2 & 0x60) == 0x20) {  // 01x xxxx
363         // Data-processing (shifted register)
364         // |111|1110|0000|0|0000|1111|1100|00|00|0000|
365         // |5 3|2109|8765|4|3  0|5   |10 8|7 |5 |3  0|
366         // |---|----|----|-|----|----|----|--|--|----|
367         // |332|2222|2222|2|1111|1111|1100|00|00|0000|
368         // |1 9|8765|4321|0|9  6|5   |10 8|7 |5 |3  0|
369         // |---|----|----|-|----|----|----|--|--|----|
370         // |111|0101| op3|S| Rn |imm3| Rd |i2|ty| Rm |
371         uint32_t op3 = (instr >> 21) & 0xF;
372         uint32_t S = (instr >> 20) & 1;
373         uint32_t imm3 = ((instr >> 12) & 0x7);
374         uint32_t imm2 = ((instr >> 6) & 0x3);
375         uint32_t imm5 = ((imm3 << 3) | imm2) & 0x1F;
376         uint32_t shift_type = ((instr >> 4) & 0x2);
377         ArmRegister Rd(instr, 8);
378         ArmRegister Rn(instr, 16);
379         ArmRegister Rm(instr, 0);
380         switch (op3) {
381           case 0x0:
382             if (Rd.r != 0xF) {
383               opcode << "and";
384             } else {
385               if (S != 1U) {
386                 opcode << "UNKNOWN TST-" << S;
387                 break;
388               }
389               opcode << "tst";
390               S = 0;  // don't print 's'
391             }
392             break;
393           case 0x1: opcode << "bic"; break;
394           case 0x2:
395             if (Rn.r != 0xF) {
396               opcode << "orr";
397             } else {
398               // TODO: use canonical form if there is a shift (lsl, ...).
399               opcode << "mov";
400             }
401             break;
402           case 0x3:
403             if (Rn.r != 0xF) {
404               opcode << "orn";
405             } else {
406               opcode << "mvn";
407             }
408             break;
409           case 0x4:
410             if (Rd.r != 0xF) {
411               opcode << "eor";
412             } else {
413               if (S != 1U) {
414                 opcode << "UNKNOWN TEQ-" << S;
415                 break;
416               }
417               opcode << "teq";
418               S = 0;  // don't print 's'
419             }
420             break;
421           case 0x6: opcode << "pkh"; break;
422           case 0x8:
423             if (Rd.r != 0xF) {
424               opcode << "add";
425             } else {
426               if (S != 1U) {
427                 opcode << "UNKNOWN CMN-" << S;
428                 break;
429               }
430               opcode << "cmn";
431               S = 0;  // don't print 's'
432             }
433             break;
434           case 0xA: opcode << "adc"; break;
435           case 0xB: opcode << "sbc"; break;
436           case 0xD:
437             if (Rd.r != 0xF) {
438               opcode << "sub";
439             } else {
440               if (S != 1U) {
441                 opcode << "UNKNOWN CMP-" << S;
442                 break;
443               }
444               opcode << "cmp";
445               S = 0;  // don't print 's'
446             }
447             break;
448           case 0xE: opcode << "rsb"; break;
449           default: opcode << "UNKNOWN DPSR-" << op3; break;
450         }
451 
452         if (S == 1) {
453           opcode << "s";
454         }
455         opcode << ".w";
456 
457         if (Rd.r != 0xF) {
458           args << Rd << ", ";
459         }
460         if (Rn.r != 0xF) {
461           args << Rn << ", ";
462         }
463         args << Rm;
464 
465         // Shift operand.
466         bool noShift = (imm5 == 0 && shift_type != 0x3);
467         if (!noShift) {
468           args << ", ";
469           switch (shift_type) {
470             case 0x0: args << "lsl"; break;
471             case 0x1: args << "lsr"; break;
472             case 0x2: args << "asr"; break;
473             case 0x3:
474               if (imm5 == 0) {
475                 args << "rrx";
476               } else {
477                 args << "ror";
478               }
479               break;
480           }
481           if (shift_type != 0x3 /* rrx */) {
482             args << StringPrintf(" #%d", imm5);
483           }
484         }
485 
486       } else if ((op2 & 0x40) == 0x40) {  // 1xx xxxx
487         // Co-processor instructions
488         // |111|1|11|000000|0000|1111|1100|000|0  |0000|
489         // |5 3|2|10|987654|3  0|54 2|10 8|7 5|4  |   0|
490         // |---|-|--|------|----|----|----|---|---|----|
491         // |332|2|22|222222|1111|1111|1100|000|0  |0000|
492         // |1 9|8|76|543210|9  6|54 2|10 8|7 5|4  |   0|
493         // |---|-|--|------|----|----|----|---|---|----|
494         // |111| |11| op3  | Rn |    |copr|   |op4|    |
495         uint32_t op3 = (instr >> 20) & 0x3F;
496         uint32_t coproc = (instr >> 8) & 0xF;
497         uint32_t op4 = (instr >> 4) & 0x1;
498         if ((op3 == 2 || op3 == 2 || op3 == 6 || op3 == 7) ||  // 00x1x
499             (op3 >= 8 && op3 <= 15) || (op3 >= 16 && op3 <= 31)) {  // 001xxx, 01xxxx
500           // Extension register load/store instructions
501           // |111|1|110|00000|0000|1111|110|000000000|
502           // |5 3|2|109|87654|3  0|54 2|10 |87 54   0|
503           // |---|-|---|-----|----|----|---|---------|
504           // |332|2|222|22222|1111|1111|110|000000000|
505           // |1 9|8|765|43210|9  6|54 2|10 |87 54   0|
506           // |---|-|---|-----|----|----|---|---------|
507           // |111|T|110| op3 | Rn |    |101|         |
508           //  111 0 110 01001 0011 0000 101 000000011 - ec930a03
509           if (op3 == 9 || op3 == 0xD) {  // VLDM
510             //  1110 110 PUDW1 nnnn dddd 101S iiii iiii
511             uint32_t P = (instr >> 24) & 1;
512             uint32_t U = (instr >> 23) & 1;
513             uint32_t D = (instr >> 22) & 1;
514             uint32_t W = (instr >> 21) & 1;
515             uint32_t S = (instr >> 8) & 1;
516             ArmRegister Rn(instr, 16);
517             uint32_t Vd = (instr >> 12) & 0xF;
518             uint32_t imm8 = instr & 0xFF;
519             uint32_t d = (S == 0 ? ((Vd << 1) | D) : (Vd | (D << 4)));
520             if (P == 0 && U == 0 && W == 0) {
521               // TODO: 64bit transfers between ARM core and extension registers.
522             } else if (P == 0 && U == 1 && Rn.r == 13) {  // VPOP
523               opcode << "vpop" << (S == 0 ? ".f64" : ".f32");
524               args << d << " .. " << (d + imm8);
525             } else if (P == 1 && W == 0) {  // VLDR
526               opcode << "vldr" << (S == 0 ? ".f64" : ".f32");
527               args << d << ", [" << Rn << ", #" << imm8 << "]";
528             } else {  // VLDM
529               opcode << "vldm" << (S == 0 ? ".f64" : ".f32");
530               args << Rn << ", " << d << " .. " << (d + imm8);
531             }
532           }
533         } else if ((op3 & 0x30) == 0x20 && op4 == 0) {  // 10 xxxx ... 0
534           if ((coproc & 0xE) == 0xA) {
535             // VFP data-processing instructions
536             // |111|1|1100|0000|0000|1111|110|0|00  |0|0|0000|
537             // |5 3|2|1098|7654|3  0|54 2|10 |8|76  |5|4|3  0|
538             // |---|-|----|----|----|----|---|-|----|-|-|----|
539             // |332|2|2222|2222|1111|1111|110|0|00  |0|0|0000|
540             // |1 9|8|7654|3210|9  6|54 2|109|8|76  |5|4|3  0|
541             // |---|-|----|----|----|----|---|-|----|-|-|----|
542             // |111|T|1110|opc1|opc2|    |101| |opc3| | |    |
543             //  111 0 1110|1111 0100 1110 101 0 01   1 0 1001 - eef4ea69
544             uint32_t opc1 = (instr >> 20) & 0xF;
545             uint32_t opc2 = (instr >> 16) & 0xF;
546             uint32_t opc3 = (instr >> 6) & 0x3;
547             if ((opc1 & 0xB) == 0xB) {  // 1x11
548               // Other VFP data-processing instructions.
549               uint32_t D  = (instr >> 22) & 0x1;
550               uint32_t Vd = (instr >> 12) & 0xF;
551               uint32_t sz = (instr >> 8) & 1;
552               uint32_t M  = (instr >> 5) & 1;
553               uint32_t Vm = instr & 0xF;
554               bool dp_operation = sz == 1;
555               switch (opc2) {
556                 case 0x1:  // Vneg/Vsqrt
557                   //  1110 11101 D 11 0001 dddd 101s o1M0 mmmm
558                   opcode << (opc3 == 1 ? "vneg" : "vsqrt") << (dp_operation ? ".f64" : ".f32");
559                   if (dp_operation) {
560                     args << "f" << ((D << 4) | Vd) << ", " << "f" << ((M << 4) | Vm);
561                   } else {
562                     args << "f" << ((Vd << 1) | D) << ", " << "f" << ((Vm << 1) | M);
563                   }
564                   break;
565                 case 0x4: case 0x5:  {  // Vector compare
566                   // 1110 11101 D 11 0100 dddd 101 sE1M0 mmmm
567                   opcode << (opc3 == 1 ? "vcmp" : "vcmpe") << (dp_operation ? ".f64" : ".f32");
568                   if (dp_operation) {
569                     args << "f" << ((D << 4) | Vd) << ", " << "f" << ((M << 4) | Vm);
570                   } else {
571                     args << "f" << ((Vd << 1) | D) << ", " << "f" << ((Vm << 1) | M);
572                   }
573                   break;
574                 }
575               }
576             }
577           }
578         } else if ((op3 & 0x30) == 0x30) {  // 11 xxxx
579           // Advanced SIMD
580           if ((instr & 0xFFBF0ED0) == 0xeeb10ac0) {  // Vsqrt
581             //  1110 11101 D 11 0001 dddd 101S 11M0 mmmm
582             //  1110 11101 0 11 0001 1101 1011 1100 1000 - eeb1dbc8
583             uint32_t D = (instr >> 22) & 1;
584             uint32_t Vd = (instr >> 12) & 0xF;
585             uint32_t sz = (instr >> 8) & 1;
586             uint32_t M = (instr >> 5) & 1;
587             uint32_t Vm = instr & 0xF;
588             bool dp_operation = sz == 1;
589             opcode << "vsqrt" << (dp_operation ? ".f64" : ".f32");
590             if (dp_operation) {
591               args << "f" << ((D << 4) | Vd) << ", " << "f" << ((M << 4) | Vm);
592             } else {
593               args << "f" << ((Vd << 1) | D) << ", " << "f" << ((Vm << 1) | M);
594             }
595           }
596         }
597       }
598       break;
599     case 2:
600       if ((instr & 0x8000) == 0 && (op2 & 0x20) == 0) {
601         // Data-processing (modified immediate)
602         // |111|11|10|0000|0|0000|1|111|1100|00000000|
603         // |5 3|21|09|8765|4|3  0|5|4 2|10 8|7 5    0|
604         // |---|--|--|----|-|----|-|---|----|--------|
605         // |332|22|22|2222|2|1111|1|111|1100|00000000|
606         // |1 9|87|65|4321|0|9  6|5|4 2|10 8|7 5    0|
607         // |---|--|--|----|-|----|-|---|----|--------|
608         // |111|10|i0| op3|S| Rn |0|iii| Rd |iiiiiiii|
609         //  111 10 x0 xxxx x xxxx opxxx xxxx xxxxxxxx
610         uint32_t i = (instr >> 26) & 1;
611         uint32_t op3 = (instr >> 21) & 0xF;
612         uint32_t S = (instr >> 20) & 1;
613         ArmRegister Rn(instr, 16);
614         uint32_t imm3 = (instr >> 12) & 7;
615         ArmRegister Rd(instr, 8);
616         uint32_t imm8 = instr & 0xFF;
617         int32_t imm32 = (i << 11) | (imm3 << 8) | imm8;
618         if (Rn.r == 0xF && (op3 == 0x2 || op3 == 0x3)) {
619           if (op3 == 0x2) {
620             opcode << "mov";
621             if (S == 1) {
622               opcode << "s";
623             }
624             opcode << ".w";
625           } else {
626             opcode << "mvn";
627             if (S == 1) {
628               opcode << "s";
629             }
630           }
631           args << Rd << ", ThumbExpand(" << imm32 << ")";
632         } else if (Rd.r == 0xF && S == 1 &&
633                    (op3 == 0x0 || op3 == 0x4 || op3 == 0x8 || op3 == 0xD)) {
634           if (op3 == 0x0) {
635             opcode << "tst";
636           } else if (op3 == 0x4) {
637             opcode << "teq";
638           } else if (op3 == 0x8) {
639             opcode << "cmw";
640           } else {
641             opcode << "cmp.w";
642           }
643           args << Rn << ", ThumbExpand(" << imm32 << ")";
644         } else {
645           switch (op3) {
646             case 0x0: opcode << "and"; break;
647             case 0x1: opcode << "bic"; break;
648             case 0x2: opcode << "orr"; break;
649             case 0x3: opcode << "orn"; break;
650             case 0x4: opcode << "eor"; break;
651             case 0x8: opcode << "add"; break;
652             case 0xA: opcode << "adc"; break;
653             case 0xB: opcode << "sbc"; break;
654             case 0xD: opcode << "sub"; break;
655             case 0xE: opcode << "rsb"; break;
656             default: opcode << "UNKNOWN DPMI-" << op3; break;
657           }
658           if (S == 1) {
659             opcode << "s";
660           }
661           args << Rd << ", " << Rn << ", ThumbExpand(" << imm32 << ")";
662         }
663       } else if ((instr & 0x8000) == 0 && (op2 & 0x20) != 0) {
664         // Data-processing (plain binary immediate)
665         // |111|11|10|00000|0000|1|111110000000000|
666         // |5 3|21|09|87654|3  0|5|4   0    5    0|
667         // |---|--|--|-----|----|-|---------------|
668         // |332|22|22|22222|1111|1|111110000000000|
669         // |1 9|87|65|43210|9  6|5|4   0    5    0|
670         // |---|--|--|-----|----|-|---------------|
671         // |111|10|x1| op3 | Rn |0|xxxxxxxxxxxxxxx|
672         uint32_t op3 = (instr >> 20) & 0x1F;
673         switch (op3) {
674           case 0x00: case 0x0A: {
675             // ADD/SUB.W Rd, Rn #imm12 - 111 10 i1 0101 0 nnnn 0 iii dddd iiiiiiii
676             ArmRegister Rd(instr, 8);
677             ArmRegister Rn(instr, 16);
678             uint32_t i = (instr >> 26) & 1;
679             uint32_t imm3 = (instr >> 12) & 0x7;
680             uint32_t imm8 = instr & 0xFF;
681             uint32_t imm12 = (i << 11) | (imm3 << 8) | imm8;
682             if (Rn.r != 0xF) {
683               opcode << (op3 == 0 ? "addw" : "subw");
684               args << Rd << ", " << Rn << ", #" << imm12;
685             } else {
686               opcode << "adr";
687               args << Rd << ", ";
688               DumpBranchTarget(args, instr_ptr + 4, (op3 == 0) ? imm12 : -imm12);
689             }
690             break;
691           }
692           case 0x04: case 0x0C: {
693             // MOVW/T Rd, #imm16     - 111 10 i0 0010 0 iiii 0 iii dddd iiiiiiii
694             ArmRegister Rd(instr, 8);
695             uint32_t i = (instr >> 26) & 1;
696             uint32_t imm3 = (instr >> 12) & 0x7;
697             uint32_t imm8 = instr & 0xFF;
698             uint32_t Rn = (instr >> 16) & 0xF;
699             uint32_t imm16 = (Rn << 12) | (i << 11) | (imm3 << 8) | imm8;
700             opcode << (op3 == 0x04 ? "movw" : "movt");
701             args << Rd << ", #" << imm16;
702             break;
703           }
704           case 0x16: {
705             // BFI Rd, Rn, #lsb, #width - 111 10 0 11 011 0 nnnn 0 iii dddd ii 0 iiiii
706             ArmRegister Rd(instr, 8);
707             ArmRegister Rn(instr, 16);
708             uint32_t msb = instr & 0x1F;
709             uint32_t imm2 = (instr >> 6) & 0x3;
710             uint32_t imm3 = (instr >> 12) & 0x7;
711             uint32_t lsb = (imm3 << 2) | imm2;
712             uint32_t width = msb - lsb + 1;
713             if (Rn.r != 0xF) {
714               opcode << "bfi";
715               args << Rd << ", " << Rn << ", #" << lsb << ", #" << width;
716             } else {
717               opcode << "bfc";
718               args << Rd << ", #" << lsb << ", #" << width;
719             }
720             break;
721           }
722           default:
723             break;
724         }
725       } else {
726         // Branches and miscellaneous control
727         // |111|11|1000000|0000|1|111|1100|00000000|
728         // |5 3|21|0987654|3  0|5|4 2|10 8|7 5    0|
729         // |---|--|-------|----|-|---|----|--------|
730         // |332|22|2222222|1111|1|111|1100|00000000|
731         // |1 9|87|6543210|9  6|5|4 2|10 8|7 5    0|
732         // |---|--|-------|----|-|---|----|--------|
733         // |111|10| op2   |    |1|op3|op4 |        |
734 
735         uint32_t op3 = (instr >> 12) & 7;
736         // uint32_t op4 = (instr >> 8) & 0xF;
737         switch (op3) {
738           case 0:
739             if ((op2 & 0x38) != 0x38) {
740               // Conditional branch
741               // |111|11|1|0000|000000|1|1|1 |1|1 |10000000000|
742               // |5 3|21|0|9876|543  0|5|4|3 |2|1 |0    5    0|
743               // |---|--|-|----|------|-|-|--|-|--|-----------|
744               // |332|22|2|2222|221111|1|1|1 |1|1 |10000000000|
745               // |1 9|87|6|5432|109  6|5|4|3 |2|1 |0    5    0|
746               // |---|--|-|----|------|-|-|--|-|--|-----------|
747               // |111|10|S|cond| imm6 |1|0|J1|0|J2| imm11     |
748               uint32_t S = (instr >> 26) & 1;
749               uint32_t J2 = (instr >> 11) & 1;
750               uint32_t J1 = (instr >> 13) & 1;
751               uint32_t imm6 = (instr >> 16) & 0x3F;
752               uint32_t imm11 = instr & 0x7FF;
753               uint32_t cond = (instr >> 22) & 0xF;
754               int32_t imm32 = (S << 20) |  (J2 << 19) | (J1 << 18) | (imm6 << 12) | (imm11 << 1);
755               imm32 = (imm32 << 11) >> 11;  // sign extend 21bit immediate
756               opcode << "b";
757               DumpCond(opcode, cond);
758               opcode << ".w";
759               DumpBranchTarget(args, instr_ptr + 4, imm32);
760             } else if (op2 == 0x3B) {
761               // Miscellaneous control instructions
762               uint32_t op5 = (instr >> 4) & 0xF;
763               switch (op5) {
764                 case 4: opcode << "dsb"; break;
765                 case 5: opcode << "dmb"; break;
766                 case 6: opcode << "isb"; break;
767               }
768             }
769             break;
770           case 2:
771             if ((op2 & 0x38) == 0x38) {
772               if (op2 == 0x7F) {
773                 opcode << "udf";
774               }
775               break;
776             }
777             // Else deliberate fall-through to B.
778           case 1: case 3: {
779             // B
780             // |111|11|1|0000|000000|11|1 |1|1 |10000000000|
781             // |5 3|21|0|9876|543  0|54|3 |2|1 |0    5    0|
782             // |---|--|-|----|------|--|--|-|--|-----------|
783             // |332|22|2|2222|221111|11|1 |1|1 |10000000000|
784             // |1 9|87|6|5  2|10   6|54|3 |2|1 |0    5    0|
785             // |---|--|-|----|------|--|--|-|--|-----------|
786             // |111|10|S|cond| imm6 |10|J1|0|J2| imm11     |
787             // |111|10|S| imm10     |10|J1|1|J2| imm11     |
788             uint32_t S = (instr >> 26) & 1;
789             uint32_t cond = (instr >> 22) & 0xF;
790             uint32_t J2 = (instr >> 11) & 1;
791             uint32_t form = (instr >> 12) & 1;
792             uint32_t J1 = (instr >> 13) & 1;
793             uint32_t imm10 = (instr >> 16) & 0x3FF;
794             uint32_t imm6  = (instr >> 16) & 0x3F;
795             uint32_t imm11 = instr & 0x7FF;
796             opcode << "b";
797             int32_t imm32;
798             if (form == 0) {
799               DumpCond(opcode, cond);
800               imm32 = (S << 20) | (J2 << 19) | (J1 << 18) | (imm6 << 12) | (imm11 << 1);
801               imm32 = (imm32 << 11) >> 11;  // sign extend 21 bit immediate.
802             } else {
803               uint32_t I1 = ~(J1 ^ S);
804               uint32_t I2 = ~(J2 ^ S);
805               imm32 = (S << 24) | (I1 << 23) | (I2 << 22) | (imm10 << 12) | (imm11 << 1);
806               imm32 = (imm32 << 8) >> 8;  // sign extend 24 bit immediate.
807             }
808             opcode << ".w";
809             DumpBranchTarget(args, instr_ptr + 4, imm32);
810             break;
811           }
812           case 4: case 6: case 5: case 7: {
813             // BL, BLX (immediate)
814             // |111|11|1|0000000000|11|1 |1|1 |10000000000|
815             // |5 3|21|0|9876543  0|54|3 |2|1 |0    5    0|
816             // |---|--|-|----------|--|--|-|--|-----------|
817             // |332|22|2|2222221111|11|1 |1|1 |10000000000|
818             // |1 9|87|6|5    0   6|54|3 |2|1 |0    5    0|
819             // |---|--|-|----------|--|--|-|--|-----------|
820             // |111|10|S| imm10    |11|J1|L|J2| imm11     |
821             uint32_t S = (instr >> 26) & 1;
822             uint32_t J2 = (instr >> 11) & 1;
823             uint32_t L = (instr >> 12) & 1;
824             uint32_t J1 = (instr >> 13) & 1;
825             uint32_t imm10 = (instr >> 16) & 0x3FF;
826             uint32_t imm11 = instr & 0x7FF;
827             if (L == 0) {
828               opcode << "bx";
829             } else {
830               opcode << "blx";
831             }
832             uint32_t I1 = ~(J1 ^ S);
833             uint32_t I2 = ~(J2 ^ S);
834             int32_t imm32 = (S << 24) | (I1 << 23) | (I2 << 22) | (imm10 << 12) | (imm11 << 1);
835             imm32 = (imm32 << 8) >> 8;  // sign extend 24 bit immediate.
836             DumpBranchTarget(args, instr_ptr + 4, imm32);
837             break;
838           }
839         }
840       }
841       break;
842     case 3:
843       switch (op2) {
844         case 0x00: case 0x02: case 0x04: case 0x06:  // 000xxx0
845         case 0x08: case 0x0A: case 0x0C: case 0x0E: {
846           // Store single data item
847           // |111|11|100|000|0|0000|1111|110000|000000|
848           // |5 3|21|098|765|4|3  0|5  2|10   6|5    0|
849           // |---|--|---|---|-|----|----|------|------|
850           // |332|22|222|222|2|1111|1111|110000|000000|
851           // |1 9|87|654|321|0|9  6|5  2|10   6|5    0|
852           // |---|--|---|---|-|----|----|------|------|
853           // |111|11|000|op3|0|    |    |  op4 |      |
854           uint32_t op3 = (instr >> 21) & 7;
855           // uint32_t op4 = (instr >> 6) & 0x3F;
856           switch (op3) {
857             case 0x0: case 0x4: {
858               // STRB Rt,[Rn,#+/-imm8]     - 111 11 00 0 0 00 0 nnnn tttt 1 PUWii ii iiii
859               // STRB Rt,[Rn,Rm,lsl #imm2] - 111 11 00 0 0 00 0 nnnn tttt 0 00000 ii mmmm
860               ArmRegister Rn(instr, 16);
861               ArmRegister Rt(instr, 12);
862               opcode << "strb";
863               if ((instr & 0x800) != 0) {
864                 uint32_t imm8 = instr & 0xFF;
865                 args << Rt << ", [" << Rn << ",#" << imm8 << "]";
866               } else {
867                 uint32_t imm2 = (instr >> 4) & 3;
868                 ArmRegister Rm(instr, 0);
869                 args << Rt << ", [" << Rn << ", " << Rm;
870                 if (imm2 != 0) {
871                   args << ", " << "lsl #" << imm2;
872                 }
873                 args << "]";
874               }
875               break;
876             }
877             case 0x2: case 0x6: {
878               ArmRegister Rn(instr, 16);
879               ArmRegister Rt(instr, 12);
880               if (op3 == 2) {
881                 if ((instr & 0x800) != 0) {
882                   // STR Rt, [Rn, #imm8] - 111 11 000 010 0 nnnn tttt 1PUWiiiiiiii
883                   uint32_t P = (instr >> 10) & 1;
884                   uint32_t U = (instr >> 9) & 1;
885                   uint32_t W = (instr >> 8) & 1;
886                   uint32_t imm8 = instr & 0xFF;
887                   int32_t imm32 = (imm8 << 24) >> 24;  // sign-extend imm8
888                   if (Rn.r == 13 && P == 1 && U == 0 && W == 1 && imm32 == 4) {
889                     opcode << "push";
890                     args << Rt;
891                   } else if (Rn.r == 15 || (P == 0 && W == 0)) {
892                     opcode << "UNDEFINED";
893                   } else {
894                     if (P == 1 && U == 1 && W == 0) {
895                       opcode << "strt";
896                     } else {
897                       opcode << "str";
898                     }
899                     args << Rt << ", [" << Rn;
900                     if (P == 0 && W == 1) {
901                       args << "], #" << imm32;
902                     } else {
903                       args << ", #" << imm32 << "]";
904                       if (W == 1) {
905                         args << "!";
906                       }
907                     }
908                   }
909                 } else {
910                   // STR Rt, [Rn, Rm, LSL #imm2] - 111 11 000 010 0 nnnn tttt 000000iimmmm
911                   ArmRegister Rn(instr, 16);
912                   ArmRegister Rt(instr, 12);
913                   ArmRegister Rm(instr, 0);
914                   uint32_t imm2 = (instr >> 4) & 3;
915                   opcode << "str.w";
916                   args << Rt << ", [" << Rn << ", " << Rm;
917                   if (imm2 != 0) {
918                     args << ", lsl #" << imm2;
919                   }
920                   args << "]";
921                 }
922               } else if (op3 == 6) {
923                 // STR.W Rt, [Rn, #imm12] - 111 11 000 110 0 nnnn tttt iiiiiiiiiiii
924                 uint32_t imm12 = instr & 0xFFF;
925                 opcode << "str.w";
926                 args << Rt << ", [" << Rn << ", #" << imm12 << "]";
927               }
928               break;
929             }
930           }
931 
932           break;
933         }
934         case 0x03: case 0x0B: case 0x13: case 0x1B: {  // 00xx011
935           // Load halfword
936           // |111|11|10|0 0|00|0|0000|1111|110000|000000|
937           // |5 3|21|09|8 7|65|4|3  0|5  2|10   6|5    0|
938           // |---|--|--|---|--|-|----|----|------|------|
939           // |332|22|22|2 2|22|2|1111|1111|110000|000000|
940           // |1 9|87|65|4 3|21|0|9  6|5  2|10   6|5    0|
941           // |---|--|--|---|--|-|----|----|------|------|
942           // |111|11|00|op3|01|1| Rn | Rt | op4  |      |
943           // |111|11| op2       |    |    | imm12       |
944           uint32_t op3 = (instr >> 23) & 3;
945           ArmRegister Rn(instr, 16);
946           ArmRegister Rt(instr, 12);
947           if (Rt.r != 15) {
948             if (op3 == 1) {
949               // LDRH.W Rt, [Rn, #imm12]       - 111 11 00 01 011 nnnn tttt iiiiiiiiiiii
950               uint32_t imm12 = instr & 0xFFF;
951               opcode << "ldrh.w";
952               args << Rt << ", [" << Rn << ", #" << imm12 << "]";
953               if (Rn.r == 9) {
954                 args << "  ; ";
955                 Thread::DumpThreadOffset(args, imm12, 4);
956               } else if (Rn.r == 15) {
957                 intptr_t lit_adr = reinterpret_cast<intptr_t>(instr_ptr);
958                 lit_adr = RoundDown(lit_adr, 4) + 4 + imm12;
959                 args << "  ; " << reinterpret_cast<void*>(*reinterpret_cast<int32_t*>(lit_adr));
960               }
961             } else if (op3 == 3) {
962               // LDRSH.W Rt, [Rn, #imm12]      - 111 11 00 11 011 nnnn tttt iiiiiiiiiiii
963               uint32_t imm12 = instr & 0xFFF;
964               opcode << "ldrsh.w";
965               args << Rt << ", [" << Rn << ", #" << imm12 << "]";
966               if (Rn.r == 9) {
967                 args << "  ; ";
968                 Thread::DumpThreadOffset(args, imm12, 4);
969               } else if (Rn.r == 15) {
970                 intptr_t lit_adr = reinterpret_cast<intptr_t>(instr_ptr);
971                 lit_adr = RoundDown(lit_adr, 4) + 4 + imm12;
972                 args << "  ; " << reinterpret_cast<void*>(*reinterpret_cast<int32_t*>(lit_adr));
973               }
974             }
975           }
976           break;
977         }
978         case 0x05: case 0x0D: case 0x15: case 0x1D: {  // 00xx101
979           // Load word
980           // |111|11|10|0 0|00|0|0000|1111|110000|000000|
981           // |5 3|21|09|8 7|65|4|3  0|5  2|10   6|5    0|
982           // |---|--|--|---|--|-|----|----|------|------|
983           // |332|22|22|2 2|22|2|1111|1111|110000|000000|
984           // |1 9|87|65|4 3|21|0|9  6|5  2|10   6|5    0|
985           // |---|--|--|---|--|-|----|----|------|------|
986           // |111|11|00|op3|10|1| Rn | Rt | op4  |      |
987           // |111|11| op2       |    |    | imm12       |
988           uint32_t op3 = (instr >> 23) & 3;
989           uint32_t op4 = (instr >> 6) & 0x3F;
990           ArmRegister Rn(instr, 16);
991           ArmRegister Rt(instr, 12);
992           if (op3 == 1 || Rn.r == 15) {
993             // LDR.W Rt, [Rn, #imm12]          - 111 11 00 00 101 nnnn tttt iiiiiiiiiiii
994             // LDR.W Rt, [PC, #imm12]          - 111 11 00 0x 101 1111 tttt iiiiiiiiiiii
995             uint32_t imm12 = instr & 0xFFF;
996             opcode << "ldr.w";
997             args << Rt << ", [" << Rn << ", #" << imm12 << "]";
998             if (Rn.r == 9) {
999               args << "  ; ";
1000               Thread::DumpThreadOffset(args, imm12, 4);
1001             } else if (Rn.r == 15) {
1002               intptr_t lit_adr = reinterpret_cast<intptr_t>(instr_ptr);
1003               lit_adr = RoundDown(lit_adr, 4) + 4 + imm12;
1004               args << "  ; " << reinterpret_cast<void*>(*reinterpret_cast<int32_t*>(lit_adr));
1005             }
1006           } else if (op4 == 0) {
1007             // LDR.W Rt, [Rn, Rm{, LSL #imm2}] - 111 11 00 00 101 nnnn tttt 000000iimmmm
1008             uint32_t imm2 = (instr >> 4) & 0xF;
1009             ArmRegister rm(instr, 0);
1010             opcode << "ldr.w";
1011             args << Rt << ", [" << Rn << ", " << rm;
1012             if (imm2 != 0) {
1013               args << ", lsl #" << imm2;
1014             }
1015             args << "]";
1016           } else {
1017             // LDRT Rt, [Rn, #imm8]            - 111 11 00 00 101 nnnn tttt 1110iiiiiiii
1018             uint32_t imm8 = instr & 0xFF;
1019             opcode << "ldrt";
1020             args << Rt << ", [" << Rn << ", #" << imm8 << "]";
1021           }
1022           break;
1023         }
1024       }
1025     default:
1026       break;
1027   }
1028 
1029   // Apply any IT-block conditions to the opcode if necessary.
1030   if (!it_conditions_.empty()) {
1031     opcode << it_conditions_.back();
1032     it_conditions_.pop_back();
1033   }
1034 
1035   os << StringPrintf("%p: %08x\t%-7s ", instr_ptr, instr, opcode.str().c_str()) << args.str() << '\n';
1036   return 4;
1037 }  // NOLINT(readability/fn_size)
1038 
DumpThumb16(std::ostream & os,const uint8_t * instr_ptr)1039 size_t DisassemblerArm::DumpThumb16(std::ostream& os, const uint8_t* instr_ptr) {
1040   uint16_t instr = ReadU16(instr_ptr);
1041   bool is_32bit = ((instr & 0xF000) == 0xF000) || ((instr & 0xF800) == 0xE800);
1042   if (is_32bit) {
1043     return DumpThumb32(os, instr_ptr);
1044   } else {
1045     std::ostringstream opcode;
1046     std::ostringstream args;
1047     uint16_t opcode1 = instr >> 10;
1048     if (opcode1 < 0x10) {
1049       // shift (immediate), add, subtract, move, and compare
1050       uint16_t opcode2 = instr >> 9;
1051       switch (opcode2) {
1052         case 0x0: case 0x1: case 0x2: case 0x3: case 0x4: case 0x5: case 0x6: case 0x7:
1053         case 0x8: case 0x9: case 0xA: case 0xB: {
1054           // Logical shift left     - 00 000xx iii mmm ddd
1055           // Logical shift right    - 00 001xx iii mmm ddd
1056           // Arithmetic shift right - 00 010xx iii mmm ddd
1057           uint16_t imm5 = (instr >> 6) & 0x1F;
1058           ThumbRegister rm(instr, 3);
1059           ThumbRegister Rd(instr, 0);
1060           if (opcode2 <= 3) {
1061             opcode << "lsls";
1062           } else if (opcode2 <= 7) {
1063             opcode << "lsrs";
1064           } else {
1065             opcode << "asrs";
1066           }
1067           args << Rd << ", " << rm << ", #" << imm5;
1068           break;
1069         }
1070         case 0xC: case 0xD: case 0xE: case 0xF: {
1071           // Add register        - 00 01100 mmm nnn ddd
1072           // Sub register        - 00 01101 mmm nnn ddd
1073           // Add 3-bit immediate - 00 01110 iii nnn ddd
1074           // Sub 3-bit immediate - 00 01111 iii nnn ddd
1075           uint16_t imm3_or_Rm = (instr >> 6) & 7;
1076           ThumbRegister Rn(instr, 3);
1077           ThumbRegister Rd(instr, 0);
1078           if ((opcode2 & 2) != 0 && imm3_or_Rm == 0) {
1079             opcode << "mov";
1080           } else {
1081             if ((opcode2 & 1) == 0) {
1082               opcode << "adds";
1083             } else {
1084               opcode << "subs";
1085             }
1086           }
1087           args << Rd << ", " << Rn;
1088           if ((opcode2 & 2) == 0) {
1089             ArmRegister Rm(imm3_or_Rm);
1090             args << ", " << Rm;
1091           } else if (imm3_or_Rm != 0) {
1092             args << ", #" << imm3_or_Rm;
1093           }
1094           break;
1095         }
1096         case 0x10: case 0x11: case 0x12: case 0x13:
1097         case 0x14: case 0x15: case 0x16: case 0x17:
1098         case 0x18: case 0x19: case 0x1A: case 0x1B:
1099         case 0x1C: case 0x1D: case 0x1E: case 0x1F: {
1100           // MOVS Rd, #imm8 - 00100 ddd iiiiiiii
1101           // CMP  Rn, #imm8 - 00101 nnn iiiiiiii
1102           // ADDS Rn, #imm8 - 00110 nnn iiiiiiii
1103           // SUBS Rn, #imm8 - 00111 nnn iiiiiiii
1104           ThumbRegister Rn(instr, 8);
1105           uint16_t imm8 = instr & 0xFF;
1106           switch (opcode2 >> 2) {
1107             case 4: opcode << "movs"; break;
1108             case 5: opcode << "cmp"; break;
1109             case 6: opcode << "adds"; break;
1110             case 7: opcode << "subs"; break;
1111           }
1112           args << Rn << ", #" << imm8;
1113           break;
1114         }
1115         default:
1116           break;
1117       }
1118     } else if (opcode1 == 0x10) {
1119       // Data-processing
1120       uint16_t opcode2 = (instr >> 6) & 0xF;
1121       ThumbRegister rm(instr, 3);
1122       ThumbRegister rdn(instr, 0);
1123       opcode << kThumbDataProcessingOperations[opcode2];
1124       args << rdn << ", " << rm;
1125     } else if (opcode1 == 0x11) {
1126       // Special data instructions and branch and exchange
1127       uint16_t opcode2 = (instr >> 6) & 0x0F;
1128       switch (opcode2) {
1129         case 0x0: case 0x1: case 0x2: case 0x3: {
1130           // Add low registers  - 010001 0000 xxxxxx
1131           // Add high registers - 010001 0001/001x xxxxxx
1132           uint16_t DN = (instr >> 7) & 1;
1133           ArmRegister rm(instr, 3);
1134           uint16_t Rdn = instr & 7;
1135           ArmRegister DN_Rdn((DN << 3) | Rdn);
1136           opcode << "add";
1137           args << DN_Rdn << ", " << rm;
1138           break;
1139         }
1140         case 0x8: case 0x9: case 0xA: case 0xB: {
1141           // Move low registers  - 010001 1000 xxxxxx
1142           // Move high registers - 010001 1001/101x xxxxxx
1143           uint16_t DN = (instr >> 7) & 1;
1144           ArmRegister rm(instr, 3);
1145           uint16_t Rdn = instr & 7;
1146           ArmRegister DN_Rdn((DN << 3) | Rdn);
1147           opcode << "mov";
1148           args << DN_Rdn << ", " << rm;
1149           break;
1150         }
1151         case 0x5: case 0x6: case 0x7: {
1152           // Compare high registers - 010001 0101/011x xxxxxx
1153           uint16_t N = (instr >> 7) & 1;
1154           ArmRegister rm(instr, 3);
1155           uint16_t Rn = instr & 7;
1156           ArmRegister N_Rn((N << 3) | Rn);
1157           opcode << "cmp";
1158           args << N_Rn << ", " << rm;
1159           break;
1160         }
1161         case 0xC: case 0xD: case 0xE: case 0xF: {
1162           // Branch and exchange           - 010001 110x xxxxxx
1163           // Branch with link and exchange - 010001 111x xxxxxx
1164           ArmRegister rm(instr, 3);
1165           opcode << ((opcode2 & 0x2) == 0 ? "bx" : "blx");
1166           args << rm;
1167           break;
1168         }
1169         default:
1170           break;
1171       }
1172     } else if (opcode1 == 0x12 || opcode1 == 0x13) {  // 01001x
1173       ThumbRegister Rt(instr, 8);
1174       uint16_t imm8 = instr & 0xFF;
1175       opcode << "ldr";
1176       args << Rt << ", [pc, #" << (imm8 << 2) << "]";
1177     } else if ((opcode1 >= 0x14 && opcode1 <= 0x17) ||  // 0101xx
1178                (opcode1 >= 0x18 && opcode1 <= 0x1f) ||  // 011xxx
1179                (opcode1 >= 0x20 && opcode1 <= 0x27)) {  // 100xxx
1180       // Load/store single data item
1181       uint16_t opA = (instr >> 12) & 0xF;
1182       if (opA == 0x5) {
1183         uint16_t opB = (instr >> 9) & 0x7;
1184         ThumbRegister Rm(instr, 6);
1185         ThumbRegister Rn(instr, 3);
1186         ThumbRegister Rt(instr, 0);
1187         switch (opB) {
1188           case 0: opcode << "str"; break;
1189           case 1: opcode << "strh"; break;
1190           case 2: opcode << "strb"; break;
1191           case 3: opcode << "ldrsb"; break;
1192           case 4: opcode << "ldr"; break;
1193           case 5: opcode << "ldrh"; break;
1194           case 6: opcode << "ldrb"; break;
1195           case 7: opcode << "ldrsh"; break;
1196         }
1197         args << Rt << ", [" << Rn << ", " << Rm << "]";
1198       } else if (opA == 9) {
1199         uint16_t opB = (instr >> 11) & 1;
1200         ThumbRegister Rt(instr, 8);
1201         uint16_t imm8 = instr & 0xFF;
1202         opcode << (opB == 0 ? "str" : "ldr");
1203         args << Rt << ", [sp, #" << (imm8 << 2) << "]";
1204       } else {
1205         uint16_t imm5 = (instr >> 6) & 0x1F;
1206         uint16_t opB = (instr >> 11) & 1;
1207         ThumbRegister Rn(instr, 3);
1208         ThumbRegister Rt(instr, 0);
1209         switch (opA) {
1210           case 6:
1211             imm5 <<= 2;
1212             opcode << (opB == 0 ? "str" : "ldr");
1213             break;
1214           case 7:
1215             imm5 <<= 0;
1216             opcode << (opB == 0 ? "strb" : "ldrb");
1217             break;
1218           case 8:
1219             imm5 <<= 1;
1220             opcode << (opB == 0 ? "strh" : "ldrh");
1221             break;
1222         }
1223         args << Rt << ", [" << Rn << ", #" << imm5 << "]";
1224       }
1225     } else if (opcode1 >= 0x34 && opcode1 <= 0x37) {  // 1101xx
1226       int8_t imm8 = instr & 0xFF;
1227       uint32_t cond = (instr >> 8) & 0xF;
1228       opcode << "b";
1229       DumpCond(opcode, cond);
1230       DumpBranchTarget(args, instr_ptr + 4, (imm8 << 1));
1231     } else if ((instr & 0xF800) == 0xA800) {
1232       // Generate SP-relative address
1233       ThumbRegister rd(instr, 8);
1234       int imm8 = instr & 0xFF;
1235       opcode << "add";
1236       args << rd << ", sp, #" << (imm8 << 2);
1237     } else if ((instr & 0xF000) == 0xB000) {
1238       // Miscellaneous 16-bit instructions
1239       uint16_t opcode2 = (instr >> 5) & 0x7F;
1240       switch (opcode2) {
1241         case 0x00: case 0x01: case 0x02: case 0x03: case 0x04: case 0x05: case 0x06: case 0x07: {
1242           // Add immediate to SP        - 1011 00000 ii iiiii
1243           // Subtract immediate from SP - 1011 00001 ii iiiii
1244           int imm7 = instr & 0x7F;
1245           opcode << ((opcode2 & 4) == 0 ? "add" : "sub");
1246           args << "sp, sp, #" << (imm7 << 2);
1247           break;
1248         }
1249         case 0x08: case 0x09: case 0x0A: case 0x0B:  // 0001xxx
1250         case 0x0C: case 0x0D: case 0x0E: case 0x0F:
1251         case 0x18: case 0x19: case 0x1A: case 0x1B:  // 0011xxx
1252         case 0x1C: case 0x1D: case 0x1E: case 0x1F:
1253         case 0x48: case 0x49: case 0x4A: case 0x4B:  // 1001xxx
1254         case 0x4C: case 0x4D: case 0x4E: case 0x4F:
1255         case 0x58: case 0x59: case 0x5A: case 0x5B:  // 1011xxx
1256         case 0x5C: case 0x5D: case 0x5E: case 0x5F: {
1257           // CBNZ, CBZ
1258           uint16_t op = (instr >> 11) & 1;
1259           uint16_t i = (instr >> 9) & 1;
1260           uint16_t imm5 = (instr >> 3) & 0x1F;
1261           ThumbRegister Rn(instr, 0);
1262           opcode << (op != 0 ? "cbnz" : "cbz");
1263           uint32_t imm32 = (i << 6) | (imm5 << 1);
1264           args << Rn << ", ";
1265           DumpBranchTarget(args, instr_ptr + 4, imm32);
1266           break;
1267         }
1268         case 0x78: case 0x79: case 0x7A: case 0x7B:  // 1111xxx
1269         case 0x7C: case 0x7D: case 0x7E: case 0x7F: {
1270           // If-Then, and hints
1271           uint16_t opA = (instr >> 4) & 0xF;
1272           uint16_t opB = instr & 0xF;
1273           if (opB == 0) {
1274             switch (opA) {
1275               case 0: opcode << "nop"; break;
1276               case 1: opcode << "yield"; break;
1277               case 2: opcode << "wfe";  break;
1278               case 3: opcode << "sev"; break;
1279               default: break;
1280             }
1281           } else {
1282             uint32_t first_cond = opA;
1283             uint32_t mask = opB;
1284             opcode << "it";
1285 
1286             // Flesh out the base "it" opcode with the specific collection of 't's and 'e's,
1287             // and store up the actual condition codes we'll want to add to the next few opcodes.
1288             size_t count = 3 - CTZ(mask);
1289             it_conditions_.resize(count + 2);  // Plus the implicit 't', plus the "" for the IT itself.
1290             for (size_t i = 0; i < count; ++i) {
1291               bool positive_cond = ((first_cond & 1) != 0);
1292               bool positive_mask = ((mask & (1 << (3 - i))) != 0);
1293               if (positive_mask == positive_cond) {
1294                 opcode << 't';
1295                 it_conditions_[i] = kConditionCodeNames[first_cond];
1296               } else {
1297                 opcode << 'e';
1298                 it_conditions_[i] = kConditionCodeNames[first_cond ^ 1];
1299               }
1300             }
1301             it_conditions_[count] = kConditionCodeNames[first_cond];  // The implicit 't'.
1302 
1303             it_conditions_[count + 1] = "";  // No condition code for the IT itself...
1304             DumpCond(args, first_cond);  // ...because it's considered an argument.
1305           }
1306           break;
1307         }
1308         default:
1309           break;
1310       }
1311     } else if (((instr & 0xF000) == 0x5000) || ((instr & 0xE000) == 0x6000) ||
1312         ((instr & 0xE000) == 0x8000)) {
1313       // Load/store single data item
1314       uint16_t opA = instr >> 12;
1315       // uint16_t opB = (instr >> 9) & 7;
1316       switch (opA) {
1317         case 0x6: {
1318           // STR Rt, [Rn, #imm] - 01100 iiiii nnn ttt
1319           // LDR Rt, [Rn, #imm] - 01101 iiiii nnn ttt
1320           uint16_t imm5 = (instr >> 6) & 0x1F;
1321           ThumbRegister Rn(instr, 3);
1322           ThumbRegister Rt(instr, 0);
1323           opcode << ((instr & 0x800) == 0 ? "str" : "ldr");
1324           args << Rt << ", [" << Rn << ", #" << (imm5 << 2) << "]";
1325           break;
1326         }
1327         case 0x9: {
1328           // STR Rt, [SP, #imm] - 01100 ttt iiiiiiii
1329           // LDR Rt, [SP, #imm] - 01101 ttt iiiiiiii
1330           uint16_t imm8 = instr & 0xFF;
1331           ThumbRegister Rt(instr, 8);
1332           opcode << ((instr & 0x800) == 0 ? "str" : "ldr");
1333           args << Rt << ", [sp, #" << (imm8 << 2) << "]";
1334           break;
1335         }
1336         default:
1337           break;
1338       }
1339     } else if (opcode1 == 0x38 || opcode1 == 0x39) {
1340       uint16_t imm11 = instr & 0x7FFF;
1341       int32_t imm32 = imm11 << 1;
1342       imm32 = (imm32 << 20) >> 20;  // sign extend 12 bit immediate
1343       opcode << "b";
1344       DumpBranchTarget(args, instr_ptr + 4, imm32);
1345     }
1346 
1347     // Apply any IT-block conditions to the opcode if necessary.
1348     if (!it_conditions_.empty()) {
1349       opcode << it_conditions_.back();
1350       it_conditions_.pop_back();
1351     }
1352 
1353     os << StringPrintf("%p: %04x    \t%-7s ", instr_ptr, instr, opcode.str().c_str()) << args.str() << '\n';
1354   }
1355   return 2;
1356 }
1357 
1358 }  // namespace arm
1359 }  // namespace art
1360