1 // Copyright 2007-2008 the V8 project authors. All rights reserved. 2 // Redistribution and use in source and binary forms, with or without 3 // modification, are permitted provided that the following conditions are 4 // met: 5 // 6 // * Redistributions of source code must retain the above copyright 7 // notice, this list of conditions and the following disclaimer. 8 // * Redistributions in binary form must reproduce the above 9 // copyright notice, this list of conditions and the following 10 // disclaimer in the documentation and/or other materials provided 11 // with the distribution. 12 // * Neither the name of Google Inc. nor the names of its 13 // contributors may be used to endorse or promote products derived 14 // from this software without specific prior written permission. 15 // 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28 #include <assert.h> 29 #include <stdio.h> 30 #include <stdarg.h> 31 32 #include "v8.h" 33 #include "disasm.h" 34 35 namespace disasm { 36 37 enum OperandOrder { 38 UNSET_OP_ORDER = 0, 39 REG_OPER_OP_ORDER, 40 OPER_REG_OP_ORDER 41 }; 42 43 44 //------------------------------------------------------------------ 45 // Tables 46 //------------------------------------------------------------------ 47 struct ByteMnemonic { 48 int b; // -1 terminates, otherwise must be in range (0..255) 49 const char* mnem; 50 OperandOrder op_order_; 51 }; 52 53 54 static ByteMnemonic two_operands_instr[] = { 55 {0x03, "add", REG_OPER_OP_ORDER}, 56 {0x09, "or", OPER_REG_OP_ORDER}, 57 {0x0B, "or", REG_OPER_OP_ORDER}, 58 {0x1B, "sbb", REG_OPER_OP_ORDER}, 59 {0x21, "and", OPER_REG_OP_ORDER}, 60 {0x23, "and", REG_OPER_OP_ORDER}, 61 {0x29, "sub", OPER_REG_OP_ORDER}, 62 {0x2A, "subb", REG_OPER_OP_ORDER}, 63 {0x2B, "sub", REG_OPER_OP_ORDER}, 64 {0x31, "xor", OPER_REG_OP_ORDER}, 65 {0x33, "xor", REG_OPER_OP_ORDER}, 66 {0x38, "cmpb", OPER_REG_OP_ORDER}, 67 {0x3A, "cmpb", REG_OPER_OP_ORDER}, 68 {0x3B, "cmp", REG_OPER_OP_ORDER}, 69 {0x84, "test_b", REG_OPER_OP_ORDER}, 70 {0x85, "test", REG_OPER_OP_ORDER}, 71 {0x87, "xchg", REG_OPER_OP_ORDER}, 72 {0x8A, "mov_b", REG_OPER_OP_ORDER}, 73 {0x8B, "mov", REG_OPER_OP_ORDER}, 74 {0x8D, "lea", REG_OPER_OP_ORDER}, 75 {-1, "", UNSET_OP_ORDER} 76 }; 77 78 79 static ByteMnemonic zero_operands_instr[] = { 80 {0xC3, "ret", UNSET_OP_ORDER}, 81 {0xC9, "leave", UNSET_OP_ORDER}, 82 {0x90, "nop", UNSET_OP_ORDER}, 83 {0xF4, "hlt", UNSET_OP_ORDER}, 84 {0xCC, "int3", UNSET_OP_ORDER}, 85 {0x60, "pushad", UNSET_OP_ORDER}, 86 {0x61, "popad", UNSET_OP_ORDER}, 87 {0x9C, "pushfd", UNSET_OP_ORDER}, 88 {0x9D, "popfd", UNSET_OP_ORDER}, 89 {0x9E, "sahf", UNSET_OP_ORDER}, 90 {0x99, "cdq", UNSET_OP_ORDER}, 91 {0x9B, "fwait", UNSET_OP_ORDER}, 92 {-1, "", UNSET_OP_ORDER} 93 }; 94 95 96 static ByteMnemonic call_jump_instr[] = { 97 {0xE8, "call", UNSET_OP_ORDER}, 98 {0xE9, "jmp", UNSET_OP_ORDER}, 99 {-1, "", UNSET_OP_ORDER} 100 }; 101 102 103 static ByteMnemonic short_immediate_instr[] = { 104 {0x05, "add", UNSET_OP_ORDER}, 105 {0x0D, "or", UNSET_OP_ORDER}, 106 {0x15, "adc", UNSET_OP_ORDER}, 107 {0x25, "and", UNSET_OP_ORDER}, 108 {0x2D, "sub", UNSET_OP_ORDER}, 109 {0x35, "xor", UNSET_OP_ORDER}, 110 {0x3D, "cmp", UNSET_OP_ORDER}, 111 {-1, "", UNSET_OP_ORDER} 112 }; 113 114 115 static const char* jump_conditional_mnem[] = { 116 /*0*/ "jo", "jno", "jc", "jnc", 117 /*4*/ "jz", "jnz", "jna", "ja", 118 /*8*/ "js", "jns", "jpe", "jpo", 119 /*12*/ "jl", "jnl", "jng", "jg" 120 }; 121 122 123 static const char* set_conditional_mnem[] = { 124 /*0*/ "seto", "setno", "setc", "setnc", 125 /*4*/ "setz", "setnz", "setna", "seta", 126 /*8*/ "sets", "setns", "setpe", "setpo", 127 /*12*/ "setl", "setnl", "setng", "setg" 128 }; 129 130 131 static const char* conditional_move_mnem[] = { 132 /*0*/ "cmovo", "cmovno", "cmovc", "cmovnc", 133 /*4*/ "cmovz", "cmovnz", "cmovna", "cmova", 134 /*8*/ "cmovs", "cmovns", "cmovpe", "cmovpo", 135 /*12*/ "cmovl", "cmovnl", "cmovng", "cmovg" 136 }; 137 138 139 enum InstructionType { 140 NO_INSTR, 141 ZERO_OPERANDS_INSTR, 142 TWO_OPERANDS_INSTR, 143 JUMP_CONDITIONAL_SHORT_INSTR, 144 REGISTER_INSTR, 145 MOVE_REG_INSTR, 146 CALL_JUMP_INSTR, 147 SHORT_IMMEDIATE_INSTR 148 }; 149 150 151 struct InstructionDesc { 152 const char* mnem; 153 InstructionType type; 154 OperandOrder op_order_; 155 }; 156 157 158 class InstructionTable { 159 public: 160 InstructionTable(); 161 const InstructionDesc& Get(byte x) const { return instructions_[x]; } 162 163 private: 164 InstructionDesc instructions_[256]; 165 void Clear(); 166 void Init(); 167 void CopyTable(ByteMnemonic bm[], InstructionType type); 168 void SetTableRange(InstructionType type, 169 byte start, 170 byte end, 171 const char* mnem); 172 void AddJumpConditionalShort(); 173 }; 174 175 176 InstructionTable::InstructionTable() { 177 Clear(); 178 Init(); 179 } 180 181 182 void InstructionTable::Clear() { 183 for (int i = 0; i < 256; i++) { 184 instructions_[i].mnem = ""; 185 instructions_[i].type = NO_INSTR; 186 instructions_[i].op_order_ = UNSET_OP_ORDER; 187 } 188 } 189 190 191 void InstructionTable::Init() { 192 CopyTable(two_operands_instr, TWO_OPERANDS_INSTR); 193 CopyTable(zero_operands_instr, ZERO_OPERANDS_INSTR); 194 CopyTable(call_jump_instr, CALL_JUMP_INSTR); 195 CopyTable(short_immediate_instr, SHORT_IMMEDIATE_INSTR); 196 AddJumpConditionalShort(); 197 SetTableRange(REGISTER_INSTR, 0x40, 0x47, "inc"); 198 SetTableRange(REGISTER_INSTR, 0x48, 0x4F, "dec"); 199 SetTableRange(REGISTER_INSTR, 0x50, 0x57, "push"); 200 SetTableRange(REGISTER_INSTR, 0x58, 0x5F, "pop"); 201 SetTableRange(REGISTER_INSTR, 0x91, 0x97, "xchg eax,"); // 0x90 is nop. 202 SetTableRange(MOVE_REG_INSTR, 0xB8, 0xBF, "mov"); 203 } 204 205 206 void InstructionTable::CopyTable(ByteMnemonic bm[], InstructionType type) { 207 for (int i = 0; bm[i].b >= 0; i++) { 208 InstructionDesc* id = &instructions_[bm[i].b]; 209 id->mnem = bm[i].mnem; 210 id->op_order_ = bm[i].op_order_; 211 ASSERT_EQ(NO_INSTR, id->type); // Information not already entered. 212 id->type = type; 213 } 214 } 215 216 217 void InstructionTable::SetTableRange(InstructionType type, 218 byte start, 219 byte end, 220 const char* mnem) { 221 for (byte b = start; b <= end; b++) { 222 InstructionDesc* id = &instructions_[b]; 223 ASSERT_EQ(NO_INSTR, id->type); // Information not already entered. 224 id->mnem = mnem; 225 id->type = type; 226 } 227 } 228 229 230 void InstructionTable::AddJumpConditionalShort() { 231 for (byte b = 0x70; b <= 0x7F; b++) { 232 InstructionDesc* id = &instructions_[b]; 233 ASSERT_EQ(NO_INSTR, id->type); // Information not already entered. 234 id->mnem = jump_conditional_mnem[b & 0x0F]; 235 id->type = JUMP_CONDITIONAL_SHORT_INSTR; 236 } 237 } 238 239 240 static InstructionTable instruction_table; 241 242 243 // The IA32 disassembler implementation. 244 class DisassemblerIA32 { 245 public: 246 DisassemblerIA32(const NameConverter& converter, 247 bool abort_on_unimplemented = true) 248 : converter_(converter), 249 tmp_buffer_pos_(0), 250 abort_on_unimplemented_(abort_on_unimplemented) { 251 tmp_buffer_[0] = '\0'; 252 } 253 254 virtual ~DisassemblerIA32() {} 255 256 // Writes one disassembled instruction into 'buffer' (0-terminated). 257 // Returns the length of the disassembled machine instruction in bytes. 258 int InstructionDecode(v8::internal::Vector<char> buffer, byte* instruction); 259 260 private: 261 const NameConverter& converter_; 262 v8::internal::EmbeddedVector<char, 128> tmp_buffer_; 263 unsigned int tmp_buffer_pos_; 264 bool abort_on_unimplemented_; 265 266 267 enum { 268 eax = 0, 269 ecx = 1, 270 edx = 2, 271 ebx = 3, 272 esp = 4, 273 ebp = 5, 274 esi = 6, 275 edi = 7 276 }; 277 278 279 enum ShiftOpcodeExtension { 280 kROL = 0, 281 kROR = 1, 282 kRCL = 2, 283 kRCR = 3, 284 kSHL = 4, 285 KSHR = 5, 286 kSAR = 7 287 }; 288 289 290 const char* NameOfCPURegister(int reg) const { 291 return converter_.NameOfCPURegister(reg); 292 } 293 294 295 const char* NameOfByteCPURegister(int reg) const { 296 return converter_.NameOfByteCPURegister(reg); 297 } 298 299 300 const char* NameOfXMMRegister(int reg) const { 301 return converter_.NameOfXMMRegister(reg); 302 } 303 304 305 const char* NameOfAddress(byte* addr) const { 306 return converter_.NameOfAddress(addr); 307 } 308 309 310 // Disassembler helper functions. 311 static void get_modrm(byte data, int* mod, int* regop, int* rm) { 312 *mod = (data >> 6) & 3; 313 *regop = (data & 0x38) >> 3; 314 *rm = data & 7; 315 } 316 317 318 static void get_sib(byte data, int* scale, int* index, int* base) { 319 *scale = (data >> 6) & 3; 320 *index = (data >> 3) & 7; 321 *base = data & 7; 322 } 323 324 typedef const char* (DisassemblerIA32::*RegisterNameMapping)(int reg) const; 325 326 int PrintRightOperandHelper(byte* modrmp, RegisterNameMapping register_name); 327 int PrintRightOperand(byte* modrmp); 328 int PrintRightByteOperand(byte* modrmp); 329 int PrintOperands(const char* mnem, OperandOrder op_order, byte* data); 330 int PrintImmediateOp(byte* data); 331 int F7Instruction(byte* data); 332 int D1D3C1Instruction(byte* data); 333 int JumpShort(byte* data); 334 int JumpConditional(byte* data, const char* comment); 335 int JumpConditionalShort(byte* data, const char* comment); 336 int SetCC(byte* data); 337 int CMov(byte* data); 338 int FPUInstruction(byte* data); 339 int MemoryFPUInstruction(int escape_opcode, int regop, byte* modrm_start); 340 int RegisterFPUInstruction(int escape_opcode, byte modrm_byte); 341 void AppendToBuffer(const char* format, ...); 342 343 344 void UnimplementedInstruction() { 345 if (abort_on_unimplemented_) { 346 UNIMPLEMENTED(); 347 } else { 348 AppendToBuffer("'Unimplemented Instruction'"); 349 } 350 } 351 }; 352 353 354 void DisassemblerIA32::AppendToBuffer(const char* format, ...) { 355 v8::internal::Vector<char> buf = tmp_buffer_ + tmp_buffer_pos_; 356 va_list args; 357 va_start(args, format); 358 int result = v8::internal::OS::VSNPrintF(buf, format, args); 359 va_end(args); 360 tmp_buffer_pos_ += result; 361 } 362 363 int DisassemblerIA32::PrintRightOperandHelper( 364 byte* modrmp, 365 RegisterNameMapping register_name) { 366 int mod, regop, rm; 367 get_modrm(*modrmp, &mod, ®op, &rm); 368 switch (mod) { 369 case 0: 370 if (rm == ebp) { 371 int32_t disp = *reinterpret_cast<int32_t*>(modrmp+1); 372 AppendToBuffer("[0x%x]", disp); 373 return 5; 374 } else if (rm == esp) { 375 byte sib = *(modrmp + 1); 376 int scale, index, base; 377 get_sib(sib, &scale, &index, &base); 378 if (index == esp && base == esp && scale == 0 /*times_1*/) { 379 AppendToBuffer("[%s]", (this->*register_name)(rm)); 380 return 2; 381 } else if (base == ebp) { 382 int32_t disp = *reinterpret_cast<int32_t*>(modrmp + 2); 383 AppendToBuffer("[%s*%d+0x%x]", 384 (this->*register_name)(index), 385 1 << scale, 386 disp); 387 return 6; 388 } else if (index != esp && base != ebp) { 389 // [base+index*scale] 390 AppendToBuffer("[%s+%s*%d]", 391 (this->*register_name)(base), 392 (this->*register_name)(index), 393 1 << scale); 394 return 2; 395 } else { 396 UnimplementedInstruction(); 397 return 1; 398 } 399 } else { 400 AppendToBuffer("[%s]", (this->*register_name)(rm)); 401 return 1; 402 } 403 break; 404 case 1: // fall through 405 case 2: 406 if (rm == esp) { 407 byte sib = *(modrmp + 1); 408 int scale, index, base; 409 get_sib(sib, &scale, &index, &base); 410 int disp = 411 mod == 2 ? *reinterpret_cast<int32_t*>(modrmp + 2) : *(modrmp + 2); 412 if (index == base && index == rm /*esp*/ && scale == 0 /*times_1*/) { 413 AppendToBuffer("[%s+0x%x]", (this->*register_name)(rm), disp); 414 } else { 415 AppendToBuffer("[%s+%s*%d+0x%x]", 416 (this->*register_name)(base), 417 (this->*register_name)(index), 418 1 << scale, 419 disp); 420 } 421 return mod == 2 ? 6 : 3; 422 } else { 423 // No sib. 424 int disp = 425 mod == 2 ? *reinterpret_cast<int32_t*>(modrmp + 1) : *(modrmp + 1); 426 AppendToBuffer("[%s+0x%x]", (this->*register_name)(rm), disp); 427 return mod == 2 ? 5 : 2; 428 } 429 break; 430 case 3: 431 AppendToBuffer("%s", (this->*register_name)(rm)); 432 return 1; 433 default: 434 UnimplementedInstruction(); 435 return 1; 436 } 437 UNREACHABLE(); 438 } 439 440 441 int DisassemblerIA32::PrintRightOperand(byte* modrmp) { 442 return PrintRightOperandHelper(modrmp, &DisassemblerIA32::NameOfCPURegister); 443 } 444 445 446 int DisassemblerIA32::PrintRightByteOperand(byte* modrmp) { 447 return PrintRightOperandHelper(modrmp, 448 &DisassemblerIA32::NameOfByteCPURegister); 449 } 450 451 452 // Returns number of bytes used including the current *data. 453 // Writes instruction's mnemonic, left and right operands to 'tmp_buffer_'. 454 int DisassemblerIA32::PrintOperands(const char* mnem, 455 OperandOrder op_order, 456 byte* data) { 457 byte modrm = *data; 458 int mod, regop, rm; 459 get_modrm(modrm, &mod, ®op, &rm); 460 int advance = 0; 461 switch (op_order) { 462 case REG_OPER_OP_ORDER: { 463 AppendToBuffer("%s %s,", mnem, NameOfCPURegister(regop)); 464 advance = PrintRightOperand(data); 465 break; 466 } 467 case OPER_REG_OP_ORDER: { 468 AppendToBuffer("%s ", mnem); 469 advance = PrintRightOperand(data); 470 AppendToBuffer(",%s", NameOfCPURegister(regop)); 471 break; 472 } 473 default: 474 UNREACHABLE(); 475 break; 476 } 477 return advance; 478 } 479 480 481 // Returns number of bytes used by machine instruction, including *data byte. 482 // Writes immediate instructions to 'tmp_buffer_'. 483 int DisassemblerIA32::PrintImmediateOp(byte* data) { 484 bool sign_extension_bit = (*data & 0x02) != 0; 485 byte modrm = *(data+1); 486 int mod, regop, rm; 487 get_modrm(modrm, &mod, ®op, &rm); 488 const char* mnem = "Imm???"; 489 switch (regop) { 490 case 0: mnem = "add"; break; 491 case 1: mnem = "or"; break; 492 case 2: mnem = "adc"; break; 493 case 4: mnem = "and"; break; 494 case 5: mnem = "sub"; break; 495 case 6: mnem = "xor"; break; 496 case 7: mnem = "cmp"; break; 497 default: UnimplementedInstruction(); 498 } 499 AppendToBuffer("%s ", mnem); 500 int count = PrintRightOperand(data+1); 501 if (sign_extension_bit) { 502 AppendToBuffer(",0x%x", *(data + 1 + count)); 503 return 1 + count + 1 /*int8*/; 504 } else { 505 AppendToBuffer(",0x%x", *reinterpret_cast<int32_t*>(data + 1 + count)); 506 return 1 + count + 4 /*int32_t*/; 507 } 508 } 509 510 511 // Returns number of bytes used, including *data. 512 int DisassemblerIA32::F7Instruction(byte* data) { 513 ASSERT_EQ(0xF7, *data); 514 byte modrm = *(data+1); 515 int mod, regop, rm; 516 get_modrm(modrm, &mod, ®op, &rm); 517 if (mod == 3 && regop != 0) { 518 const char* mnem = NULL; 519 switch (regop) { 520 case 2: mnem = "not"; break; 521 case 3: mnem = "neg"; break; 522 case 4: mnem = "mul"; break; 523 case 7: mnem = "idiv"; break; 524 default: UnimplementedInstruction(); 525 } 526 AppendToBuffer("%s %s", mnem, NameOfCPURegister(rm)); 527 return 2; 528 } else if (mod == 3 && regop == eax) { 529 int32_t imm = *reinterpret_cast<int32_t*>(data+2); 530 AppendToBuffer("test %s,0x%x", NameOfCPURegister(rm), imm); 531 return 6; 532 } else if (regop == eax) { 533 AppendToBuffer("test "); 534 int count = PrintRightOperand(data+1); 535 int32_t imm = *reinterpret_cast<int32_t*>(data+1+count); 536 AppendToBuffer(",0x%x", imm); 537 return 1+count+4 /*int32_t*/; 538 } else { 539 UnimplementedInstruction(); 540 return 2; 541 } 542 } 543 544 int DisassemblerIA32::D1D3C1Instruction(byte* data) { 545 byte op = *data; 546 ASSERT(op == 0xD1 || op == 0xD3 || op == 0xC1); 547 byte modrm = *(data+1); 548 int mod, regop, rm; 549 get_modrm(modrm, &mod, ®op, &rm); 550 int imm8 = -1; 551 int num_bytes = 2; 552 if (mod == 3) { 553 const char* mnem = NULL; 554 switch (regop) { 555 case kROL: mnem = "rol"; break; 556 case kROR: mnem = "ror"; break; 557 case kRCL: mnem = "rcl"; break; 558 case kSHL: mnem = "shl"; break; 559 case KSHR: mnem = "shr"; break; 560 case kSAR: mnem = "sar"; break; 561 default: UnimplementedInstruction(); 562 } 563 if (op == 0xD1) { 564 imm8 = 1; 565 } else if (op == 0xC1) { 566 imm8 = *(data+2); 567 num_bytes = 3; 568 } else if (op == 0xD3) { 569 // Shift/rotate by cl. 570 } 571 ASSERT_NE(NULL, mnem); 572 AppendToBuffer("%s %s,", mnem, NameOfCPURegister(rm)); 573 if (imm8 > 0) { 574 AppendToBuffer("%d", imm8); 575 } else { 576 AppendToBuffer("cl"); 577 } 578 } else { 579 UnimplementedInstruction(); 580 } 581 return num_bytes; 582 } 583 584 585 // Returns number of bytes used, including *data. 586 int DisassemblerIA32::JumpShort(byte* data) { 587 ASSERT_EQ(0xEB, *data); 588 byte b = *(data+1); 589 byte* dest = data + static_cast<int8_t>(b) + 2; 590 AppendToBuffer("jmp %s", NameOfAddress(dest)); 591 return 2; 592 } 593 594 595 // Returns number of bytes used, including *data. 596 int DisassemblerIA32::JumpConditional(byte* data, const char* comment) { 597 ASSERT_EQ(0x0F, *data); 598 byte cond = *(data+1) & 0x0F; 599 byte* dest = data + *reinterpret_cast<int32_t*>(data+2) + 6; 600 const char* mnem = jump_conditional_mnem[cond]; 601 AppendToBuffer("%s %s", mnem, NameOfAddress(dest)); 602 if (comment != NULL) { 603 AppendToBuffer(", %s", comment); 604 } 605 return 6; // includes 0x0F 606 } 607 608 609 // Returns number of bytes used, including *data. 610 int DisassemblerIA32::JumpConditionalShort(byte* data, const char* comment) { 611 byte cond = *data & 0x0F; 612 byte b = *(data+1); 613 byte* dest = data + static_cast<int8_t>(b) + 2; 614 const char* mnem = jump_conditional_mnem[cond]; 615 AppendToBuffer("%s %s", mnem, NameOfAddress(dest)); 616 if (comment != NULL) { 617 AppendToBuffer(", %s", comment); 618 } 619 return 2; 620 } 621 622 623 // Returns number of bytes used, including *data. 624 int DisassemblerIA32::SetCC(byte* data) { 625 ASSERT_EQ(0x0F, *data); 626 byte cond = *(data+1) & 0x0F; 627 const char* mnem = set_conditional_mnem[cond]; 628 AppendToBuffer("%s ", mnem); 629 PrintRightByteOperand(data+2); 630 return 3; // Includes 0x0F. 631 } 632 633 634 // Returns number of bytes used, including *data. 635 int DisassemblerIA32::CMov(byte* data) { 636 ASSERT_EQ(0x0F, *data); 637 byte cond = *(data + 1) & 0x0F; 638 const char* mnem = conditional_move_mnem[cond]; 639 int op_size = PrintOperands(mnem, REG_OPER_OP_ORDER, data + 2); 640 return 2 + op_size; // includes 0x0F 641 } 642 643 644 // Returns number of bytes used, including *data. 645 int DisassemblerIA32::FPUInstruction(byte* data) { 646 byte escape_opcode = *data; 647 ASSERT_EQ(0xD8, escape_opcode & 0xF8); 648 byte modrm_byte = *(data+1); 649 650 if (modrm_byte >= 0xC0) { 651 return RegisterFPUInstruction(escape_opcode, modrm_byte); 652 } else { 653 return MemoryFPUInstruction(escape_opcode, modrm_byte, data+1); 654 } 655 } 656 657 int DisassemblerIA32::MemoryFPUInstruction(int escape_opcode, 658 int modrm_byte, 659 byte* modrm_start) { 660 const char* mnem = "?"; 661 int regop = (modrm_byte >> 3) & 0x7; // reg/op field of modrm byte. 662 switch (escape_opcode) { 663 case 0xD9: switch (regop) { 664 case 0: mnem = "fld_s"; break; 665 case 3: mnem = "fstp_s"; break; 666 case 7: mnem = "fstcw"; break; 667 default: UnimplementedInstruction(); 668 } 669 break; 670 671 case 0xDB: switch (regop) { 672 case 0: mnem = "fild_s"; break; 673 case 1: mnem = "fisttp_s"; break; 674 case 2: mnem = "fist_s"; break; 675 case 3: mnem = "fistp_s"; break; 676 default: UnimplementedInstruction(); 677 } 678 break; 679 680 case 0xDD: switch (regop) { 681 case 0: mnem = "fld_d"; break; 682 case 2: mnem = "fstp"; break; 683 case 3: mnem = "fstp_d"; break; 684 default: UnimplementedInstruction(); 685 } 686 break; 687 688 case 0xDF: switch (regop) { 689 case 5: mnem = "fild_d"; break; 690 case 7: mnem = "fistp_d"; break; 691 default: UnimplementedInstruction(); 692 } 693 break; 694 695 default: UnimplementedInstruction(); 696 } 697 AppendToBuffer("%s ", mnem); 698 int count = PrintRightOperand(modrm_start); 699 return count + 1; 700 } 701 702 int DisassemblerIA32::RegisterFPUInstruction(int escape_opcode, 703 byte modrm_byte) { 704 bool has_register = false; // Is the FPU register encoded in modrm_byte? 705 const char* mnem = "?"; 706 707 switch (escape_opcode) { 708 case 0xD8: 709 UnimplementedInstruction(); 710 break; 711 712 case 0xD9: 713 switch (modrm_byte & 0xF8) { 714 case 0xC8: 715 mnem = "fxch"; 716 has_register = true; 717 break; 718 default: 719 switch (modrm_byte) { 720 case 0xE0: mnem = "fchs"; break; 721 case 0xE1: mnem = "fabs"; break; 722 case 0xE4: mnem = "ftst"; break; 723 case 0xE8: mnem = "fld1"; break; 724 case 0xEB: mnem = "fldpi"; break; 725 case 0xEE: mnem = "fldz"; break; 726 case 0xF5: mnem = "fprem1"; break; 727 case 0xF7: mnem = "fincstp"; break; 728 case 0xF8: mnem = "fprem"; break; 729 case 0xFE: mnem = "fsin"; break; 730 case 0xFF: mnem = "fcos"; break; 731 default: UnimplementedInstruction(); 732 } 733 } 734 break; 735 736 case 0xDA: 737 if (modrm_byte == 0xE9) { 738 mnem = "fucompp"; 739 } else { 740 UnimplementedInstruction(); 741 } 742 break; 743 744 case 0xDB: 745 if ((modrm_byte & 0xF8) == 0xE8) { 746 mnem = "fucomi"; 747 has_register = true; 748 } else if (modrm_byte == 0xE2) { 749 mnem = "fclex"; 750 } else { 751 UnimplementedInstruction(); 752 } 753 break; 754 755 case 0xDC: 756 has_register = true; 757 switch (modrm_byte & 0xF8) { 758 case 0xC0: mnem = "fadd"; break; 759 case 0xE8: mnem = "fsub"; break; 760 case 0xC8: mnem = "fmul"; break; 761 case 0xF8: mnem = "fdiv"; break; 762 default: UnimplementedInstruction(); 763 } 764 break; 765 766 case 0xDD: 767 has_register = true; 768 switch (modrm_byte & 0xF8) { 769 case 0xC0: mnem = "ffree"; break; 770 case 0xD8: mnem = "fstp"; break; 771 default: UnimplementedInstruction(); 772 } 773 break; 774 775 case 0xDE: 776 if (modrm_byte == 0xD9) { 777 mnem = "fcompp"; 778 } else { 779 has_register = true; 780 switch (modrm_byte & 0xF8) { 781 case 0xC0: mnem = "faddp"; break; 782 case 0xE8: mnem = "fsubp"; break; 783 case 0xC8: mnem = "fmulp"; break; 784 case 0xF8: mnem = "fdivp"; break; 785 default: UnimplementedInstruction(); 786 } 787 } 788 break; 789 790 case 0xDF: 791 if (modrm_byte == 0xE0) { 792 mnem = "fnstsw_ax"; 793 } else if ((modrm_byte & 0xF8) == 0xE8) { 794 mnem = "fucomip"; 795 has_register = true; 796 } 797 break; 798 799 default: UnimplementedInstruction(); 800 } 801 802 if (has_register) { 803 AppendToBuffer("%s st%d", mnem, modrm_byte & 0x7); 804 } else { 805 AppendToBuffer("%s", mnem); 806 } 807 return 2; 808 } 809 810 811 // Mnemonics for instructions 0xF0 byte. 812 // Returns NULL if the instruction is not handled here. 813 static const char* F0Mnem(byte f0byte) { 814 switch (f0byte) { 815 case 0xA2: return "cpuid"; 816 case 0x31: return "rdtsc"; 817 case 0xBE: return "movsx_b"; 818 case 0xBF: return "movsx_w"; 819 case 0xB6: return "movzx_b"; 820 case 0xB7: return "movzx_w"; 821 case 0xAF: return "imul"; 822 case 0xA5: return "shld"; 823 case 0xAD: return "shrd"; 824 case 0xAB: return "bts"; 825 default: return NULL; 826 } 827 } 828 829 830 // Disassembled instruction '*instr' and writes it into 'out_buffer'. 831 int DisassemblerIA32::InstructionDecode(v8::internal::Vector<char> out_buffer, 832 byte* instr) { 833 tmp_buffer_pos_ = 0; // starting to write as position 0 834 byte* data = instr; 835 // Check for hints. 836 const char* branch_hint = NULL; 837 // We use these two prefixes only with branch prediction 838 if (*data == 0x3E /*ds*/) { 839 branch_hint = "predicted taken"; 840 data++; 841 } else if (*data == 0x2E /*cs*/) { 842 branch_hint = "predicted not taken"; 843 data++; 844 } 845 bool processed = true; // Will be set to false if the current instruction 846 // is not in 'instructions' table. 847 const InstructionDesc& idesc = instruction_table.Get(*data); 848 switch (idesc.type) { 849 case ZERO_OPERANDS_INSTR: 850 AppendToBuffer(idesc.mnem); 851 data++; 852 break; 853 854 case TWO_OPERANDS_INSTR: 855 data++; 856 data += PrintOperands(idesc.mnem, idesc.op_order_, data); 857 break; 858 859 case JUMP_CONDITIONAL_SHORT_INSTR: 860 data += JumpConditionalShort(data, branch_hint); 861 break; 862 863 case REGISTER_INSTR: 864 AppendToBuffer("%s %s", idesc.mnem, NameOfCPURegister(*data & 0x07)); 865 data++; 866 break; 867 868 case MOVE_REG_INSTR: { 869 byte* addr = reinterpret_cast<byte*>(*reinterpret_cast<int32_t*>(data+1)); 870 AppendToBuffer("mov %s,%s", 871 NameOfCPURegister(*data & 0x07), 872 NameOfAddress(addr)); 873 data += 5; 874 break; 875 } 876 877 case CALL_JUMP_INSTR: { 878 byte* addr = data + *reinterpret_cast<int32_t*>(data+1) + 5; 879 AppendToBuffer("%s %s", idesc.mnem, NameOfAddress(addr)); 880 data += 5; 881 break; 882 } 883 884 case SHORT_IMMEDIATE_INSTR: { 885 byte* addr = reinterpret_cast<byte*>(*reinterpret_cast<int32_t*>(data+1)); 886 AppendToBuffer("%s eax, %s", idesc.mnem, NameOfAddress(addr)); 887 data += 5; 888 break; 889 } 890 891 case NO_INSTR: 892 processed = false; 893 break; 894 895 default: 896 UNIMPLEMENTED(); // This type is not implemented. 897 } 898 //---------------------------- 899 if (!processed) { 900 switch (*data) { 901 case 0xC2: 902 AppendToBuffer("ret 0x%x", *reinterpret_cast<uint16_t*>(data+1)); 903 data += 3; 904 break; 905 906 case 0x69: // fall through 907 case 0x6B: 908 { int mod, regop, rm; 909 get_modrm(*(data+1), &mod, ®op, &rm); 910 int32_t imm = 911 *data == 0x6B ? *(data+2) : *reinterpret_cast<int32_t*>(data+2); 912 AppendToBuffer("imul %s,%s,0x%x", 913 NameOfCPURegister(regop), 914 NameOfCPURegister(rm), 915 imm); 916 data += 2 + (*data == 0x6B ? 1 : 4); 917 } 918 break; 919 920 case 0xF6: 921 { int mod, regop, rm; 922 get_modrm(*(data+1), &mod, ®op, &rm); 923 if (mod == 3 && regop == eax) { 924 AppendToBuffer("test_b %s,%d", NameOfCPURegister(rm), *(data+2)); 925 } else { 926 UnimplementedInstruction(); 927 } 928 data += 3; 929 } 930 break; 931 932 case 0x81: // fall through 933 case 0x83: // 0x81 with sign extension bit set 934 data += PrintImmediateOp(data); 935 break; 936 937 case 0x0F: 938 { byte f0byte = *(data+1); 939 const char* f0mnem = F0Mnem(f0byte); 940 if (f0byte == 0xA2 || f0byte == 0x31) { 941 AppendToBuffer("%s", f0mnem); 942 data += 2; 943 } else if ((f0byte & 0xF0) == 0x80) { 944 data += JumpConditional(data, branch_hint); 945 } else if (f0byte == 0xBE || f0byte == 0xBF || f0byte == 0xB6 || 946 f0byte == 0xB7 || f0byte == 0xAF) { 947 data += 2; 948 data += PrintOperands(f0mnem, REG_OPER_OP_ORDER, data); 949 } else if ((f0byte & 0xF0) == 0x90) { 950 data += SetCC(data); 951 } else if ((f0byte & 0xF0) == 0x40) { 952 data += CMov(data); 953 } else { 954 data += 2; 955 if (f0byte == 0xAB || f0byte == 0xA5 || f0byte == 0xAD) { 956 // shrd, shld, bts 957 AppendToBuffer("%s ", f0mnem); 958 int mod, regop, rm; 959 get_modrm(*data, &mod, ®op, &rm); 960 data += PrintRightOperand(data); 961 if (f0byte == 0xAB) { 962 AppendToBuffer(",%s", NameOfCPURegister(regop)); 963 } else { 964 AppendToBuffer(",%s,cl", NameOfCPURegister(regop)); 965 } 966 } else { 967 UnimplementedInstruction(); 968 } 969 } 970 } 971 break; 972 973 case 0x8F: 974 { data++; 975 int mod, regop, rm; 976 get_modrm(*data, &mod, ®op, &rm); 977 if (regop == eax) { 978 AppendToBuffer("pop "); 979 data += PrintRightOperand(data); 980 } 981 } 982 break; 983 984 case 0xFF: 985 { data++; 986 int mod, regop, rm; 987 get_modrm(*data, &mod, ®op, &rm); 988 const char* mnem = NULL; 989 switch (regop) { 990 case esi: mnem = "push"; break; 991 case eax: mnem = "inc"; break; 992 case ecx: mnem = "dec"; break; 993 case edx: mnem = "call"; break; 994 case esp: mnem = "jmp"; break; 995 default: mnem = "???"; 996 } 997 AppendToBuffer("%s ", mnem); 998 data += PrintRightOperand(data); 999 } 1000 break; 1001 1002 case 0xC7: // imm32, fall through 1003 case 0xC6: // imm8 1004 { bool is_byte = *data == 0xC6; 1005 data++; 1006 AppendToBuffer("%s ", is_byte ? "mov_b" : "mov"); 1007 data += PrintRightOperand(data); 1008 int32_t imm = is_byte ? *data : *reinterpret_cast<int32_t*>(data); 1009 AppendToBuffer(",0x%x", imm); 1010 data += is_byte ? 1 : 4; 1011 } 1012 break; 1013 1014 case 0x80: 1015 { data++; 1016 int mod, regop, rm; 1017 get_modrm(*data, &mod, ®op, &rm); 1018 const char* mnem = NULL; 1019 switch (regop) { 1020 case 5: mnem = "subb"; break; 1021 case 7: mnem = "cmpb"; break; 1022 default: UnimplementedInstruction(); 1023 } 1024 AppendToBuffer("%s ", mnem); 1025 data += PrintRightOperand(data); 1026 int32_t imm = *data; 1027 AppendToBuffer(",0x%x", imm); 1028 data++; 1029 } 1030 break; 1031 1032 case 0x88: // 8bit, fall through 1033 case 0x89: // 32bit 1034 { bool is_byte = *data == 0x88; 1035 int mod, regop, rm; 1036 data++; 1037 get_modrm(*data, &mod, ®op, &rm); 1038 AppendToBuffer("%s ", is_byte ? "mov_b" : "mov"); 1039 data += PrintRightOperand(data); 1040 AppendToBuffer(",%s", NameOfCPURegister(regop)); 1041 } 1042 break; 1043 1044 case 0x66: // prefix 1045 data++; 1046 if (*data == 0x8B) { 1047 data++; 1048 data += PrintOperands("mov_w", REG_OPER_OP_ORDER, data); 1049 } else if (*data == 0x89) { 1050 data++; 1051 int mod, regop, rm; 1052 get_modrm(*data, &mod, ®op, &rm); 1053 AppendToBuffer("mov_w "); 1054 data += PrintRightOperand(data); 1055 AppendToBuffer(",%s", NameOfCPURegister(regop)); 1056 } else if (*data == 0x0F) { 1057 data++; 1058 if (*data == 0x2F) { 1059 data++; 1060 int mod, regop, rm; 1061 get_modrm(*data, &mod, ®op, &rm); 1062 AppendToBuffer("comisd %s,%s", 1063 NameOfXMMRegister(regop), 1064 NameOfXMMRegister(rm)); 1065 data++; 1066 } else if (*data == 0x57) { 1067 data++; 1068 int mod, regop, rm; 1069 get_modrm(*data, &mod, ®op, &rm); 1070 AppendToBuffer("xorpd %s,%s", 1071 NameOfXMMRegister(regop), 1072 NameOfXMMRegister(rm)); 1073 data++; 1074 } else if (*data == 0x6F) { 1075 data++; 1076 int mod, regop, rm; 1077 get_modrm(*data, &mod, ®op, &rm); 1078 AppendToBuffer("movdqa %s,", NameOfXMMRegister(regop)); 1079 data += PrintRightOperand(data); 1080 } else if (*data == 0x7F) { 1081 AppendToBuffer("movdqa "); 1082 data++; 1083 int mod, regop, rm; 1084 get_modrm(*data, &mod, ®op, &rm); 1085 data += PrintRightOperand(data); 1086 AppendToBuffer(",%s", NameOfXMMRegister(regop)); 1087 } else { 1088 UnimplementedInstruction(); 1089 } 1090 } else { 1091 UnimplementedInstruction(); 1092 } 1093 break; 1094 1095 case 0xFE: 1096 { data++; 1097 int mod, regop, rm; 1098 get_modrm(*data, &mod, ®op, &rm); 1099 if (mod == 3 && regop == ecx) { 1100 AppendToBuffer("dec_b %s", NameOfCPURegister(rm)); 1101 } else { 1102 UnimplementedInstruction(); 1103 } 1104 data++; 1105 } 1106 break; 1107 1108 case 0x68: 1109 AppendToBuffer("push 0x%x", *reinterpret_cast<int32_t*>(data+1)); 1110 data += 5; 1111 break; 1112 1113 case 0x6A: 1114 AppendToBuffer("push 0x%x", *reinterpret_cast<int8_t*>(data + 1)); 1115 data += 2; 1116 break; 1117 1118 case 0xA8: 1119 AppendToBuffer("test al,0x%x", *reinterpret_cast<uint8_t*>(data+1)); 1120 data += 2; 1121 break; 1122 1123 case 0x2C: 1124 AppendToBuffer("subb eax,0x%x", *reinterpret_cast<uint8_t*>(data+1)); 1125 data += 2; 1126 break; 1127 1128 case 0xA9: 1129 AppendToBuffer("test eax,0x%x", *reinterpret_cast<int32_t*>(data+1)); 1130 data += 5; 1131 break; 1132 1133 case 0xD1: // fall through 1134 case 0xD3: // fall through 1135 case 0xC1: 1136 data += D1D3C1Instruction(data); 1137 break; 1138 1139 case 0xD9: // fall through 1140 case 0xDA: // fall through 1141 case 0xDB: // fall through 1142 case 0xDC: // fall through 1143 case 0xDD: // fall through 1144 case 0xDE: // fall through 1145 case 0xDF: 1146 data += FPUInstruction(data); 1147 break; 1148 1149 case 0xEB: 1150 data += JumpShort(data); 1151 break; 1152 1153 case 0xF2: 1154 if (*(data+1) == 0x0F) { 1155 byte b2 = *(data+2); 1156 if (b2 == 0x11) { 1157 AppendToBuffer("movsd "); 1158 data += 3; 1159 int mod, regop, rm; 1160 get_modrm(*data, &mod, ®op, &rm); 1161 data += PrintRightOperand(data); 1162 AppendToBuffer(",%s", NameOfXMMRegister(regop)); 1163 } else if (b2 == 0x10) { 1164 data += 3; 1165 int mod, regop, rm; 1166 get_modrm(*data, &mod, ®op, &rm); 1167 AppendToBuffer("movsd %s,", NameOfXMMRegister(regop)); 1168 data += PrintRightOperand(data); 1169 } else { 1170 const char* mnem = "?"; 1171 switch (b2) { 1172 case 0x2A: mnem = "cvtsi2sd"; break; 1173 case 0x58: mnem = "addsd"; break; 1174 case 0x59: mnem = "mulsd"; break; 1175 case 0x5C: mnem = "subsd"; break; 1176 case 0x5E: mnem = "divsd"; break; 1177 } 1178 data += 3; 1179 int mod, regop, rm; 1180 get_modrm(*data, &mod, ®op, &rm); 1181 if (b2 == 0x2A) { 1182 AppendToBuffer("%s %s,", mnem, NameOfXMMRegister(regop)); 1183 data += PrintRightOperand(data); 1184 } else { 1185 AppendToBuffer("%s %s,%s", 1186 mnem, 1187 NameOfXMMRegister(regop), 1188 NameOfXMMRegister(rm)); 1189 data++; 1190 } 1191 } 1192 } else { 1193 UnimplementedInstruction(); 1194 } 1195 break; 1196 1197 case 0xF3: 1198 if (*(data+1) == 0x0F) { 1199 if (*(data+2) == 0x2C) { 1200 data += 3; 1201 data += PrintOperands("cvttss2si", REG_OPER_OP_ORDER, data); 1202 } else if (*(data+2) == 0x6F) { 1203 data += 3; 1204 int mod, regop, rm; 1205 get_modrm(*data, &mod, ®op, &rm); 1206 AppendToBuffer("movdqu %s,", NameOfXMMRegister(regop)); 1207 data += PrintRightOperand(data); 1208 } else if (*(data+2) == 0x7F) { 1209 AppendToBuffer("movdqu "); 1210 data += 3; 1211 int mod, regop, rm; 1212 get_modrm(*data, &mod, ®op, &rm); 1213 data += PrintRightOperand(data); 1214 AppendToBuffer(",%s", NameOfXMMRegister(regop)); 1215 } else { 1216 UnimplementedInstruction(); 1217 } 1218 } else if (*(data+1) == 0xA5) { 1219 data += 2; 1220 AppendToBuffer("rep_movs"); 1221 } else { 1222 UnimplementedInstruction(); 1223 } 1224 break; 1225 1226 case 0xF7: 1227 data += F7Instruction(data); 1228 break; 1229 1230 default: 1231 UnimplementedInstruction(); 1232 } 1233 } 1234 1235 if (tmp_buffer_pos_ < sizeof tmp_buffer_) { 1236 tmp_buffer_[tmp_buffer_pos_] = '\0'; 1237 } 1238 1239 int instr_len = data - instr; 1240 if (instr_len == 0) { 1241 printf("%02x", *data); 1242 } 1243 ASSERT(instr_len > 0); // Ensure progress. 1244 1245 int outp = 0; 1246 // Instruction bytes. 1247 for (byte* bp = instr; bp < data; bp++) { 1248 outp += v8::internal::OS::SNPrintF(out_buffer + outp, 1249 "%02x", 1250 *bp); 1251 } 1252 for (int i = 6 - instr_len; i >= 0; i--) { 1253 outp += v8::internal::OS::SNPrintF(out_buffer + outp, 1254 " "); 1255 } 1256 1257 outp += v8::internal::OS::SNPrintF(out_buffer + outp, 1258 " %s", 1259 tmp_buffer_.start()); 1260 return instr_len; 1261 } 1262 1263 1264 //------------------------------------------------------------------------------ 1265 1266 1267 static const char* cpu_regs[8] = { 1268 "eax", "ecx", "edx", "ebx", "esp", "ebp", "esi", "edi" 1269 }; 1270 1271 1272 static const char* byte_cpu_regs[8] = { 1273 "al", "cl", "dl", "bl", "ah", "ch", "dh", "bh" 1274 }; 1275 1276 1277 static const char* xmm_regs[8] = { 1278 "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5", "xmm6", "xmm7" 1279 }; 1280 1281 1282 const char* NameConverter::NameOfAddress(byte* addr) const { 1283 static v8::internal::EmbeddedVector<char, 32> tmp_buffer; 1284 v8::internal::OS::SNPrintF(tmp_buffer, "%p", addr); 1285 return tmp_buffer.start(); 1286 } 1287 1288 1289 const char* NameConverter::NameOfConstant(byte* addr) const { 1290 return NameOfAddress(addr); 1291 } 1292 1293 1294 const char* NameConverter::NameOfCPURegister(int reg) const { 1295 if (0 <= reg && reg < 8) return cpu_regs[reg]; 1296 return "noreg"; 1297 } 1298 1299 1300 const char* NameConverter::NameOfByteCPURegister(int reg) const { 1301 if (0 <= reg && reg < 8) return byte_cpu_regs[reg]; 1302 return "noreg"; 1303 } 1304 1305 1306 const char* NameConverter::NameOfXMMRegister(int reg) const { 1307 if (0 <= reg && reg < 8) return xmm_regs[reg]; 1308 return "noxmmreg"; 1309 } 1310 1311 1312 const char* NameConverter::NameInCode(byte* addr) const { 1313 // IA32 does not embed debug strings at the moment. 1314 UNREACHABLE(); 1315 return ""; 1316 } 1317 1318 1319 //------------------------------------------------------------------------------ 1320 1321 Disassembler::Disassembler(const NameConverter& converter) 1322 : converter_(converter) {} 1323 1324 1325 Disassembler::~Disassembler() {} 1326 1327 1328 int Disassembler::InstructionDecode(v8::internal::Vector<char> buffer, 1329 byte* instruction) { 1330 DisassemblerIA32 d(converter_, false /*do not crash if unimplemented*/); 1331 return d.InstructionDecode(buffer, instruction); 1332 } 1333 1334 1335 // The IA-32 assembler does not currently use constant pools. 1336 int Disassembler::ConstantPoolSizeAt(byte* instruction) { return -1; } 1337 1338 1339 /*static*/ void Disassembler::Disassemble(FILE* f, byte* begin, byte* end) { 1340 NameConverter converter; 1341 Disassembler d(converter); 1342 for (byte* pc = begin; pc < end;) { 1343 v8::internal::EmbeddedVector<char, 128> buffer; 1344 buffer[0] = '\0'; 1345 byte* prev_pc = pc; 1346 pc += d.InstructionDecode(buffer, pc); 1347 fprintf(f, "%p", prev_pc); 1348 fprintf(f, " "); 1349 1350 for (byte* bp = prev_pc; bp < pc; bp++) { 1351 fprintf(f, "%02x", *bp); 1352 } 1353 for (int i = 6 - (pc - prev_pc); i >= 0; i--) { 1354 fprintf(f, " "); 1355 } 1356 fprintf(f, " %s\n", buffer.start()); 1357 } 1358 } 1359 1360 1361 } // namespace disasm 1362