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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_x86.h"
18 
19 #include <inttypes.h>
20 
21 #include <ostream>
22 #include <sstream>
23 
24 #include "android-base/logging.h"
25 #include "android-base/stringprintf.h"
26 
27 using android::base::StringPrintf;
28 
29 namespace art {
30 namespace x86 {
31 
Dump(std::ostream & os,const uint8_t * begin)32 size_t DisassemblerX86::Dump(std::ostream& os, const uint8_t* begin) {
33   return DumpInstruction(os, begin);
34 }
35 
Dump(std::ostream & os,const uint8_t * begin,const uint8_t * end)36 void DisassemblerX86::Dump(std::ostream& os, const uint8_t* begin, const uint8_t* end) {
37   size_t length = 0;
38   for (const uint8_t* cur = begin; cur < end; cur += length) {
39     length = DumpInstruction(os, cur);
40   }
41 }
42 
43 static const char* gReg8Names[]  = {
44   "al", "cl", "dl", "bl", "ah", "ch", "dh", "bh"
45 };
46 static const char* gExtReg8Names[] = {
47   "al", "cl", "dl", "bl", "spl", "bpl", "sil", "dil",
48   "r8l", "r9l", "r10l", "r11l", "r12l", "r13l", "r14l", "r15l"
49 };
50 static const char* gReg16Names[] = {
51   "ax", "cx", "dx", "bx", "sp", "bp", "si", "di",
52   "r8w", "r9w", "r10w", "r11w", "r12w", "r13w", "r14w", "r15w"
53 };
54 static const char* gReg32Names[] = {
55   "eax", "ecx", "edx", "ebx", "esp", "ebp", "esi", "edi",
56   "r8d", "r9d", "r10d", "r11d", "r12d", "r13d", "r14d", "r15d"
57 };
58 static const char* gReg64Names[] = {
59   "rax", "rcx", "rdx", "rbx", "rsp", "rbp", "rsi", "rdi",
60   "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15"
61 };
62 
63 // 64-bit opcode REX modifier.
64 constexpr uint8_t REX_W = 8U /* 0b1000 */;
65 constexpr uint8_t REX_R = 4U /* 0b0100 */;
66 constexpr uint8_t REX_X = 2U /* 0b0010 */;
67 constexpr uint8_t REX_B = 1U /* 0b0001 */;
68 
DumpReg0(std::ostream & os,uint8_t rex,size_t reg,bool byte_operand,uint8_t size_override)69 static void DumpReg0(std::ostream& os, uint8_t rex, size_t reg,
70                      bool byte_operand, uint8_t size_override) {
71   DCHECK_LT(reg, (rex == 0) ? 8u : 16u);
72   bool rex_w = (rex & REX_W) != 0;
73   if (byte_operand) {
74     os << ((rex == 0) ? gReg8Names[reg] : gExtReg8Names[reg]);
75   } else if (rex_w) {
76     os << gReg64Names[reg];
77   } else if (size_override == 0x66) {
78     os << gReg16Names[reg];
79   } else {
80     os << gReg32Names[reg];
81   }
82 }
83 
DumpAnyReg(std::ostream & os,uint8_t rex,size_t reg,bool byte_operand,uint8_t size_override,RegFile reg_file)84 static void DumpAnyReg(std::ostream& os, uint8_t rex, size_t reg,
85                        bool byte_operand, uint8_t size_override, RegFile reg_file) {
86   if (reg_file == GPR) {
87     DumpReg0(os, rex, reg, byte_operand, size_override);
88   } else if (reg_file == SSE) {
89     os << "xmm" << reg;
90   } else {
91     os << "mm" << reg;
92   }
93 }
94 
DumpReg(std::ostream & os,uint8_t rex,uint8_t reg,bool byte_operand,uint8_t size_override,RegFile reg_file)95 static void DumpReg(std::ostream& os, uint8_t rex, uint8_t reg,
96                     bool byte_operand, uint8_t size_override, RegFile reg_file) {
97   bool rex_r = (rex & REX_R) != 0;
98   size_t reg_num = rex_r ? (reg + 8) : reg;
99   DumpAnyReg(os, rex, reg_num, byte_operand, size_override, reg_file);
100 }
101 
DumpRmReg(std::ostream & os,uint8_t rex,uint8_t reg,bool byte_operand,uint8_t size_override,RegFile reg_file)102 static void DumpRmReg(std::ostream& os, uint8_t rex, uint8_t reg,
103                       bool byte_operand, uint8_t size_override, RegFile reg_file) {
104   bool rex_b = (rex & REX_B) != 0;
105   size_t reg_num = rex_b ? (reg + 8) : reg;
106   DumpAnyReg(os, rex, reg_num, byte_operand, size_override, reg_file);
107 }
108 
DumpAddrReg(std::ostream & os,uint8_t rex,uint8_t reg)109 static void DumpAddrReg(std::ostream& os, uint8_t rex, uint8_t reg) {
110   if (rex != 0) {
111     os << gReg64Names[reg];
112   } else {
113     os << gReg32Names[reg];
114   }
115 }
116 
DumpBaseReg(std::ostream & os,uint8_t rex,uint8_t reg)117 static void DumpBaseReg(std::ostream& os, uint8_t rex, uint8_t reg) {
118   bool rex_b = (rex & REX_B) != 0;
119   size_t reg_num = rex_b ? (reg + 8) : reg;
120   DumpAddrReg(os, rex, reg_num);
121 }
122 
DumpOpcodeReg(std::ostream & os,uint8_t rex,uint8_t reg,bool byte_operand,uint8_t size_override)123 static void DumpOpcodeReg(std::ostream& os, uint8_t rex, uint8_t reg,
124                           bool byte_operand, uint8_t size_override) {
125   bool rex_b = (rex & REX_B) != 0;
126   size_t reg_num = rex_b ? (reg + 8) : reg;
127   DumpReg0(os, rex, reg_num, byte_operand, size_override);
128 }
129 
130 enum SegmentPrefix {
131   kCs = 0x2e,
132   kSs = 0x36,
133   kDs = 0x3e,
134   kEs = 0x26,
135   kFs = 0x64,
136   kGs = 0x65,
137 };
138 
DumpSegmentOverride(std::ostream & os,uint8_t segment_prefix)139 static void DumpSegmentOverride(std::ostream& os, uint8_t segment_prefix) {
140   switch (segment_prefix) {
141     case kCs: os << "cs:"; break;
142     case kSs: os << "ss:"; break;
143     case kDs: os << "ds:"; break;
144     case kEs: os << "es:"; break;
145     case kFs: os << "fs:"; break;
146     case kGs: os << "gs:"; break;
147     default: break;
148   }
149 }
150 
151 // Do not inline to avoid Clang stack frame problems. b/18733806
152 NO_INLINE
DumpCodeHex(const uint8_t * begin,const uint8_t * end)153 static std::string DumpCodeHex(const uint8_t* begin, const uint8_t* end) {
154   std::stringstream hex;
155   for (size_t i = 0; begin + i < end; ++i) {
156     hex << StringPrintf("%02X", begin[i]);
157   }
158   return hex.str();
159 }
160 
DumpAddress(uint8_t mod,uint8_t rm,uint8_t rex64,uint8_t rex_w,bool no_ops,bool byte_operand,bool byte_second_operand,uint8_t * prefix,bool load,RegFile src_reg_file,RegFile dst_reg_file,const uint8_t ** instr,uint32_t * address_bits)161 std::string DisassemblerX86::DumpAddress(uint8_t mod, uint8_t rm, uint8_t rex64, uint8_t rex_w,
162                                          bool no_ops, bool byte_operand, bool byte_second_operand,
163                                          uint8_t* prefix, bool load, RegFile src_reg_file,
164                                          RegFile dst_reg_file, const uint8_t** instr,
165                                          uint32_t* address_bits) {
166   std::ostringstream address;
167   if (mod == 0 && rm == 5) {
168     if (!supports_rex_) {  // Absolute address.
169       *address_bits = *reinterpret_cast<const uint32_t*>(*instr);
170       address << StringPrintf("[0x%x]", *address_bits);
171     } else {  // 64-bit RIP relative addressing.
172       address << StringPrintf("[RIP + 0x%x]",  *reinterpret_cast<const uint32_t*>(*instr));
173     }
174     (*instr) += 4;
175   } else if (rm == 4 && mod != 3) {  // SIB
176     uint8_t sib = **instr;
177     (*instr)++;
178     uint8_t scale = (sib >> 6) & 3;
179     uint8_t index = (sib >> 3) & 7;
180     uint8_t base = sib & 7;
181     address << "[";
182 
183     // REX.x is bit 3 of index.
184     if ((rex64 & REX_X) != 0) {
185       index += 8;
186     }
187 
188     // Mod = 0 && base = 5 (ebp): no base (ignores REX.b).
189     bool has_base = false;
190     if (base != 5 || mod != 0) {
191       has_base = true;
192       DumpBaseReg(address, rex64, base);
193     }
194 
195     // Index = 4 (esp/rsp) is disallowed.
196     if (index != 4) {
197       if (has_base) {
198         address << " + ";
199       }
200       DumpAddrReg(address, rex64, index);
201       if (scale != 0) {
202         address << StringPrintf(" * %d", 1 << scale);
203       }
204     }
205 
206     if (mod == 0) {
207       if (base == 5) {
208         if (index != 4) {
209           address << StringPrintf(" + %d", *reinterpret_cast<const int32_t*>(*instr));
210         } else {
211           // 64-bit low 32-bit absolute address, redundant absolute address encoding on 32-bit.
212           *address_bits = *reinterpret_cast<const uint32_t*>(*instr);
213           address << StringPrintf("%d", *address_bits);
214         }
215         (*instr) += 4;
216       }
217     } else if (mod == 1) {
218       address << StringPrintf(" + %d", *reinterpret_cast<const int8_t*>(*instr));
219       (*instr)++;
220     } else if (mod == 2) {
221       address << StringPrintf(" + %d", *reinterpret_cast<const int32_t*>(*instr));
222       (*instr) += 4;
223     }
224     address << "]";
225   } else {
226     if (mod == 3) {
227       if (!no_ops) {
228         DumpRmReg(address, rex_w, rm, byte_operand || byte_second_operand,
229                   prefix[2], load ? src_reg_file : dst_reg_file);
230       }
231     } else {
232       address << "[";
233       DumpBaseReg(address, rex64, rm);
234       if (mod == 1) {
235         address << StringPrintf(" + %d", *reinterpret_cast<const int8_t*>(*instr));
236         (*instr)++;
237       } else if (mod == 2) {
238         address << StringPrintf(" + %d", *reinterpret_cast<const int32_t*>(*instr));
239         (*instr) += 4;
240       }
241       address << "]";
242     }
243   }
244   return address.str();
245 }
246 
DumpNops(std::ostream & os,const uint8_t * instr)247 size_t DisassemblerX86::DumpNops(std::ostream& os, const uint8_t* instr) {
248 static constexpr uint8_t kNops[][10] = {
249       { },
250       { 0x90 },
251       { 0x66, 0x90 },
252       { 0x0f, 0x1f, 0x00 },
253       { 0x0f, 0x1f, 0x40, 0x00 },
254       { 0x0f, 0x1f, 0x44, 0x00, 0x00 },
255       { 0x66, 0x0f, 0x1f, 0x44, 0x00, 0x00 },
256       { 0x0f, 0x1f, 0x80, 0x00, 0x00, 0x00, 0x00 },
257       { 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00 },
258       { 0x66, 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00 },
259       { 0x66, 0x2e, 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00 }
260   };
261 
262   for (size_t i = 1; i < arraysize(kNops); ++i) {
263     if (memcmp(instr, kNops[i], i) == 0) {
264       os << FormatInstructionPointer(instr)
265          << StringPrintf(": %22s    \t       nop \n", DumpCodeHex(instr, instr + i).c_str());
266       return i;
267     }
268   }
269 
270   return 0;
271 }
272 
DumpInstruction(std::ostream & os,const uint8_t * instr)273 size_t DisassemblerX86::DumpInstruction(std::ostream& os, const uint8_t* instr) {
274   size_t nop_size = DumpNops(os, instr);
275   if (nop_size != 0u) {
276     return nop_size;
277   }
278 
279   const uint8_t* begin_instr = instr;
280   bool have_prefixes = true;
281   uint8_t prefix[4] = {0, 0, 0, 0};
282   do {
283     switch (*instr) {
284         // Group 1 - lock and repeat prefixes:
285       case 0xF0:
286       case 0xF2:
287       case 0xF3:
288         prefix[0] = *instr;
289         break;
290         // Group 2 - segment override prefixes:
291       case kCs:
292       case kSs:
293       case kDs:
294       case kEs:
295       case kFs:
296       case kGs:
297         prefix[1] = *instr;
298         break;
299         // Group 3 - operand size override:
300       case 0x66:
301         prefix[2] = *instr;
302         break;
303         // Group 4 - address size override:
304       case 0x67:
305         prefix[3] = *instr;
306         break;
307       default:
308         have_prefixes = false;
309         break;
310     }
311     if (have_prefixes) {
312       instr++;
313     }
314   } while (have_prefixes);
315   uint8_t rex = (supports_rex_ && (*instr >= 0x40) && (*instr <= 0x4F)) ? *instr : 0;
316   if (rex != 0) {
317     instr++;
318   }
319   const char** modrm_opcodes = nullptr;
320   bool has_modrm = false;
321   bool reg_is_opcode = false;
322   size_t immediate_bytes = 0;
323   size_t branch_bytes = 0;
324   std::string opcode_tmp;    // Storage to keep StringPrintf result alive.
325   const char* opcode0 = "";  // Prefix part.
326   const char* opcode1 = "";  // Main opcode.
327   const char* opcode2 = "";  // Sub-opcode. E.g., jump type.
328   const char* opcode3 = "";  // Mod-rm part.
329   const char* opcode4 = "";  // Suffix part.
330   bool store = false;  // stores to memory (ie rm is on the left)
331   bool load = false;  // loads from memory (ie rm is on the right)
332   bool byte_operand = false;  // true when the opcode is dealing with byte operands
333   // true when the source operand is a byte register but the target register isn't
334   // (ie movsxb/movzxb).
335   bool byte_second_operand = false;
336   bool target_specific = false;  // register name depends on target (64 vs 32 bits).
337   bool ax = false;  // implicit use of ax
338   bool cx = false;  // implicit use of cx
339   bool reg_in_opcode = false;  // low 3-bits of opcode encode register parameter
340   bool no_ops = false;
341   RegFile src_reg_file = GPR;
342   RegFile dst_reg_file = GPR;
343   switch (*instr) {
344 #define DISASSEMBLER_ENTRY(opname, \
345                      rm8_r8, rm32_r32, \
346                      r8_rm8, r32_rm32, \
347                      ax8_i8, ax32_i32) \
348   case rm8_r8:   opcode1 = #opname; store = true; has_modrm = true; byte_operand = true; break; \
349   case rm32_r32: opcode1 = #opname; store = true; has_modrm = true; break; \
350   case r8_rm8:   opcode1 = #opname; load = true; has_modrm = true; byte_operand = true; break; \
351   case r32_rm32: opcode1 = #opname; load = true; has_modrm = true; break; \
352   case ax8_i8:   opcode1 = #opname; ax = true; immediate_bytes = 1; byte_operand = true; break; \
353   case ax32_i32: opcode1 = #opname; ax = true; immediate_bytes = 4; break;
354 
355 DISASSEMBLER_ENTRY(add,
356   0x00 /* RegMem8/Reg8 */,     0x01 /* RegMem32/Reg32 */,
357   0x02 /* Reg8/RegMem8 */,     0x03 /* Reg32/RegMem32 */,
358   0x04 /* Rax8/imm8 opcode */, 0x05 /* Rax32/imm32 */)
359 DISASSEMBLER_ENTRY(or,
360   0x08 /* RegMem8/Reg8 */,     0x09 /* RegMem32/Reg32 */,
361   0x0A /* Reg8/RegMem8 */,     0x0B /* Reg32/RegMem32 */,
362   0x0C /* Rax8/imm8 opcode */, 0x0D /* Rax32/imm32 */)
363 DISASSEMBLER_ENTRY(adc,
364   0x10 /* RegMem8/Reg8 */,     0x11 /* RegMem32/Reg32 */,
365   0x12 /* Reg8/RegMem8 */,     0x13 /* Reg32/RegMem32 */,
366   0x14 /* Rax8/imm8 opcode */, 0x15 /* Rax32/imm32 */)
367 DISASSEMBLER_ENTRY(sbb,
368   0x18 /* RegMem8/Reg8 */,     0x19 /* RegMem32/Reg32 */,
369   0x1A /* Reg8/RegMem8 */,     0x1B /* Reg32/RegMem32 */,
370   0x1C /* Rax8/imm8 opcode */, 0x1D /* Rax32/imm32 */)
371 DISASSEMBLER_ENTRY(and,
372   0x20 /* RegMem8/Reg8 */,     0x21 /* RegMem32/Reg32 */,
373   0x22 /* Reg8/RegMem8 */,     0x23 /* Reg32/RegMem32 */,
374   0x24 /* Rax8/imm8 opcode */, 0x25 /* Rax32/imm32 */)
375 DISASSEMBLER_ENTRY(sub,
376   0x28 /* RegMem8/Reg8 */,     0x29 /* RegMem32/Reg32 */,
377   0x2A /* Reg8/RegMem8 */,     0x2B /* Reg32/RegMem32 */,
378   0x2C /* Rax8/imm8 opcode */, 0x2D /* Rax32/imm32 */)
379 DISASSEMBLER_ENTRY(xor,
380   0x30 /* RegMem8/Reg8 */,     0x31 /* RegMem32/Reg32 */,
381   0x32 /* Reg8/RegMem8 */,     0x33 /* Reg32/RegMem32 */,
382   0x34 /* Rax8/imm8 opcode */, 0x35 /* Rax32/imm32 */)
383 DISASSEMBLER_ENTRY(cmp,
384   0x38 /* RegMem8/Reg8 */,     0x39 /* RegMem32/Reg32 */,
385   0x3A /* Reg8/RegMem8 */,     0x3B /* Reg32/RegMem32 */,
386   0x3C /* Rax8/imm8 opcode */, 0x3D /* Rax32/imm32 */)
387 
388 #undef DISASSEMBLER_ENTRY
389   case 0x50: case 0x51: case 0x52: case 0x53: case 0x54: case 0x55: case 0x56: case 0x57:
390     opcode1 = "push";
391     reg_in_opcode = true;
392     target_specific = true;
393     break;
394   case 0x58: case 0x59: case 0x5A: case 0x5B: case 0x5C: case 0x5D: case 0x5E: case 0x5F:
395     opcode1 = "pop";
396     reg_in_opcode = true;
397     target_specific = true;
398     break;
399   case 0x63:
400     if ((rex & REX_W) != 0) {
401       opcode1 = "movsxd";
402       has_modrm = true;
403       load = true;
404     } else {
405       // In 32-bit mode (!supports_rex_) this is ARPL, with no REX prefix the functionality is the
406       // same as 'mov' but the use of the instruction is discouraged.
407       opcode_tmp = StringPrintf("unknown opcode '%02X'", *instr);
408       opcode1 = opcode_tmp.c_str();
409     }
410     break;
411   case 0x68: opcode1 = "push"; immediate_bytes = 4; break;
412   case 0x69: opcode1 = "imul"; load = true; has_modrm = true; immediate_bytes = 4; break;
413   case 0x6A: opcode1 = "push"; immediate_bytes = 1; break;
414   case 0x6B: opcode1 = "imul"; load = true; has_modrm = true; immediate_bytes = 1; break;
415   case 0x70: case 0x71: case 0x72: case 0x73: case 0x74: case 0x75: case 0x76: case 0x77:
416   case 0x78: case 0x79: case 0x7A: case 0x7B: case 0x7C: case 0x7D: case 0x7E: case 0x7F:
417     static const char* condition_codes[] =
418     {"o", "no", "b/nae/c", "nb/ae/nc", "z/eq",  "nz/ne", "be/na", "nbe/a",
419      "s", "ns", "p/pe",    "np/po",    "l/nge", "nl/ge", "le/ng", "nle/g"
420     };
421     opcode1 = "j";
422     opcode2 = condition_codes[*instr & 0xF];
423     branch_bytes = 1;
424     break;
425   case 0x86: case 0x87:
426     opcode1 = "xchg";
427     store = true;
428     has_modrm = true;
429     byte_operand = (*instr == 0x86);
430     break;
431   case 0x88: opcode1 = "mov"; store = true; has_modrm = true; byte_operand = true; break;
432   case 0x89: opcode1 = "mov"; store = true; has_modrm = true; break;
433   case 0x8A: opcode1 = "mov"; load = true; has_modrm = true; byte_operand = true; break;
434   case 0x8B: opcode1 = "mov"; load = true; has_modrm = true; break;
435   case 0x9D: opcode1 = "popf"; break;
436 
437   case 0x0F:  // 2 byte extended opcode
438     instr++;
439     switch (*instr) {
440       case 0x10: case 0x11:
441         if (prefix[0] == 0xF2) {
442           opcode1 = "movsd";
443           prefix[0] = 0;  // clear prefix now it's served its purpose as part of the opcode
444         } else if (prefix[0] == 0xF3) {
445           opcode1 = "movss";
446           prefix[0] = 0;  // clear prefix now it's served its purpose as part of the opcode
447         } else if (prefix[2] == 0x66) {
448           opcode1 = "movupd";
449           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
450         } else {
451           opcode1 = "movups";
452         }
453         has_modrm = true;
454         src_reg_file = dst_reg_file = SSE;
455         load = *instr == 0x10;
456         store = !load;
457         break;
458       case 0x12: case 0x13:
459         if (prefix[2] == 0x66) {
460           opcode1 = "movlpd";
461           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
462         } else if (prefix[0] == 0) {
463           opcode1 = "movlps";
464         }
465         has_modrm = true;
466         src_reg_file = dst_reg_file = SSE;
467         load = *instr == 0x12;
468         store = !load;
469         break;
470       case 0x16: case 0x17:
471         if (prefix[2] == 0x66) {
472           opcode1 = "movhpd";
473           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
474         } else if (prefix[0] == 0) {
475           opcode1 = "movhps";
476         }
477         has_modrm = true;
478         src_reg_file = dst_reg_file = SSE;
479         load = *instr == 0x16;
480         store = !load;
481         break;
482       case 0x28: case 0x29:
483         if (prefix[2] == 0x66) {
484           opcode1 = "movapd";
485           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
486         } else if (prefix[0] == 0) {
487           opcode1 = "movaps";
488         }
489         has_modrm = true;
490         src_reg_file = dst_reg_file = SSE;
491         load = *instr == 0x28;
492         store = !load;
493         break;
494       case 0x2A:
495         if (prefix[2] == 0x66) {
496           opcode1 = "cvtpi2pd";
497           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
498         } else if (prefix[0] == 0xF2) {
499           opcode1 = "cvtsi2sd";
500           prefix[0] = 0;  // clear prefix now it's served its purpose as part of the opcode
501         } else if (prefix[0] == 0xF3) {
502           opcode1 = "cvtsi2ss";
503           prefix[0] = 0;  // clear prefix now it's served its purpose as part of the opcode
504         } else {
505           opcode1 = "cvtpi2ps";
506         }
507         load = true;
508         has_modrm = true;
509         dst_reg_file = SSE;
510         break;
511       case 0x2C:
512         if (prefix[2] == 0x66) {
513           opcode1 = "cvttpd2pi";
514           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
515         } else if (prefix[0] == 0xF2) {
516           opcode1 = "cvttsd2si";
517           prefix[0] = 0;  // clear prefix now it's served its purpose as part of the opcode
518         } else if (prefix[0] == 0xF3) {
519           opcode1 = "cvttss2si";
520           prefix[0] = 0;  // clear prefix now it's served its purpose as part of the opcode
521         } else {
522           opcode1 = "cvttps2pi";
523         }
524         load = true;
525         has_modrm = true;
526         src_reg_file = SSE;
527         break;
528       case 0x2D:
529         if (prefix[2] == 0x66) {
530           opcode1 = "cvtpd2pi";
531           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
532         } else if (prefix[0] == 0xF2) {
533           opcode1 = "cvtsd2si";
534           prefix[0] = 0;  // clear prefix now it's served its purpose as part of the opcode
535         } else if (prefix[0] == 0xF3) {
536           opcode1 = "cvtss2si";
537           prefix[0] = 0;  // clear prefix now it's served its purpose as part of the opcode
538         } else {
539           opcode1 = "cvtps2pi";
540         }
541         load = true;
542         has_modrm = true;
543         src_reg_file = SSE;
544         break;
545       case 0x2E:
546         opcode0 = "u";
547         FALLTHROUGH_INTENDED;
548       case 0x2F:
549         if (prefix[2] == 0x66) {
550           opcode1 = "comisd";
551           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
552         } else {
553           opcode1 = "comiss";
554         }
555         has_modrm = true;
556         load = true;
557         src_reg_file = dst_reg_file = SSE;
558         break;
559       case 0x38:  // 3 byte extended opcode
560         instr++;
561         if (prefix[2] == 0x66) {
562           switch (*instr) {
563             case 0x01:
564               opcode1 = "phaddw";
565               prefix[2] = 0;
566               has_modrm = true;
567               load = true;
568               src_reg_file = dst_reg_file = SSE;
569               break;
570             case 0x02:
571               opcode1 = "phaddd";
572               prefix[2] = 0;
573               has_modrm = true;
574               load = true;
575               src_reg_file = dst_reg_file = SSE;
576               break;
577             case 0x29:
578               opcode1 = "pcmpeqq";
579               prefix[2] = 0;
580               has_modrm = true;
581               load = true;
582               src_reg_file = dst_reg_file = SSE;
583               break;
584             case 0x37:
585               opcode1 = "pcmpgtq";
586               prefix[2] = 0;
587               has_modrm = true;
588               load = true;
589               src_reg_file = dst_reg_file = SSE;
590               break;
591             case 0x38:
592               opcode1 = "pminsb";
593               prefix[2] = 0;
594               has_modrm = true;
595               load = true;
596               src_reg_file = dst_reg_file = SSE;
597               break;
598             case 0x39:
599               opcode1 = "pminsd";
600               prefix[2] = 0;
601               has_modrm = true;
602               load = true;
603               src_reg_file = dst_reg_file = SSE;
604               break;
605             case 0x3A:
606               opcode1 = "pminuw";
607               prefix[2] = 0;
608               has_modrm = true;
609               load = true;
610               src_reg_file = dst_reg_file = SSE;
611               break;
612             case 0x3B:
613               opcode1 = "pminud";
614               prefix[2] = 0;
615               has_modrm = true;
616               load = true;
617               src_reg_file = dst_reg_file = SSE;
618               break;
619             case 0x3C:
620               opcode1 = "pmaxsb";
621               prefix[2] = 0;
622               has_modrm = true;
623               load = true;
624               src_reg_file = dst_reg_file = SSE;
625               break;
626             case 0x3D:
627               opcode1 = "pmaxsd";
628               prefix[2] = 0;
629               has_modrm = true;
630               load = true;
631               src_reg_file = dst_reg_file = SSE;
632               break;
633             case 0x3E:
634               opcode1 = "pmaxuw";
635               prefix[2] = 0;
636               has_modrm = true;
637               load = true;
638               src_reg_file = dst_reg_file = SSE;
639               break;
640             case 0x3F:
641               opcode1 = "pmaxud";
642               prefix[2] = 0;
643               has_modrm = true;
644               load = true;
645               src_reg_file = dst_reg_file = SSE;
646               break;
647             case 0x40:
648               opcode1 = "pmulld";
649               prefix[2] = 0;
650               has_modrm = true;
651               load = true;
652               src_reg_file = dst_reg_file = SSE;
653               break;
654             default:
655               opcode_tmp = StringPrintf("unknown opcode '0F 38 %02X'", *instr);
656               opcode1 = opcode_tmp.c_str();
657           }
658         } else {
659           opcode_tmp = StringPrintf("unknown opcode '0F 38 %02X'", *instr);
660           opcode1 = opcode_tmp.c_str();
661         }
662         break;
663       case 0x3A:  // 3 byte extended opcode
664         instr++;
665         if (prefix[2] == 0x66) {
666           switch (*instr) {
667             case 0x0A:
668               opcode1 = "roundss";
669               prefix[2] = 0;
670               has_modrm = true;
671               load = true;
672               src_reg_file = SSE;
673               dst_reg_file = SSE;
674               immediate_bytes = 1;
675               break;
676             case 0x0B:
677               opcode1 = "roundsd";
678               prefix[2] = 0;
679               has_modrm = true;
680               load = true;
681               src_reg_file = SSE;
682               dst_reg_file = SSE;
683               immediate_bytes = 1;
684               break;
685             case 0x14:
686               opcode1 = "pextrb";
687               prefix[2] = 0;
688               has_modrm = true;
689               store = true;
690               src_reg_file = SSE;
691               immediate_bytes = 1;
692               break;
693           case 0x15:
694               opcode1 = "pextrw";
695               prefix[2] = 0;
696               has_modrm = true;
697               store = true;
698               src_reg_file = SSE;
699               immediate_bytes = 1;
700               break;
701             case 0x16:
702               opcode1 = "pextrd";
703               prefix[2] = 0;
704               has_modrm = true;
705               store = true;
706               src_reg_file = SSE;
707               immediate_bytes = 1;
708               break;
709             default:
710               opcode_tmp = StringPrintf("unknown opcode '0F 3A %02X'", *instr);
711               opcode1 = opcode_tmp.c_str();
712           }
713         } else {
714           opcode_tmp = StringPrintf("unknown opcode '0F 3A %02X'", *instr);
715           opcode1 = opcode_tmp.c_str();
716         }
717         break;
718       case 0x40: case 0x41: case 0x42: case 0x43: case 0x44: case 0x45: case 0x46: case 0x47:
719       case 0x48: case 0x49: case 0x4A: case 0x4B: case 0x4C: case 0x4D: case 0x4E: case 0x4F:
720         opcode1 = "cmov";
721         opcode2 = condition_codes[*instr & 0xF];
722         has_modrm = true;
723         load = true;
724         break;
725       case 0x50: case 0x51: case 0x52: case 0x53: case 0x54: case 0x55: case 0x56: case 0x57:
726       case 0x58: case 0x59: case 0x5C: case 0x5D: case 0x5E: case 0x5F: {
727         switch (*instr) {
728           case 0x50: opcode1 = "movmsk"; break;
729           case 0x51: opcode1 = "sqrt"; break;
730           case 0x52: opcode1 = "rsqrt"; break;
731           case 0x53: opcode1 = "rcp"; break;
732           case 0x54: opcode1 = "and"; break;
733           case 0x55: opcode1 = "andn"; break;
734           case 0x56: opcode1 = "or"; break;
735           case 0x57: opcode1 = "xor"; break;
736           case 0x58: opcode1 = "add"; break;
737           case 0x59: opcode1 = "mul"; break;
738           case 0x5C: opcode1 = "sub"; break;
739           case 0x5D: opcode1 = "min"; break;
740           case 0x5E: opcode1 = "div"; break;
741           case 0x5F: opcode1 = "max"; break;
742           default: LOG(FATAL) << "Unreachable"; UNREACHABLE();
743         }
744         if (prefix[2] == 0x66) {
745           opcode2 = "pd";
746           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
747         } else if (prefix[0] == 0xF2) {
748           opcode2 = "sd";
749           prefix[0] = 0;  // clear prefix now it's served its purpose as part of the opcode
750         } else if (prefix[0] == 0xF3) {
751           opcode2 = "ss";
752           prefix[0] = 0;  // clear prefix now it's served its purpose as part of the opcode
753         } else {
754           opcode2 = "ps";
755         }
756         load = true;
757         has_modrm = true;
758         src_reg_file = dst_reg_file = SSE;
759         break;
760       }
761       case 0x5A:
762         if (prefix[2] == 0x66) {
763           opcode1 = "cvtpd2ps";
764           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
765         } else if (prefix[0] == 0xF2) {
766           opcode1 = "cvtsd2ss";
767           prefix[0] = 0;  // clear prefix now it's served its purpose as part of the opcode
768         } else if (prefix[0] == 0xF3) {
769           opcode1 = "cvtss2sd";
770           prefix[0] = 0;  // clear prefix now it's served its purpose as part of the opcode
771         } else {
772           opcode1 = "cvtps2pd";
773         }
774         load = true;
775         has_modrm = true;
776         src_reg_file = dst_reg_file = SSE;
777         break;
778       case 0x5B:
779         if (prefix[2] == 0x66) {
780           opcode1 = "cvtps2dq";
781           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
782         } else if (prefix[0] == 0xF2) {
783           opcode1 = "bad opcode F2 0F 5B";
784         } else if (prefix[0] == 0xF3) {
785           opcode1 = "cvttps2dq";
786           prefix[0] = 0;  // clear prefix now it's served its purpose as part of the opcode
787         } else {
788           opcode1 = "cvtdq2ps";
789         }
790         load = true;
791         has_modrm = true;
792         src_reg_file = dst_reg_file = SSE;
793         break;
794       case 0x60: case 0x61: case 0x62: case 0x6C:
795         if (prefix[2] == 0x66) {
796           src_reg_file = dst_reg_file = SSE;
797           prefix[2] = 0;  // Clear prefix now. It has served its purpose as part of the opcode.
798         } else {
799           src_reg_file = dst_reg_file = MMX;
800         }
801         switch (*instr) {
802           case 0x60: opcode1 = "punpcklbw"; break;
803           case 0x61: opcode1 = "punpcklwd"; break;
804           case 0x62: opcode1 = "punpckldq"; break;
805           case 0x6c: opcode1 = "punpcklqdq"; break;
806         }
807         load = true;
808         has_modrm = true;
809         break;
810       case 0x64:
811       case 0x65:
812       case 0x66:
813         if (prefix[2] == 0x66) {
814           src_reg_file = dst_reg_file = SSE;
815           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
816         } else {
817           src_reg_file = dst_reg_file = MMX;
818         }
819         switch (*instr) {
820           case 0x64: opcode1 = "pcmpgtb"; break;
821           case 0x65: opcode1 = "pcmpgtw"; break;
822           case 0x66: opcode1 = "pcmpgtd"; break;
823         }
824         prefix[2] = 0;
825         has_modrm = true;
826         load = true;
827         break;
828       case 0x6E:
829         if (prefix[2] == 0x66) {
830           dst_reg_file = SSE;
831           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
832         } else {
833           dst_reg_file = MMX;
834         }
835         opcode1 = "movd";
836         load = true;
837         has_modrm = true;
838         break;
839       case 0x6F:
840         if (prefix[2] == 0x66) {
841           src_reg_file = dst_reg_file = SSE;
842           opcode1 = "movdqa";
843           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
844         } else if (prefix[0] == 0xF3) {
845           src_reg_file = dst_reg_file = SSE;
846           opcode1 = "movdqu";
847           prefix[0] = 0;  // clear prefix now it's served its purpose as part of the opcode
848         } else {
849           dst_reg_file = MMX;
850           opcode1 = "movq";
851         }
852         load = true;
853         has_modrm = true;
854         break;
855       case 0x70:
856         if (prefix[2] == 0x66) {
857           opcode1 = "pshufd";
858           prefix[2] = 0;
859           has_modrm = true;
860           store = true;
861           src_reg_file = dst_reg_file = SSE;
862           immediate_bytes = 1;
863         } else if (prefix[0] == 0xF2) {
864           opcode1 = "pshuflw";
865           prefix[0] = 0;
866           has_modrm = true;
867           store = true;
868           src_reg_file = dst_reg_file = SSE;
869           immediate_bytes = 1;
870         } else {
871           opcode_tmp = StringPrintf("unknown opcode '0F %02X'", *instr);
872           opcode1 = opcode_tmp.c_str();
873         }
874         break;
875       case 0x71:
876         if (prefix[2] == 0x66) {
877           dst_reg_file = SSE;
878           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
879         } else {
880           dst_reg_file = MMX;
881         }
882         static const char* x71_opcodes[] = {
883             "unknown-71", "unknown-71", "psrlw", "unknown-71",
884             "psraw",      "unknown-71", "psllw", "unknown-71"};
885         modrm_opcodes = x71_opcodes;
886         reg_is_opcode = true;
887         has_modrm = true;
888         store = true;
889         immediate_bytes = 1;
890         break;
891       case 0x72:
892         if (prefix[2] == 0x66) {
893           dst_reg_file = SSE;
894           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
895         } else {
896           dst_reg_file = MMX;
897         }
898         static const char* x72_opcodes[] = {
899             "unknown-72", "unknown-72", "psrld", "unknown-72",
900             "psrad",      "unknown-72", "pslld", "unknown-72"};
901         modrm_opcodes = x72_opcodes;
902         reg_is_opcode = true;
903         has_modrm = true;
904         store = true;
905         immediate_bytes = 1;
906         break;
907       case 0x73:
908         if (prefix[2] == 0x66) {
909           dst_reg_file = SSE;
910           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
911         } else {
912           dst_reg_file = MMX;
913         }
914         static const char* x73_opcodes[] = {
915             "unknown-73", "unknown-73", "psrlq", "psrldq",
916             "unknown-73", "unknown-73", "psllq", "unknown-73"};
917         modrm_opcodes = x73_opcodes;
918         reg_is_opcode = true;
919         has_modrm = true;
920         store = true;
921         immediate_bytes = 1;
922         break;
923       case 0x74:
924       case 0x75:
925       case 0x76:
926         if (prefix[2] == 0x66) {
927           src_reg_file = dst_reg_file = SSE;
928           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
929         } else {
930           src_reg_file = dst_reg_file = MMX;
931         }
932         switch (*instr) {
933           case 0x74: opcode1 = "pcmpeqb"; break;
934           case 0x75: opcode1 = "pcmpeqw"; break;
935           case 0x76: opcode1 = "pcmpeqd"; break;
936         }
937         prefix[2] = 0;
938         has_modrm = true;
939         load = true;
940         break;
941       case 0x7C:
942         if (prefix[0] == 0xF2) {
943           opcode1 = "haddps";
944           prefix[0] = 0;  // clear prefix now it's served its purpose as part of the opcode
945         } else if (prefix[2] == 0x66) {
946           opcode1 = "haddpd";
947           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
948         } else {
949           opcode_tmp = StringPrintf("unknown opcode '0F %02X'", *instr);
950           opcode1 = opcode_tmp.c_str();
951           break;
952         }
953         src_reg_file = dst_reg_file = SSE;
954         has_modrm = true;
955         load = true;
956         break;
957       case 0x7E:
958         if (prefix[2] == 0x66) {
959           src_reg_file = SSE;
960           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
961         } else {
962           src_reg_file = MMX;
963         }
964         opcode1 = "movd";
965         has_modrm = true;
966         store = true;
967         break;
968       case 0x7F:
969         if (prefix[2] == 0x66) {
970           src_reg_file = dst_reg_file = SSE;
971           opcode1 = "movdqa";
972           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
973         } else if (prefix[0] == 0xF3) {
974           src_reg_file = dst_reg_file = SSE;
975           opcode1 = "movdqu";
976           prefix[0] = 0;  // clear prefix now it's served its purpose as part of the opcode
977         } else {
978           dst_reg_file = MMX;
979           opcode1 = "movq";
980         }
981         store = true;
982         has_modrm = true;
983         break;
984       case 0x80: case 0x81: case 0x82: case 0x83: case 0x84: case 0x85: case 0x86: case 0x87:
985       case 0x88: case 0x89: case 0x8A: case 0x8B: case 0x8C: case 0x8D: case 0x8E: case 0x8F:
986         opcode1 = "j";
987         opcode2 = condition_codes[*instr & 0xF];
988         branch_bytes = 4;
989         break;
990       case 0x90: case 0x91: case 0x92: case 0x93: case 0x94: case 0x95: case 0x96: case 0x97:
991       case 0x98: case 0x99: case 0x9A: case 0x9B: case 0x9C: case 0x9D: case 0x9E: case 0x9F:
992         opcode1 = "set";
993         opcode2 = condition_codes[*instr & 0xF];
994         modrm_opcodes = nullptr;
995         reg_is_opcode = true;
996         has_modrm = true;
997         store = true;
998         break;
999       case 0xA4:
1000         opcode1 = "shld";
1001         has_modrm = true;
1002         load = true;
1003         immediate_bytes = 1;
1004         break;
1005       case 0xA5:
1006         opcode1 = "shld";
1007         has_modrm = true;
1008         load = true;
1009         cx = true;
1010         break;
1011       case 0xAC:
1012         opcode1 = "shrd";
1013         has_modrm = true;
1014         load = true;
1015         immediate_bytes = 1;
1016         break;
1017       case 0xAD:
1018         opcode1 = "shrd";
1019         has_modrm = true;
1020         load = true;
1021         cx = true;
1022         break;
1023       case 0xAE:
1024         if (prefix[0] == 0xF3) {
1025           prefix[0] = 0;  // clear prefix now it's served its purpose as part of the opcode
1026           static const char* xAE_opcodes[] = {
1027               "rdfsbase",   "rdgsbase",   "wrfsbase",   "wrgsbase",
1028               "unknown-AE", "unknown-AE", "unknown-AE", "unknown-AE"};
1029           modrm_opcodes = xAE_opcodes;
1030           reg_is_opcode = true;
1031           has_modrm = true;
1032           uint8_t reg_or_opcode = (instr[1] >> 3) & 7;
1033           switch (reg_or_opcode) {
1034             case 0:
1035               prefix[1] = kFs;
1036               load = true;
1037               break;
1038             case 1:
1039               prefix[1] = kGs;
1040               load = true;
1041               break;
1042             case 2:
1043               prefix[1] = kFs;
1044               store = true;
1045               break;
1046             case 3:
1047               prefix[1] = kGs;
1048               store = true;
1049               break;
1050             default:
1051               load = true;
1052               break;
1053           }
1054         } else {
1055           static const char* xAE_opcodes[] = {
1056               "unknown-AE", "unknown-AE", "unknown-AE", "unknown-AE",
1057               "unknown-AE", "lfence",     "mfence",     "sfence"};
1058           modrm_opcodes = xAE_opcodes;
1059           reg_is_opcode = true;
1060           has_modrm = true;
1061           load = true;
1062           no_ops = true;
1063         }
1064         break;
1065       case 0xAF:
1066         opcode1 = "imul";
1067         has_modrm = true;
1068         load = true;
1069         break;
1070       case 0xB1:
1071         opcode1 = "cmpxchg";
1072         has_modrm = true;
1073         store = true;
1074         break;
1075       case 0xB6:
1076         opcode1 = "movzxb";
1077         has_modrm = true;
1078         load = true;
1079         byte_second_operand = true;
1080         break;
1081       case 0xB7:
1082         opcode1 = "movzxw";
1083         has_modrm = true;
1084         load = true;
1085         break;
1086       case 0xBC:
1087         opcode1 = "bsf";
1088         has_modrm = true;
1089         load = true;
1090         break;
1091       case 0xBD:
1092         opcode1 = "bsr";
1093         has_modrm = true;
1094         load = true;
1095         break;
1096       case 0xB8:
1097         opcode1 = "popcnt";
1098         has_modrm = true;
1099         load = true;
1100         break;
1101       case 0xBE:
1102         opcode1 = "movsxb";
1103         has_modrm = true;
1104         load = true;
1105         byte_second_operand = true;
1106         rex |= (rex == 0 ? 0 : REX_W);
1107         break;
1108       case 0xBF:
1109         opcode1 = "movsxw";
1110         has_modrm = true;
1111         load = true;
1112         break;
1113       case 0xC3:
1114         opcode1 = "movnti";
1115         store = true;
1116         has_modrm = true;
1117         break;
1118       case 0xC5:
1119         if (prefix[2] == 0x66) {
1120           opcode1 = "pextrw";
1121           prefix[2] = 0;
1122           has_modrm = true;
1123           load = true;
1124           src_reg_file = SSE;
1125           immediate_bytes = 1;
1126         } else {
1127           opcode_tmp = StringPrintf("unknown opcode '0F %02X'", *instr);
1128           opcode1 = opcode_tmp.c_str();
1129         }
1130         break;
1131       case 0xC6:
1132         if (prefix[2] == 0x66) {
1133           opcode1 = "shufpd";
1134           prefix[2] = 0;
1135         } else {
1136           opcode1 = "shufps";
1137         }
1138         has_modrm = true;
1139         store = true;
1140         src_reg_file = dst_reg_file = SSE;
1141         immediate_bytes = 1;
1142         break;
1143       case 0xC7:
1144         static const char* x0FxC7_opcodes[] = {
1145             "unknown-0f-c7", "cmpxchg8b",     "unknown-0f-c7", "unknown-0f-c7",
1146             "unknown-0f-c7", "unknown-0f-c7", "unknown-0f-c7", "unknown-0f-c7"};
1147         modrm_opcodes = x0FxC7_opcodes;
1148         has_modrm = true;
1149         reg_is_opcode = true;
1150         store = true;
1151         break;
1152       case 0xC8: case 0xC9: case 0xCA: case 0xCB: case 0xCC: case 0xCD: case 0xCE: case 0xCF:
1153         opcode1 = "bswap";
1154         reg_in_opcode = true;
1155         break;
1156       case 0xD4:
1157         if (prefix[2] == 0x66) {
1158           src_reg_file = dst_reg_file = SSE;
1159           prefix[2] = 0;
1160         } else {
1161           src_reg_file = dst_reg_file = MMX;
1162         }
1163         opcode1 = "paddq";
1164         prefix[2] = 0;
1165         has_modrm = true;
1166         load = true;
1167         break;
1168       case 0xDB:
1169         if (prefix[2] == 0x66) {
1170           src_reg_file = dst_reg_file = SSE;
1171           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
1172         } else {
1173           src_reg_file = dst_reg_file = MMX;
1174         }
1175         opcode1 = "pand";
1176         prefix[2] = 0;
1177         has_modrm = true;
1178         load = true;
1179         break;
1180       case 0xD5:
1181         if (prefix[2] == 0x66) {
1182           opcode1 = "pmullw";
1183           prefix[2] = 0;
1184           has_modrm = true;
1185           load = true;
1186           src_reg_file = dst_reg_file = SSE;
1187         } else {
1188           opcode_tmp = StringPrintf("unknown opcode '0F %02X'", *instr);
1189           opcode1 = opcode_tmp.c_str();
1190         }
1191         break;
1192       case 0xDA:
1193       case 0xDE:
1194       case 0xE0:
1195       case 0xE3:
1196       case 0xEA:
1197       case 0xEE:
1198         if (prefix[2] == 0x66) {
1199           src_reg_file = dst_reg_file = SSE;
1200           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
1201         } else {
1202           src_reg_file = dst_reg_file = MMX;
1203         }
1204         switch (*instr) {
1205           case 0xDA: opcode1 = "pminub"; break;
1206           case 0xDE: opcode1 = "pmaxub"; break;
1207           case 0xE0: opcode1 = "pavgb"; break;
1208           case 0xE3: opcode1 = "pavgw"; break;
1209           case 0xEA: opcode1 = "pminsw"; break;
1210           case 0xEE: opcode1 = "pmaxsw"; break;
1211         }
1212         prefix[2] = 0;
1213         has_modrm = true;
1214         load = true;
1215         break;
1216       case 0xEB:
1217         if (prefix[2] == 0x66) {
1218           src_reg_file = dst_reg_file = SSE;
1219           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
1220         } else {
1221           src_reg_file = dst_reg_file = MMX;
1222         }
1223         opcode1 = "por";
1224         prefix[2] = 0;
1225         has_modrm = true;
1226         load = true;
1227         break;
1228       case 0xEF:
1229         if (prefix[2] == 0x66) {
1230           src_reg_file = dst_reg_file = SSE;
1231           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
1232         } else {
1233           src_reg_file = dst_reg_file = MMX;
1234         }
1235         opcode1 = "pxor";
1236         prefix[2] = 0;
1237         has_modrm = true;
1238         load = true;
1239         break;
1240       case 0xF4:
1241       case 0xF6:
1242       case 0xF8:
1243       case 0xF9:
1244       case 0xFA:
1245       case 0xFB:
1246       case 0xFC:
1247       case 0xFD:
1248       case 0xFE:
1249         if (prefix[2] == 0x66) {
1250           src_reg_file = dst_reg_file = SSE;
1251           prefix[2] = 0;  // clear prefix now it's served its purpose as part of the opcode
1252         } else {
1253           src_reg_file = dst_reg_file = MMX;
1254         }
1255         switch (*instr) {
1256           case 0xF4: opcode1 = "pmuludq"; break;
1257           case 0xF6: opcode1 = "psadbw"; break;
1258           case 0xF8: opcode1 = "psubb"; break;
1259           case 0xF9: opcode1 = "psubw"; break;
1260           case 0xFA: opcode1 = "psubd"; break;
1261           case 0xFB: opcode1 = "psubq"; break;
1262           case 0xFC: opcode1 = "paddb"; break;
1263           case 0xFD: opcode1 = "paddw"; break;
1264           case 0xFE: opcode1 = "paddd"; break;
1265         }
1266         prefix[2] = 0;
1267         has_modrm = true;
1268         load = true;
1269         break;
1270       default:
1271         opcode_tmp = StringPrintf("unknown opcode '0F %02X'", *instr);
1272         opcode1 = opcode_tmp.c_str();
1273         break;
1274     }
1275     break;
1276   case 0x80: case 0x81: case 0x82: case 0x83:
1277     static const char* x80_opcodes[] = {"add", "or", "adc", "sbb", "and", "sub", "xor", "cmp"};
1278     modrm_opcodes = x80_opcodes;
1279     has_modrm = true;
1280     reg_is_opcode = true;
1281     store = true;
1282     byte_operand = (*instr & 1) == 0;
1283     immediate_bytes = *instr == 0x81 ? 4 : 1;
1284     break;
1285   case 0x84: case 0x85:
1286     opcode1 = "test";
1287     has_modrm = true;
1288     load = true;
1289     byte_operand = (*instr & 1) == 0;
1290     break;
1291   case 0x8D:
1292     opcode1 = "lea";
1293     has_modrm = true;
1294     load = true;
1295     break;
1296   case 0x8F:
1297     opcode1 = "pop";
1298     has_modrm = true;
1299     reg_is_opcode = true;
1300     store = true;
1301     break;
1302   case 0x99:
1303     opcode1 = "cdq";
1304     break;
1305   case 0x9B:
1306     if (instr[1] == 0xDF && instr[2] == 0xE0) {
1307       opcode1 = "fstsw\tax";
1308       instr += 2;
1309     } else {
1310       opcode_tmp = StringPrintf("unknown opcode '%02X'", *instr);
1311       opcode1 = opcode_tmp.c_str();
1312     }
1313     break;
1314   case 0xA5:
1315     opcode1 = (prefix[2] == 0x66 ? "movsw" : "movsl");
1316     break;
1317   case 0xA7:
1318     opcode1 = (prefix[2] == 0x66 ? "cmpsw" : "cmpsl");
1319     break;
1320   case 0xAF:
1321     opcode1 = (prefix[2] == 0x66 ? "scasw" : "scasl");
1322     break;
1323   case 0xB0: case 0xB1: case 0xB2: case 0xB3: case 0xB4: case 0xB5: case 0xB6: case 0xB7:
1324     opcode1 = "mov";
1325     immediate_bytes = 1;
1326     byte_operand = true;
1327     reg_in_opcode = true;
1328     byte_operand = true;
1329     break;
1330   case 0xB8: case 0xB9: case 0xBA: case 0xBB: case 0xBC: case 0xBD: case 0xBE: case 0xBF:
1331     if ((rex & REX_W) != 0) {
1332       opcode1 = "movabsq";
1333       immediate_bytes = 8;
1334       reg_in_opcode = true;
1335       break;
1336     }
1337     opcode1 = "mov";
1338     immediate_bytes = 4;
1339     reg_in_opcode = true;
1340     break;
1341   case 0xC0: case 0xC1:
1342   case 0xD0: case 0xD1: case 0xD2: case 0xD3:
1343     static const char* shift_opcodes[] =
1344         {"rol", "ror", "rcl", "rcr", "shl", "shr", "unknown-shift", "sar"};
1345     modrm_opcodes = shift_opcodes;
1346     has_modrm = true;
1347     reg_is_opcode = true;
1348     store = true;
1349     immediate_bytes = ((*instr & 0xf0) == 0xc0) ? 1 : 0;
1350     cx = (*instr == 0xD2) || (*instr == 0xD3);
1351     byte_operand = (*instr == 0xC0);
1352     break;
1353   case 0xC3: opcode1 = "ret"; break;
1354   case 0xC6:
1355     static const char* c6_opcodes[] = {"mov",        "unknown-c6", "unknown-c6",
1356                                        "unknown-c6", "unknown-c6", "unknown-c6",
1357                                        "unknown-c6", "unknown-c6"};
1358     modrm_opcodes = c6_opcodes;
1359     store = true;
1360     immediate_bytes = 1;
1361     has_modrm = true;
1362     reg_is_opcode = true;
1363     byte_operand = true;
1364     break;
1365   case 0xC7:
1366     static const char* c7_opcodes[] = {"mov",        "unknown-c7", "unknown-c7",
1367                                        "unknown-c7", "unknown-c7", "unknown-c7",
1368                                        "unknown-c7", "unknown-c7"};
1369     modrm_opcodes = c7_opcodes;
1370     store = true;
1371     immediate_bytes = 4;
1372     has_modrm = true;
1373     reg_is_opcode = true;
1374     break;
1375   case 0xCC: opcode1 = "int 3"; break;
1376   case 0xD9:
1377     if (instr[1] == 0xF8) {
1378       opcode1 = "fprem";
1379       instr++;
1380     } else {
1381       static const char* d9_opcodes[] = {"flds", "unknown-d9", "fsts", "fstps", "fldenv", "fldcw",
1382                                          "fnstenv", "fnstcw"};
1383       modrm_opcodes = d9_opcodes;
1384       store = true;
1385       has_modrm = true;
1386       reg_is_opcode = true;
1387     }
1388     break;
1389   case 0xDA:
1390     if (instr[1] == 0xE9) {
1391       opcode1 = "fucompp";
1392       instr++;
1393     } else {
1394       opcode_tmp = StringPrintf("unknown opcode '%02X'", *instr);
1395       opcode1 = opcode_tmp.c_str();
1396     }
1397     break;
1398   case 0xDB:
1399     static const char* db_opcodes[] = {"fildl",      "unknown-db", "unknown-db",
1400                                        "unknown-db", "unknown-db", "unknown-db",
1401                                        "unknown-db", "unknown-db"};
1402     modrm_opcodes = db_opcodes;
1403     load = true;
1404     has_modrm = true;
1405     reg_is_opcode = true;
1406     break;
1407   case 0xDD:
1408     static const char* dd_opcodes[] = {"fldl",   "fisttp", "fstl",
1409                                        "fstpl",  "frstor", "unknown-dd",
1410                                        "fnsave", "fnstsw"};
1411     modrm_opcodes = dd_opcodes;
1412     store = true;
1413     has_modrm = true;
1414     reg_is_opcode = true;
1415     break;
1416   case 0xDF:
1417     static const char* df_opcodes[] = {"fild",       "unknown-df", "unknown-df",
1418                                        "unknown-df", "unknown-df", "fildll",
1419                                        "unknown-df", "unknown-df"};
1420     modrm_opcodes = df_opcodes;
1421     load = true;
1422     has_modrm = true;
1423     reg_is_opcode = true;
1424     break;
1425   case 0xE3: opcode1 = "jecxz"; branch_bytes = 1; break;
1426   case 0xE8: opcode1 = "call"; branch_bytes = 4; break;
1427   case 0xE9: opcode1 = "jmp"; branch_bytes = 4; break;
1428   case 0xEB: opcode1 = "jmp"; branch_bytes = 1; break;
1429   case 0xF5: opcode1 = "cmc"; break;
1430   case 0xF6: case 0xF7:
1431     static const char* f7_opcodes[] = {
1432         "test", "unknown-f7", "not", "neg", "mul edx:eax, eax *",
1433         "imul edx:eax, eax *", "div edx:eax, edx:eax /",
1434         "idiv edx:eax, edx:eax /"};
1435     modrm_opcodes = f7_opcodes;
1436     has_modrm = true;
1437     reg_is_opcode = true;
1438     store = true;
1439     immediate_bytes = ((instr[1] & 0x38) == 0) ? (instr[0] == 0xF7 ? 4 : 1) : 0;
1440     break;
1441   case 0xFF:
1442     {
1443       static const char* ff_opcodes[] = {
1444           "inc", "dec", "call", "call",
1445           "jmp", "jmp", "push", "unknown-ff"};
1446       modrm_opcodes = ff_opcodes;
1447       has_modrm = true;
1448       reg_is_opcode = true;
1449       load = true;
1450       const uint8_t opcode_digit = (instr[1] >> 3) & 7;
1451       // 'call', 'jmp' and 'push' are target specific instructions
1452       if (opcode_digit == 2 || opcode_digit == 4 || opcode_digit == 6) {
1453         target_specific = true;
1454       }
1455     }
1456     break;
1457   default:
1458     opcode_tmp = StringPrintf("unknown opcode '%02X'", *instr);
1459     opcode1 = opcode_tmp.c_str();
1460     break;
1461   }
1462   std::ostringstream args;
1463   // We force the REX prefix to be available for 64-bit target
1464   // in order to dump addr (base/index) registers correctly.
1465   uint8_t rex64 = supports_rex_ ? (rex | 0x40) : rex;
1466   // REX.W should be forced for 64-target and target-specific instructions (i.e., push or pop).
1467   uint8_t rex_w = (supports_rex_ && target_specific) ? (rex | 0x48) : rex;
1468   if (reg_in_opcode) {
1469     DCHECK(!has_modrm);
1470     DumpOpcodeReg(args, rex_w, *instr & 0x7, byte_operand, prefix[2]);
1471   }
1472   instr++;
1473   uint32_t address_bits = 0;
1474   if (has_modrm) {
1475     uint8_t modrm = *instr;
1476     instr++;
1477     uint8_t mod = modrm >> 6;
1478     uint8_t reg_or_opcode = (modrm >> 3) & 7;
1479     uint8_t rm = modrm & 7;
1480     std::string address = DumpAddress(mod, rm, rex64, rex_w, no_ops, byte_operand,
1481                                       byte_second_operand, prefix, load, src_reg_file, dst_reg_file,
1482                                       &instr, &address_bits);
1483 
1484     if (reg_is_opcode && modrm_opcodes != nullptr) {
1485       opcode3 = modrm_opcodes[reg_or_opcode];
1486     }
1487 
1488     // Add opcode suffixes to indicate size.
1489     if (byte_operand) {
1490       opcode4 = "b";
1491     } else if ((rex & REX_W) != 0) {
1492       opcode4 = "q";
1493     } else if (prefix[2] == 0x66) {
1494       opcode4 = "w";
1495     }
1496 
1497     if (load) {
1498       if (!reg_is_opcode) {
1499         DumpReg(args, rex, reg_or_opcode, byte_operand, prefix[2], dst_reg_file);
1500         args << ", ";
1501       }
1502       DumpSegmentOverride(args, prefix[1]);
1503       args << address;
1504     } else {
1505       DCHECK(store);
1506       DumpSegmentOverride(args, prefix[1]);
1507       args << address;
1508       if (!reg_is_opcode) {
1509         args << ", ";
1510         DumpReg(args, rex, reg_or_opcode, byte_operand, prefix[2], src_reg_file);
1511       }
1512     }
1513   }
1514   if (ax) {
1515     // If this opcode implicitly uses ax, ax is always the first arg.
1516     DumpReg(args, rex, 0 /* EAX */, byte_operand, prefix[2], GPR);
1517   }
1518   if (cx) {
1519     args << ", ";
1520     DumpReg(args, rex, 1 /* ECX */, true, prefix[2], GPR);
1521   }
1522   if (immediate_bytes > 0) {
1523     if (has_modrm || reg_in_opcode || ax || cx) {
1524       args << ", ";
1525     }
1526     if (immediate_bytes == 1) {
1527       args << StringPrintf("%d", *reinterpret_cast<const int8_t*>(instr));
1528       instr++;
1529     } else if (immediate_bytes == 4) {
1530       if (prefix[2] == 0x66) {  // Operand size override from 32-bit to 16-bit.
1531         args << StringPrintf("%d", *reinterpret_cast<const int16_t*>(instr));
1532         instr += 2;
1533       } else {
1534         args << StringPrintf("%d", *reinterpret_cast<const int32_t*>(instr));
1535         instr += 4;
1536       }
1537     } else {
1538       CHECK_EQ(immediate_bytes, 8u);
1539       args << StringPrintf("%" PRId64, *reinterpret_cast<const int64_t*>(instr));
1540       instr += 8;
1541     }
1542   } else if (branch_bytes > 0) {
1543     DCHECK(!has_modrm);
1544     int32_t displacement;
1545     if (branch_bytes == 1) {
1546       displacement = *reinterpret_cast<const int8_t*>(instr);
1547       instr++;
1548     } else {
1549       CHECK_EQ(branch_bytes, 4u);
1550       displacement = *reinterpret_cast<const int32_t*>(instr);
1551       instr += 4;
1552     }
1553     args << StringPrintf("%+d (", displacement)
1554          << FormatInstructionPointer(instr + displacement)
1555          << ")";
1556   }
1557   if (prefix[1] == kFs && !supports_rex_) {
1558     args << "  ; ";
1559     GetDisassemblerOptions()->thread_offset_name_function_(args, address_bits);
1560   }
1561   if (prefix[1] == kGs && supports_rex_) {
1562     args << "  ; ";
1563     GetDisassemblerOptions()->thread_offset_name_function_(args, address_bits);
1564   }
1565   const char* prefix_str;
1566   switch (prefix[0]) {
1567     case 0xF0: prefix_str = "lock "; break;
1568     case 0xF2: prefix_str = "repne "; break;
1569     case 0xF3: prefix_str = "repe "; break;
1570     case 0: prefix_str = ""; break;
1571     default: LOG(FATAL) << "Unreachable"; UNREACHABLE();
1572   }
1573   os << FormatInstructionPointer(begin_instr)
1574      << StringPrintf(": %22s    \t%-7s%s%s%s%s%s ", DumpCodeHex(begin_instr, instr).c_str(),
1575                      prefix_str, opcode0, opcode1, opcode2, opcode3, opcode4)
1576      << args.str() << '\n';
1577   return instr - begin_instr;
1578 }  // NOLINT(readability/fn_size)
1579 
1580 }  // namespace x86
1581 }  // namespace art
1582