// Copyright 2011 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <assert.h>
#include <stdarg.h>
#include <stdio.h>
#include "src/v8.h"
#if V8_TARGET_ARCH_X64
#include "src/base/lazy-instance.h"
#include "src/disasm.h"
namespace disasm {
enum OperandType {
UNSET_OP_ORDER = 0,
// Operand size decides between 16, 32 and 64 bit operands.
REG_OPER_OP_ORDER = 1, // Register destination, operand source.
OPER_REG_OP_ORDER = 2, // Operand destination, register source.
// Fixed 8-bit operands.
BYTE_SIZE_OPERAND_FLAG = 4,
BYTE_REG_OPER_OP_ORDER = REG_OPER_OP_ORDER | BYTE_SIZE_OPERAND_FLAG,
BYTE_OPER_REG_OP_ORDER = OPER_REG_OP_ORDER | BYTE_SIZE_OPERAND_FLAG
};
//------------------------------------------------------------------
// Tables
//------------------------------------------------------------------
struct ByteMnemonic {
int b; // -1 terminates, otherwise must be in range (0..255)
OperandType op_order_;
const char* mnem;
};
static const ByteMnemonic two_operands_instr[] = {
{ 0x00, BYTE_OPER_REG_OP_ORDER, "add" },
{ 0x01, OPER_REG_OP_ORDER, "add" },
{ 0x02, BYTE_REG_OPER_OP_ORDER, "add" },
{ 0x03, REG_OPER_OP_ORDER, "add" },
{ 0x08, BYTE_OPER_REG_OP_ORDER, "or" },
{ 0x09, OPER_REG_OP_ORDER, "or" },
{ 0x0A, BYTE_REG_OPER_OP_ORDER, "or" },
{ 0x0B, REG_OPER_OP_ORDER, "or" },
{ 0x10, BYTE_OPER_REG_OP_ORDER, "adc" },
{ 0x11, OPER_REG_OP_ORDER, "adc" },
{ 0x12, BYTE_REG_OPER_OP_ORDER, "adc" },
{ 0x13, REG_OPER_OP_ORDER, "adc" },
{ 0x18, BYTE_OPER_REG_OP_ORDER, "sbb" },
{ 0x19, OPER_REG_OP_ORDER, "sbb" },
{ 0x1A, BYTE_REG_OPER_OP_ORDER, "sbb" },
{ 0x1B, REG_OPER_OP_ORDER, "sbb" },
{ 0x20, BYTE_OPER_REG_OP_ORDER, "and" },
{ 0x21, OPER_REG_OP_ORDER, "and" },
{ 0x22, BYTE_REG_OPER_OP_ORDER, "and" },
{ 0x23, REG_OPER_OP_ORDER, "and" },
{ 0x28, BYTE_OPER_REG_OP_ORDER, "sub" },
{ 0x29, OPER_REG_OP_ORDER, "sub" },
{ 0x2A, BYTE_REG_OPER_OP_ORDER, "sub" },
{ 0x2B, REG_OPER_OP_ORDER, "sub" },
{ 0x30, BYTE_OPER_REG_OP_ORDER, "xor" },
{ 0x31, OPER_REG_OP_ORDER, "xor" },
{ 0x32, BYTE_REG_OPER_OP_ORDER, "xor" },
{ 0x33, REG_OPER_OP_ORDER, "xor" },
{ 0x38, BYTE_OPER_REG_OP_ORDER, "cmp" },
{ 0x39, OPER_REG_OP_ORDER, "cmp" },
{ 0x3A, BYTE_REG_OPER_OP_ORDER, "cmp" },
{ 0x3B, REG_OPER_OP_ORDER, "cmp" },
{ 0x63, REG_OPER_OP_ORDER, "movsxl" },
{ 0x84, BYTE_REG_OPER_OP_ORDER, "test" },
{ 0x85, REG_OPER_OP_ORDER, "test" },
{ 0x86, BYTE_REG_OPER_OP_ORDER, "xchg" },
{ 0x87, REG_OPER_OP_ORDER, "xchg" },
{ 0x88, BYTE_OPER_REG_OP_ORDER, "mov" },
{ 0x89, OPER_REG_OP_ORDER, "mov" },
{ 0x8A, BYTE_REG_OPER_OP_ORDER, "mov" },
{ 0x8B, REG_OPER_OP_ORDER, "mov" },
{ 0x8D, REG_OPER_OP_ORDER, "lea" },
{ -1, UNSET_OP_ORDER, "" }
};
static const ByteMnemonic zero_operands_instr[] = {
{ 0xC3, UNSET_OP_ORDER, "ret" },
{ 0xC9, UNSET_OP_ORDER, "leave" },
{ 0xF4, UNSET_OP_ORDER, "hlt" },
{ 0xFC, UNSET_OP_ORDER, "cld" },
{ 0xCC, UNSET_OP_ORDER, "int3" },
{ 0x60, UNSET_OP_ORDER, "pushad" },
{ 0x61, UNSET_OP_ORDER, "popad" },
{ 0x9C, UNSET_OP_ORDER, "pushfd" },
{ 0x9D, UNSET_OP_ORDER, "popfd" },
{ 0x9E, UNSET_OP_ORDER, "sahf" },
{ 0x99, UNSET_OP_ORDER, "cdq" },
{ 0x9B, UNSET_OP_ORDER, "fwait" },
{ 0xA4, UNSET_OP_ORDER, "movs" },
{ 0xA5, UNSET_OP_ORDER, "movs" },
{ 0xA6, UNSET_OP_ORDER, "cmps" },
{ 0xA7, UNSET_OP_ORDER, "cmps" },
{ -1, UNSET_OP_ORDER, "" }
};
static const ByteMnemonic call_jump_instr[] = {
{ 0xE8, UNSET_OP_ORDER, "call" },
{ 0xE9, UNSET_OP_ORDER, "jmp" },
{ -1, UNSET_OP_ORDER, "" }
};
static const ByteMnemonic short_immediate_instr[] = {
{ 0x05, UNSET_OP_ORDER, "add" },
{ 0x0D, UNSET_OP_ORDER, "or" },
{ 0x15, UNSET_OP_ORDER, "adc" },
{ 0x1D, UNSET_OP_ORDER, "sbb" },
{ 0x25, UNSET_OP_ORDER, "and" },
{ 0x2D, UNSET_OP_ORDER, "sub" },
{ 0x35, UNSET_OP_ORDER, "xor" },
{ 0x3D, UNSET_OP_ORDER, "cmp" },
{ -1, UNSET_OP_ORDER, "" }
};
static const char* const conditional_code_suffix[] = {
"o", "no", "c", "nc", "z", "nz", "na", "a",
"s", "ns", "pe", "po", "l", "ge", "le", "g"
};
enum InstructionType {
NO_INSTR,
ZERO_OPERANDS_INSTR,
TWO_OPERANDS_INSTR,
JUMP_CONDITIONAL_SHORT_INSTR,
REGISTER_INSTR,
PUSHPOP_INSTR, // Has implicit 64-bit operand size.
MOVE_REG_INSTR,
CALL_JUMP_INSTR,
SHORT_IMMEDIATE_INSTR
};
enum Prefixes {
ESCAPE_PREFIX = 0x0F,
OPERAND_SIZE_OVERRIDE_PREFIX = 0x66,
ADDRESS_SIZE_OVERRIDE_PREFIX = 0x67,
REPNE_PREFIX = 0xF2,
REP_PREFIX = 0xF3,
REPEQ_PREFIX = REP_PREFIX
};
struct InstructionDesc {
const char* mnem;
InstructionType type;
OperandType op_order_;
bool byte_size_operation; // Fixed 8-bit operation.
};
class InstructionTable {
public:
InstructionTable();
const InstructionDesc& Get(byte x) const {
return instructions_[x];
}
private:
InstructionDesc instructions_[256];
void Clear();
void Init();
void CopyTable(const ByteMnemonic bm[], InstructionType type);
void SetTableRange(InstructionType type, byte start, byte end, bool byte_size,
const char* mnem);
void AddJumpConditionalShort();
};
InstructionTable::InstructionTable() {
Clear();
Init();
}
void InstructionTable::Clear() {
for (int i = 0; i < 256; i++) {
instructions_[i].mnem = "(bad)";
instructions_[i].type = NO_INSTR;
instructions_[i].op_order_ = UNSET_OP_ORDER;
instructions_[i].byte_size_operation = false;
}
}
void InstructionTable::Init() {
CopyTable(two_operands_instr, TWO_OPERANDS_INSTR);
CopyTable(zero_operands_instr, ZERO_OPERANDS_INSTR);
CopyTable(call_jump_instr, CALL_JUMP_INSTR);
CopyTable(short_immediate_instr, SHORT_IMMEDIATE_INSTR);
AddJumpConditionalShort();
SetTableRange(PUSHPOP_INSTR, 0x50, 0x57, false, "push");
SetTableRange(PUSHPOP_INSTR, 0x58, 0x5F, false, "pop");
SetTableRange(MOVE_REG_INSTR, 0xB8, 0xBF, false, "mov");
}
void InstructionTable::CopyTable(const ByteMnemonic bm[],
InstructionType type) {
for (int i = 0; bm[i].b >= 0; i++) {
InstructionDesc* id = &instructions_[bm[i].b];
id->mnem = bm[i].mnem;
OperandType op_order = bm[i].op_order_;
id->op_order_ =
static_cast<OperandType>(op_order & ~BYTE_SIZE_OPERAND_FLAG);
DCHECK_EQ(NO_INSTR, id->type); // Information not already entered
id->type = type;
id->byte_size_operation = ((op_order & BYTE_SIZE_OPERAND_FLAG) != 0);
}
}
void InstructionTable::SetTableRange(InstructionType type,
byte start,
byte end,
bool byte_size,
const char* mnem) {
for (byte b = start; b <= end; b++) {
InstructionDesc* id = &instructions_[b];
DCHECK_EQ(NO_INSTR, id->type); // Information not already entered
id->mnem = mnem;
id->type = type;
id->byte_size_operation = byte_size;
}
}
void InstructionTable::AddJumpConditionalShort() {
for (byte b = 0x70; b <= 0x7F; b++) {
InstructionDesc* id = &instructions_[b];
DCHECK_EQ(NO_INSTR, id->type); // Information not already entered
id->mnem = NULL; // Computed depending on condition code.
id->type = JUMP_CONDITIONAL_SHORT_INSTR;
}
}
static v8::base::LazyInstance<InstructionTable>::type instruction_table =
LAZY_INSTANCE_INITIALIZER;
static InstructionDesc cmov_instructions[16] = {
{"cmovo", TWO_OPERANDS_INSTR, REG_OPER_OP_ORDER, false},
{"cmovno", TWO_OPERANDS_INSTR, REG_OPER_OP_ORDER, false},
{"cmovc", TWO_OPERANDS_INSTR, REG_OPER_OP_ORDER, false},
{"cmovnc", TWO_OPERANDS_INSTR, REG_OPER_OP_ORDER, false},
{"cmovz", TWO_OPERANDS_INSTR, REG_OPER_OP_ORDER, false},
{"cmovnz", TWO_OPERANDS_INSTR, REG_OPER_OP_ORDER, false},
{"cmovna", TWO_OPERANDS_INSTR, REG_OPER_OP_ORDER, false},
{"cmova", TWO_OPERANDS_INSTR, REG_OPER_OP_ORDER, false},
{"cmovs", TWO_OPERANDS_INSTR, REG_OPER_OP_ORDER, false},
{"cmovns", TWO_OPERANDS_INSTR, REG_OPER_OP_ORDER, false},
{"cmovpe", TWO_OPERANDS_INSTR, REG_OPER_OP_ORDER, false},
{"cmovpo", TWO_OPERANDS_INSTR, REG_OPER_OP_ORDER, false},
{"cmovl", TWO_OPERANDS_INSTR, REG_OPER_OP_ORDER, false},
{"cmovge", TWO_OPERANDS_INSTR, REG_OPER_OP_ORDER, false},
{"cmovle", TWO_OPERANDS_INSTR, REG_OPER_OP_ORDER, false},
{"cmovg", TWO_OPERANDS_INSTR, REG_OPER_OP_ORDER, false}
};
//------------------------------------------------------------------------------
// DisassemblerX64 implementation.
enum UnimplementedOpcodeAction {
CONTINUE_ON_UNIMPLEMENTED_OPCODE,
ABORT_ON_UNIMPLEMENTED_OPCODE
};
// A new DisassemblerX64 object is created to disassemble each instruction.
// The object can only disassemble a single instruction.
class DisassemblerX64 {
public:
DisassemblerX64(const NameConverter& converter,
UnimplementedOpcodeAction unimplemented_action =
ABORT_ON_UNIMPLEMENTED_OPCODE)
: converter_(converter),
tmp_buffer_pos_(0),
abort_on_unimplemented_(
unimplemented_action == ABORT_ON_UNIMPLEMENTED_OPCODE),
rex_(0),
operand_size_(0),
group_1_prefix_(0),
byte_size_operand_(false),
instruction_table_(instruction_table.Pointer()) {
tmp_buffer_[0] = '\0';
}
virtual ~DisassemblerX64() {
}
// Writes one disassembled instruction into 'buffer' (0-terminated).
// Returns the length of the disassembled machine instruction in bytes.
int InstructionDecode(v8::internal::Vector<char> buffer, byte* instruction);
private:
enum OperandSize {
OPERAND_BYTE_SIZE = 0,
OPERAND_WORD_SIZE = 1,
OPERAND_DOUBLEWORD_SIZE = 2,
OPERAND_QUADWORD_SIZE = 3
};
const NameConverter& converter_;
v8::internal::EmbeddedVector<char, 128> tmp_buffer_;
unsigned int tmp_buffer_pos_;
bool abort_on_unimplemented_;
// Prefixes parsed
byte rex_;
byte operand_size_; // 0x66 or (if no group 3 prefix is present) 0x0.
byte group_1_prefix_; // 0xF2, 0xF3, or (if no group 1 prefix is present) 0.
// Byte size operand override.
bool byte_size_operand_;
const InstructionTable* const instruction_table_;
void setRex(byte rex) {
DCHECK_EQ(0x40, rex & 0xF0);
rex_ = rex;
}
bool rex() { return rex_ != 0; }
bool rex_b() { return (rex_ & 0x01) != 0; }
// Actual number of base register given the low bits and the rex.b state.
int base_reg(int low_bits) { return low_bits | ((rex_ & 0x01) << 3); }
bool rex_x() { return (rex_ & 0x02) != 0; }
bool rex_r() { return (rex_ & 0x04) != 0; }
bool rex_w() { return (rex_ & 0x08) != 0; }
OperandSize operand_size() {
if (byte_size_operand_) return OPERAND_BYTE_SIZE;
if (rex_w()) return OPERAND_QUADWORD_SIZE;
if (operand_size_ != 0) return OPERAND_WORD_SIZE;
return OPERAND_DOUBLEWORD_SIZE;
}
char operand_size_code() {
return "bwlq"[operand_size()];
}
const char* NameOfCPURegister(int reg) const {
return converter_.NameOfCPURegister(reg);
}
const char* NameOfByteCPURegister(int reg) const {
return converter_.NameOfByteCPURegister(reg);
}
const char* NameOfXMMRegister(int reg) const {
return converter_.NameOfXMMRegister(reg);
}
const char* NameOfAddress(byte* addr) const {
return converter_.NameOfAddress(addr);
}
// Disassembler helper functions.
void get_modrm(byte data,
int* mod,
int* regop,
int* rm) {
*mod = (data >> 6) & 3;
*regop = ((data & 0x38) >> 3) | (rex_r() ? 8 : 0);
*rm = (data & 7) | (rex_b() ? 8 : 0);
}
void get_sib(byte data,
int* scale,
int* index,
int* base) {
*scale = (data >> 6) & 3;
*index = ((data >> 3) & 7) | (rex_x() ? 8 : 0);
*base = (data & 7) | (rex_b() ? 8 : 0);
}
typedef const char* (DisassemblerX64::*RegisterNameMapping)(int reg) const;
int PrintRightOperandHelper(byte* modrmp,
RegisterNameMapping register_name);
int PrintRightOperand(byte* modrmp);
int PrintRightByteOperand(byte* modrmp);
int PrintRightXMMOperand(byte* modrmp);
int PrintOperands(const char* mnem,
OperandType op_order,
byte* data);
int PrintImmediate(byte* data, OperandSize size);
int PrintImmediateOp(byte* data);
const char* TwoByteMnemonic(byte opcode);
int TwoByteOpcodeInstruction(byte* data);
int F6F7Instruction(byte* data);
int ShiftInstruction(byte* data);
int JumpShort(byte* data);
int JumpConditional(byte* data);
int JumpConditionalShort(byte* data);
int SetCC(byte* data);
int FPUInstruction(byte* data);
int MemoryFPUInstruction(int escape_opcode, int regop, byte* modrm_start);
int RegisterFPUInstruction(int escape_opcode, byte modrm_byte);
void AppendToBuffer(const char* format, ...);
void UnimplementedInstruction() {
if (abort_on_unimplemented_) {
CHECK(false);
} else {
AppendToBuffer("'Unimplemented Instruction'");
}
}
};
void DisassemblerX64::AppendToBuffer(const char* format, ...) {
v8::internal::Vector<char> buf = tmp_buffer_ + tmp_buffer_pos_;
va_list args;
va_start(args, format);
int result = v8::internal::VSNPrintF(buf, format, args);
va_end(args);
tmp_buffer_pos_ += result;
}
int DisassemblerX64::PrintRightOperandHelper(
byte* modrmp,
RegisterNameMapping direct_register_name) {
int mod, regop, rm;
get_modrm(*modrmp, &mod, ®op, &rm);
RegisterNameMapping register_name = (mod == 3) ? direct_register_name :
&DisassemblerX64::NameOfCPURegister;
switch (mod) {
case 0:
if ((rm & 7) == 5) {
int32_t disp = *reinterpret_cast<int32_t*>(modrmp + 1);
AppendToBuffer("[0x%x]", disp);
return 5;
} else if ((rm & 7) == 4) {
// Codes for SIB byte.
byte sib = *(modrmp + 1);
int scale, index, base;
get_sib(sib, &scale, &index, &base);
if (index == 4 && (base & 7) == 4 && scale == 0 /*times_1*/) {
// index == rsp means no index. Only use sib byte with no index for
// rsp and r12 base.
AppendToBuffer("[%s]", NameOfCPURegister(base));
return 2;
} else if (base == 5) {
// base == rbp means no base register (when mod == 0).
int32_t disp = *reinterpret_cast<int32_t*>(modrmp + 2);
AppendToBuffer("[%s*%d%s0x%x]",
NameOfCPURegister(index),
1 << scale,
disp < 0 ? "-" : "+",
disp < 0 ? -disp : disp);
return 6;
} else if (index != 4 && base != 5) {
// [base+index*scale]
AppendToBuffer("[%s+%s*%d]",
NameOfCPURegister(base),
NameOfCPURegister(index),
1 << scale);
return 2;
} else {
UnimplementedInstruction();
return 1;
}
} else {
AppendToBuffer("[%s]", NameOfCPURegister(rm));
return 1;
}
break;
case 1: // fall through
case 2:
if ((rm & 7) == 4) {
byte sib = *(modrmp + 1);
int scale, index, base;
get_sib(sib, &scale, &index, &base);
int disp = (mod == 2) ? *reinterpret_cast<int32_t*>(modrmp + 2)
: *reinterpret_cast<int8_t*>(modrmp + 2);
if (index == 4 && (base & 7) == 4 && scale == 0 /*times_1*/) {
AppendToBuffer("[%s%s0x%x]",
NameOfCPURegister(base),
disp < 0 ? "-" : "+",
disp < 0 ? -disp : disp);
} else {
AppendToBuffer("[%s+%s*%d%s0x%x]",
NameOfCPURegister(base),
NameOfCPURegister(index),
1 << scale,
disp < 0 ? "-" : "+",
disp < 0 ? -disp : disp);
}
return mod == 2 ? 6 : 3;
} else {
// No sib.
int disp = (mod == 2) ? *reinterpret_cast<int32_t*>(modrmp + 1)
: *reinterpret_cast<int8_t*>(modrmp + 1);
AppendToBuffer("[%s%s0x%x]",
NameOfCPURegister(rm),
disp < 0 ? "-" : "+",
disp < 0 ? -disp : disp);
return (mod == 2) ? 5 : 2;
}
break;
case 3:
AppendToBuffer("%s", (this->*register_name)(rm));
return 1;
default:
UnimplementedInstruction();
return 1;
}
UNREACHABLE();
}
int DisassemblerX64::PrintImmediate(byte* data, OperandSize size) {
int64_t value;
int count;
switch (size) {
case OPERAND_BYTE_SIZE:
value = *data;
count = 1;
break;
case OPERAND_WORD_SIZE:
value = *reinterpret_cast<int16_t*>(data);
count = 2;
break;
case OPERAND_DOUBLEWORD_SIZE:
value = *reinterpret_cast<uint32_t*>(data);
count = 4;
break;
case OPERAND_QUADWORD_SIZE:
value = *reinterpret_cast<int32_t*>(data);
count = 4;
break;
default:
UNREACHABLE();
value = 0; // Initialize variables on all paths to satisfy the compiler.
count = 0;
}
AppendToBuffer("%" V8_PTR_PREFIX "x", value);
return count;
}
int DisassemblerX64::PrintRightOperand(byte* modrmp) {
return PrintRightOperandHelper(modrmp,
&DisassemblerX64::NameOfCPURegister);
}
int DisassemblerX64::PrintRightByteOperand(byte* modrmp) {
return PrintRightOperandHelper(modrmp,
&DisassemblerX64::NameOfByteCPURegister);
}
int DisassemblerX64::PrintRightXMMOperand(byte* modrmp) {
return PrintRightOperandHelper(modrmp,
&DisassemblerX64::NameOfXMMRegister);
}
// Returns number of bytes used including the current *data.
// Writes instruction's mnemonic, left and right operands to 'tmp_buffer_'.
int DisassemblerX64::PrintOperands(const char* mnem,
OperandType op_order,
byte* data) {
byte modrm = *data;
int mod, regop, rm;
get_modrm(modrm, &mod, ®op, &rm);
int advance = 0;
const char* register_name =
byte_size_operand_ ? NameOfByteCPURegister(regop)
: NameOfCPURegister(regop);
switch (op_order) {
case REG_OPER_OP_ORDER: {
AppendToBuffer("%s%c %s,",
mnem,
operand_size_code(),
register_name);
advance = byte_size_operand_ ? PrintRightByteOperand(data)
: PrintRightOperand(data);
break;
}
case OPER_REG_OP_ORDER: {
AppendToBuffer("%s%c ", mnem, operand_size_code());
advance = byte_size_operand_ ? PrintRightByteOperand(data)
: PrintRightOperand(data);
AppendToBuffer(",%s", register_name);
break;
}
default:
UNREACHABLE();
break;
}
return advance;
}
// Returns number of bytes used by machine instruction, including *data byte.
// Writes immediate instructions to 'tmp_buffer_'.
int DisassemblerX64::PrintImmediateOp(byte* data) {
bool byte_size_immediate = (*data & 0x02) != 0;
byte modrm = *(data + 1);
int mod, regop, rm;
get_modrm(modrm, &mod, ®op, &rm);
const char* mnem = "Imm???";
switch (regop) {
case 0:
mnem = "add";
break;
case 1:
mnem = "or";
break;
case 2:
mnem = "adc";
break;
case 3:
mnem = "sbb";
break;
case 4:
mnem = "and";
break;
case 5:
mnem = "sub";
break;
case 6:
mnem = "xor";
break;
case 7:
mnem = "cmp";
break;
default:
UnimplementedInstruction();
}
AppendToBuffer("%s%c ", mnem, operand_size_code());
int count = PrintRightOperand(data + 1);
AppendToBuffer(",0x");
OperandSize immediate_size =
byte_size_immediate ? OPERAND_BYTE_SIZE : operand_size();
count += PrintImmediate(data + 1 + count, immediate_size);
return 1 + count;
}
// Returns number of bytes used, including *data.
int DisassemblerX64::F6F7Instruction(byte* data) {
DCHECK(*data == 0xF7 || *data == 0xF6);
byte modrm = *(data + 1);
int mod, regop, rm;
get_modrm(modrm, &mod, ®op, &rm);
if (mod == 3 && regop != 0) {
const char* mnem = NULL;
switch (regop) {
case 2:
mnem = "not";
break;
case 3:
mnem = "neg";
break;
case 4:
mnem = "mul";
break;
case 5:
mnem = "imul";
break;
case 6:
mnem = "div";
break;
case 7:
mnem = "idiv";
break;
default:
UnimplementedInstruction();
}
AppendToBuffer("%s%c %s",
mnem,
operand_size_code(),
NameOfCPURegister(rm));
return 2;
} else if (regop == 0) {
AppendToBuffer("test%c ", operand_size_code());
int count = PrintRightOperand(data + 1); // Use name of 64-bit register.
AppendToBuffer(",0x");
count += PrintImmediate(data + 1 + count, operand_size());
return 1 + count;
} else {
UnimplementedInstruction();
return 2;
}
}
int DisassemblerX64::ShiftInstruction(byte* data) {
byte op = *data & (~1);
if (op != 0xD0 && op != 0xD2 && op != 0xC0) {
UnimplementedInstruction();
return 1;
}
byte modrm = *(data + 1);
int mod, regop, rm;
get_modrm(modrm, &mod, ®op, &rm);
regop &= 0x7; // The REX.R bit does not affect the operation.
int imm8 = -1;
int num_bytes = 2;
if (mod != 3) {
UnimplementedInstruction();
return num_bytes;
}
const char* mnem = NULL;
switch (regop) {
case 0:
mnem = "rol";
break;
case 1:
mnem = "ror";
break;
case 2:
mnem = "rcl";
break;
case 3:
mnem = "rcr";
break;
case 4:
mnem = "shl";
break;
case 5:
mnem = "shr";
break;
case 7:
mnem = "sar";
break;
default:
UnimplementedInstruction();
return num_bytes;
}
DCHECK_NE(NULL, mnem);
if (op == 0xD0) {
imm8 = 1;
} else if (op == 0xC0) {
imm8 = *(data + 2);
num_bytes = 3;
}
AppendToBuffer("%s%c %s,",
mnem,
operand_size_code(),
byte_size_operand_ ? NameOfByteCPURegister(rm)
: NameOfCPURegister(rm));
if (op == 0xD2) {
AppendToBuffer("cl");
} else {
AppendToBuffer("%d", imm8);
}
return num_bytes;
}
// Returns number of bytes used, including *data.
int DisassemblerX64::JumpShort(byte* data) {
DCHECK_EQ(0xEB, *data);
byte b = *(data + 1);
byte* dest = data + static_cast<int8_t>(b) + 2;
AppendToBuffer("jmp %s", NameOfAddress(dest));
return 2;
}
// Returns number of bytes used, including *data.
int DisassemblerX64::JumpConditional(byte* data) {
DCHECK_EQ(0x0F, *data);
byte cond = *(data + 1) & 0x0F;
byte* dest = data + *reinterpret_cast<int32_t*>(data + 2) + 6;
const char* mnem = conditional_code_suffix[cond];
AppendToBuffer("j%s %s", mnem, NameOfAddress(dest));
return 6; // includes 0x0F
}
// Returns number of bytes used, including *data.
int DisassemblerX64::JumpConditionalShort(byte* data) {
byte cond = *data & 0x0F;
byte b = *(data + 1);
byte* dest = data + static_cast<int8_t>(b) + 2;
const char* mnem = conditional_code_suffix[cond];
AppendToBuffer("j%s %s", mnem, NameOfAddress(dest));
return 2;
}
// Returns number of bytes used, including *data.
int DisassemblerX64::SetCC(byte* data) {
DCHECK_EQ(0x0F, *data);
byte cond = *(data + 1) & 0x0F;
const char* mnem = conditional_code_suffix[cond];
AppendToBuffer("set%s%c ", mnem, operand_size_code());
PrintRightByteOperand(data + 2);
return 3; // includes 0x0F
}
// Returns number of bytes used, including *data.
int DisassemblerX64::FPUInstruction(byte* data) {
byte escape_opcode = *data;
DCHECK_EQ(0xD8, escape_opcode & 0xF8);
byte modrm_byte = *(data+1);
if (modrm_byte >= 0xC0) {
return RegisterFPUInstruction(escape_opcode, modrm_byte);
} else {
return MemoryFPUInstruction(escape_opcode, modrm_byte, data+1);
}
}
int DisassemblerX64::MemoryFPUInstruction(int escape_opcode,
int modrm_byte,
byte* modrm_start) {
const char* mnem = "?";
int regop = (modrm_byte >> 3) & 0x7; // reg/op field of modrm byte.
switch (escape_opcode) {
case 0xD9: switch (regop) {
case 0: mnem = "fld_s"; break;
case 3: mnem = "fstp_s"; break;
case 7: mnem = "fstcw"; break;
default: UnimplementedInstruction();
}
break;
case 0xDB: switch (regop) {
case 0: mnem = "fild_s"; break;
case 1: mnem = "fisttp_s"; break;
case 2: mnem = "fist_s"; break;
case 3: mnem = "fistp_s"; break;
default: UnimplementedInstruction();
}
break;
case 0xDD: switch (regop) {
case 0: mnem = "fld_d"; break;
case 3: mnem = "fstp_d"; break;
default: UnimplementedInstruction();
}
break;
case 0xDF: switch (regop) {
case 5: mnem = "fild_d"; break;
case 7: mnem = "fistp_d"; break;
default: UnimplementedInstruction();
}
break;
default: UnimplementedInstruction();
}
AppendToBuffer("%s ", mnem);
int count = PrintRightOperand(modrm_start);
return count + 1;
}
int DisassemblerX64::RegisterFPUInstruction(int escape_opcode,
byte modrm_byte) {
bool has_register = false; // Is the FPU register encoded in modrm_byte?
const char* mnem = "?";
switch (escape_opcode) {
case 0xD8:
UnimplementedInstruction();
break;
case 0xD9:
switch (modrm_byte & 0xF8) {
case 0xC0:
mnem = "fld";
has_register = true;
break;
case 0xC8:
mnem = "fxch";
has_register = true;
break;
default:
switch (modrm_byte) {
case 0xE0: mnem = "fchs"; break;
case 0xE1: mnem = "fabs"; break;
case 0xE3: mnem = "fninit"; break;
case 0xE4: mnem = "ftst"; break;
case 0xE8: mnem = "fld1"; break;
case 0xEB: mnem = "fldpi"; break;
case 0xED: mnem = "fldln2"; break;
case 0xEE: mnem = "fldz"; break;
case 0xF0: mnem = "f2xm1"; break;
case 0xF1: mnem = "fyl2x"; break;
case 0xF2: mnem = "fptan"; break;
case 0xF5: mnem = "fprem1"; break;
case 0xF7: mnem = "fincstp"; break;
case 0xF8: mnem = "fprem"; break;
case 0xFC: mnem = "frndint"; break;
case 0xFD: mnem = "fscale"; break;
case 0xFE: mnem = "fsin"; break;
case 0xFF: mnem = "fcos"; break;
default: UnimplementedInstruction();
}
}
break;
case 0xDA:
if (modrm_byte == 0xE9) {
mnem = "fucompp";
} else {
UnimplementedInstruction();
}
break;
case 0xDB:
if ((modrm_byte & 0xF8) == 0xE8) {
mnem = "fucomi";
has_register = true;
} else if (modrm_byte == 0xE2) {
mnem = "fclex";
} else if (modrm_byte == 0xE3) {
mnem = "fninit";
} else {
UnimplementedInstruction();
}
break;
case 0xDC:
has_register = true;
switch (modrm_byte & 0xF8) {
case 0xC0: mnem = "fadd"; break;
case 0xE8: mnem = "fsub"; break;
case 0xC8: mnem = "fmul"; break;
case 0xF8: mnem = "fdiv"; break;
default: UnimplementedInstruction();
}
break;
case 0xDD:
has_register = true;
switch (modrm_byte & 0xF8) {
case 0xC0: mnem = "ffree"; break;
case 0xD8: mnem = "fstp"; break;
default: UnimplementedInstruction();
}
break;
case 0xDE:
if (modrm_byte == 0xD9) {
mnem = "fcompp";
} else {
has_register = true;
switch (modrm_byte & 0xF8) {
case 0xC0: mnem = "faddp"; break;
case 0xE8: mnem = "fsubp"; break;
case 0xC8: mnem = "fmulp"; break;
case 0xF8: mnem = "fdivp"; break;
default: UnimplementedInstruction();
}
}
break;
case 0xDF:
if (modrm_byte == 0xE0) {
mnem = "fnstsw_ax";
} else if ((modrm_byte & 0xF8) == 0xE8) {
mnem = "fucomip";
has_register = true;
}
break;
default: UnimplementedInstruction();
}
if (has_register) {
AppendToBuffer("%s st%d", mnem, modrm_byte & 0x7);
} else {
AppendToBuffer("%s", mnem);
}
return 2;
}
// Handle all two-byte opcodes, which start with 0x0F.
// These instructions may be affected by an 0x66, 0xF2, or 0xF3 prefix.
// We do not use any three-byte opcodes, which start with 0x0F38 or 0x0F3A.
int DisassemblerX64::TwoByteOpcodeInstruction(byte* data) {
byte opcode = *(data + 1);
byte* current = data + 2;
// At return, "current" points to the start of the next instruction.
const char* mnemonic = TwoByteMnemonic(opcode);
if (operand_size_ == 0x66) {
// 0x66 0x0F prefix.
int mod, regop, rm;
if (opcode == 0x3A) {
byte third_byte = *current;
current = data + 3;
if (third_byte == 0x17) {
get_modrm(*current, &mod, ®op, &rm);
AppendToBuffer("extractps "); // reg/m32, xmm, imm8
current += PrintRightOperand(current);
AppendToBuffer(",%s,%d", NameOfXMMRegister(regop), (*current) & 3);
current += 1;
} else if (third_byte == 0x0b) {
get_modrm(*current, &mod, ®op, &rm);
// roundsd xmm, xmm/m64, imm8
AppendToBuffer("roundsd %s,", NameOfXMMRegister(regop));
current += PrintRightXMMOperand(current);
AppendToBuffer(",%d", (*current) & 3);
current += 1;
} else {
UnimplementedInstruction();
}
} else {
get_modrm(*current, &mod, ®op, &rm);
if (opcode == 0x1f) {
current++;
if (rm == 4) { // SIB byte present.
current++;
}
if (mod == 1) { // Byte displacement.
current += 1;
} else if (mod == 2) { // 32-bit displacement.
current += 4;
} // else no immediate displacement.
AppendToBuffer("nop");
} else if (opcode == 0x28) {
AppendToBuffer("movapd %s,", NameOfXMMRegister(regop));
current += PrintRightXMMOperand(current);
} else if (opcode == 0x29) {
AppendToBuffer("movapd ");
current += PrintRightXMMOperand(current);
AppendToBuffer(",%s", NameOfXMMRegister(regop));
} else if (opcode == 0x6E) {
AppendToBuffer("mov%c %s,",
rex_w() ? 'q' : 'd',
NameOfXMMRegister(regop));
current += PrintRightOperand(current);
} else if (opcode == 0x6F) {
AppendToBuffer("movdqa %s,",
NameOfXMMRegister(regop));
current += PrintRightXMMOperand(current);
} else if (opcode == 0x7E) {
AppendToBuffer("mov%c ",
rex_w() ? 'q' : 'd');
current += PrintRightOperand(current);
AppendToBuffer(",%s", NameOfXMMRegister(regop));
} else if (opcode == 0x7F) {
AppendToBuffer("movdqa ");
current += PrintRightXMMOperand(current);
AppendToBuffer(",%s", NameOfXMMRegister(regop));
} else if (opcode == 0xD6) {
AppendToBuffer("movq ");
current += PrintRightXMMOperand(current);
AppendToBuffer(",%s", NameOfXMMRegister(regop));
} else if (opcode == 0x50) {
AppendToBuffer("movmskpd %s,", NameOfCPURegister(regop));
current += PrintRightXMMOperand(current);
} else if (opcode == 0x73) {
current += 1;
DCHECK(regop == 6);
AppendToBuffer("psllq,%s,%d", NameOfXMMRegister(rm), *current & 0x7f);
current += 1;
} else {
const char* mnemonic = "?";
if (opcode == 0x54) {
mnemonic = "andpd";
} else if (opcode == 0x56) {
mnemonic = "orpd";
} else if (opcode == 0x57) {
mnemonic = "xorpd";
} else if (opcode == 0x2E) {
mnemonic = "ucomisd";
} else if (opcode == 0x2F) {
mnemonic = "comisd";
} else {
UnimplementedInstruction();
}
AppendToBuffer("%s %s,", mnemonic, NameOfXMMRegister(regop));
current += PrintRightXMMOperand(current);
}
}
} else if (group_1_prefix_ == 0xF2) {
// Beginning of instructions with prefix 0xF2.
if (opcode == 0x11 || opcode == 0x10) {
// MOVSD: Move scalar double-precision fp to/from/between XMM registers.
AppendToBuffer("movsd ");
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
if (opcode == 0x11) {
current += PrintRightXMMOperand(current);
AppendToBuffer(",%s", NameOfXMMRegister(regop));
} else {
AppendToBuffer("%s,", NameOfXMMRegister(regop));
current += PrintRightXMMOperand(current);
}
} else if (opcode == 0x2A) {
// CVTSI2SD: integer to XMM double conversion.
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
AppendToBuffer("%sd %s,", mnemonic, NameOfXMMRegister(regop));
current += PrintRightOperand(current);
} else if (opcode == 0x2C) {
// CVTTSD2SI:
// Convert with truncation scalar double-precision FP to integer.
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
AppendToBuffer("cvttsd2si%c %s,",
operand_size_code(), NameOfCPURegister(regop));
current += PrintRightXMMOperand(current);
} else if (opcode == 0x2D) {
// CVTSD2SI: Convert scalar double-precision FP to integer.
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
AppendToBuffer("cvtsd2si%c %s,",
operand_size_code(), NameOfCPURegister(regop));
current += PrintRightXMMOperand(current);
} else if ((opcode & 0xF8) == 0x58 || opcode == 0x51) {
// XMM arithmetic. Mnemonic was retrieved at the start of this function.
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
AppendToBuffer("%s %s,", mnemonic, NameOfXMMRegister(regop));
current += PrintRightXMMOperand(current);
} else if (opcode == 0xC2) {
// Intel manual 2A, Table 3-18.
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
const char* const pseudo_op[] = {
"cmpeqsd",
"cmpltsd",
"cmplesd",
"cmpunordsd",
"cmpneqsd",
"cmpnltsd",
"cmpnlesd",
"cmpordsd"
};
AppendToBuffer("%s %s,%s",
pseudo_op[current[1]],
NameOfXMMRegister(regop),
NameOfXMMRegister(rm));
current += 2;
} else {
UnimplementedInstruction();
}
} else if (group_1_prefix_ == 0xF3) {
// Instructions with prefix 0xF3.
if (opcode == 0x11 || opcode == 0x10) {
// MOVSS: Move scalar double-precision fp to/from/between XMM registers.
AppendToBuffer("movss ");
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
if (opcode == 0x11) {
current += PrintRightOperand(current);
AppendToBuffer(",%s", NameOfXMMRegister(regop));
} else {
AppendToBuffer("%s,", NameOfXMMRegister(regop));
current += PrintRightOperand(current);
}
} else if (opcode == 0x2A) {
// CVTSI2SS: integer to XMM single conversion.
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
AppendToBuffer("%ss %s,", mnemonic, NameOfXMMRegister(regop));
current += PrintRightOperand(current);
} else if (opcode == 0x2C) {
// CVTTSS2SI:
// Convert with truncation scalar single-precision FP to dword integer.
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
AppendToBuffer("cvttss2si%c %s,",
operand_size_code(), NameOfCPURegister(regop));
current += PrintRightXMMOperand(current);
} else if (opcode == 0x5A) {
// CVTSS2SD:
// Convert scalar single-precision FP to scalar double-precision FP.
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
AppendToBuffer("cvtss2sd %s,", NameOfXMMRegister(regop));
current += PrintRightXMMOperand(current);
} else if (opcode == 0x7E) {
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
AppendToBuffer("movq %s,", NameOfXMMRegister(regop));
current += PrintRightXMMOperand(current);
} else {
UnimplementedInstruction();
}
} else if (opcode == 0x1F) {
// NOP
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
current++;
if (rm == 4) { // SIB byte present.
current++;
}
if (mod == 1) { // Byte displacement.
current += 1;
} else if (mod == 2) { // 32-bit displacement.
current += 4;
} // else no immediate displacement.
AppendToBuffer("nop");
} else if (opcode == 0x28) {
// movaps xmm, xmm/m128
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
AppendToBuffer("movaps %s,", NameOfXMMRegister(regop));
current += PrintRightXMMOperand(current);
} else if (opcode == 0x29) {
// movaps xmm/m128, xmm
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
AppendToBuffer("movaps ");
current += PrintRightXMMOperand(current);
AppendToBuffer(",%s", NameOfXMMRegister(regop));
} else if (opcode == 0xA2) {
// CPUID
AppendToBuffer("%s", mnemonic);
} else if ((opcode & 0xF0) == 0x40) {
// CMOVcc: conditional move.
int condition = opcode & 0x0F;
const InstructionDesc& idesc = cmov_instructions[condition];
byte_size_operand_ = idesc.byte_size_operation;
current += PrintOperands(idesc.mnem, idesc.op_order_, current);
} else if (opcode >= 0x53 && opcode <= 0x5F) {
const char* const pseudo_op[] = {
"rcpps",
"andps",
"andnps",
"orps",
"xorps",
"addps",
"mulps",
"cvtps2pd",
"cvtdq2ps",
"subps",
"minps",
"divps",
"maxps",
};
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
AppendToBuffer("%s %s,",
pseudo_op[opcode - 0x53],
NameOfXMMRegister(regop));
current += PrintRightXMMOperand(current);
} else if (opcode == 0xC6) {
// shufps xmm, xmm/m128, imm8
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
AppendToBuffer("shufps %s, ", NameOfXMMRegister(regop));
current += PrintRightXMMOperand(current);
AppendToBuffer(", %d", (*current) & 3);
current += 1;
} else if (opcode == 0x50) {
// movmskps reg, xmm
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
AppendToBuffer("movmskps %s,", NameOfCPURegister(regop));
current += PrintRightXMMOperand(current);
} else if ((opcode & 0xF0) == 0x80) {
// Jcc: Conditional jump (branch).
current = data + JumpConditional(data);
} else if (opcode == 0xBE || opcode == 0xBF || opcode == 0xB6 ||
opcode == 0xB7 || opcode == 0xAF) {
// Size-extending moves, IMUL.
current += PrintOperands(mnemonic, REG_OPER_OP_ORDER, current);
} else if ((opcode & 0xF0) == 0x90) {
// SETcc: Set byte on condition. Needs pointer to beginning of instruction.
current = data + SetCC(data);
} else if (opcode == 0xAB || opcode == 0xA5 || opcode == 0xAD) {
// SHLD, SHRD (double-precision shift), BTS (bit set).
AppendToBuffer("%s ", mnemonic);
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
current += PrintRightOperand(current);
if (opcode == 0xAB) {
AppendToBuffer(",%s", NameOfCPURegister(regop));
} else {
AppendToBuffer(",%s,cl", NameOfCPURegister(regop));
}
} else if (opcode == 0xBD) {
AppendToBuffer("%s%c ", mnemonic, operand_size_code());
int mod, regop, rm;
get_modrm(*current, &mod, ®op, &rm);
AppendToBuffer("%s,", NameOfCPURegister(regop));
current += PrintRightOperand(current);
} else {
UnimplementedInstruction();
}
return static_cast<int>(current - data);
}
// Mnemonics for two-byte opcode instructions starting with 0x0F.
// The argument is the second byte of the two-byte opcode.
// Returns NULL if the instruction is not handled here.
const char* DisassemblerX64::TwoByteMnemonic(byte opcode) {
switch (opcode) {
case 0x1F:
return "nop";
case 0x2A: // F2/F3 prefix.
return "cvtsi2s";
case 0x51: // F2 prefix.
return "sqrtsd";
case 0x58: // F2 prefix.
return "addsd";
case 0x59: // F2 prefix.
return "mulsd";
case 0x5A: // F2 prefix.
return "cvtsd2ss";
case 0x5C: // F2 prefix.
return "subsd";
case 0x5E: // F2 prefix.
return "divsd";
case 0xA2:
return "cpuid";
case 0xA5:
return "shld";
case 0xAB:
return "bts";
case 0xAD:
return "shrd";
case 0xAF:
return "imul";
case 0xB6:
return "movzxb";
case 0xB7:
return "movzxw";
case 0xBD:
return "bsr";
case 0xBE:
return "movsxb";
case 0xBF:
return "movsxw";
default:
return NULL;
}
}
// Disassembles the instruction at instr, and writes it into out_buffer.
int DisassemblerX64::InstructionDecode(v8::internal::Vector<char> out_buffer,
byte* instr) {
tmp_buffer_pos_ = 0; // starting to write as position 0
byte* data = instr;
bool processed = true; // Will be set to false if the current instruction
// is not in 'instructions' table.
byte current;
// Scan for prefixes.
while (true) {
current = *data;
if (current == OPERAND_SIZE_OVERRIDE_PREFIX) { // Group 3 prefix.
operand_size_ = current;
} else if ((current & 0xF0) == 0x40) { // REX prefix.
setRex(current);
if (rex_w()) AppendToBuffer("REX.W ");
} else if ((current & 0xFE) == 0xF2) { // Group 1 prefix (0xF2 or 0xF3).
group_1_prefix_ = current;
} else { // Not a prefix - an opcode.
break;
}
data++;
}
const InstructionDesc& idesc = instruction_table_->Get(current);
byte_size_operand_ = idesc.byte_size_operation;
switch (idesc.type) {
case ZERO_OPERANDS_INSTR:
if (current >= 0xA4 && current <= 0xA7) {
// String move or compare operations.
if (group_1_prefix_ == REP_PREFIX) {
// REP.
AppendToBuffer("rep ");
}
if (rex_w()) AppendToBuffer("REX.W ");
AppendToBuffer("%s%c", idesc.mnem, operand_size_code());
} else {
AppendToBuffer("%s", idesc.mnem, operand_size_code());
}
data++;
break;
case TWO_OPERANDS_INSTR:
data++;
data += PrintOperands(idesc.mnem, idesc.op_order_, data);
break;
case JUMP_CONDITIONAL_SHORT_INSTR:
data += JumpConditionalShort(data);
break;
case REGISTER_INSTR:
AppendToBuffer("%s%c %s",
idesc.mnem,
operand_size_code(),
NameOfCPURegister(base_reg(current & 0x07)));
data++;
break;
case PUSHPOP_INSTR:
AppendToBuffer("%s %s",
idesc.mnem,
NameOfCPURegister(base_reg(current & 0x07)));
data++;
break;
case MOVE_REG_INSTR: {
byte* addr = NULL;
switch (operand_size()) {
case OPERAND_WORD_SIZE:
addr = reinterpret_cast<byte*>(*reinterpret_cast<int16_t*>(data + 1));
data += 3;
break;
case OPERAND_DOUBLEWORD_SIZE:
addr =
reinterpret_cast<byte*>(*reinterpret_cast<uint32_t*>(data + 1));
data += 5;
break;
case OPERAND_QUADWORD_SIZE:
addr = reinterpret_cast<byte*>(*reinterpret_cast<int64_t*>(data + 1));
data += 9;
break;
default:
UNREACHABLE();
}
AppendToBuffer("mov%c %s,%s",
operand_size_code(),
NameOfCPURegister(base_reg(current & 0x07)),
NameOfAddress(addr));
break;
}
case CALL_JUMP_INSTR: {
byte* addr = data + *reinterpret_cast<int32_t*>(data + 1) + 5;
AppendToBuffer("%s %s", idesc.mnem, NameOfAddress(addr));
data += 5;
break;
}
case SHORT_IMMEDIATE_INSTR: {
byte* addr =
reinterpret_cast<byte*>(*reinterpret_cast<int32_t*>(data + 1));
AppendToBuffer("%s rax,%s", idesc.mnem, NameOfAddress(addr));
data += 5;
break;
}
case NO_INSTR:
processed = false;
break;
default:
UNIMPLEMENTED(); // This type is not implemented.
}
// The first byte didn't match any of the simple opcodes, so we
// need to do special processing on it.
if (!processed) {
switch (*data) {
case 0xC2:
AppendToBuffer("ret 0x%x", *reinterpret_cast<uint16_t*>(data + 1));
data += 3;
break;
case 0x69: // fall through
case 0x6B: {
int mod, regop, rm;
get_modrm(*(data + 1), &mod, ®op, &rm);
int32_t imm = *data == 0x6B ? *(data + 2)
: *reinterpret_cast<int32_t*>(data + 2);
AppendToBuffer("imul%c %s,%s,0x%x",
operand_size_code(),
NameOfCPURegister(regop),
NameOfCPURegister(rm), imm);
data += 2 + (*data == 0x6B ? 1 : 4);
break;
}
case 0x81: // fall through
case 0x83: // 0x81 with sign extension bit set
data += PrintImmediateOp(data);
break;
case 0x0F:
data += TwoByteOpcodeInstruction(data);
break;
case 0x8F: {
data++;
int mod, regop, rm;
get_modrm(*data, &mod, ®op, &rm);
if (regop == 0) {
AppendToBuffer("pop ");
data += PrintRightOperand(data);
}
}
break;
case 0xFF: {
data++;
int mod, regop, rm;
get_modrm(*data, &mod, ®op, &rm);
const char* mnem = NULL;
switch (regop) {
case 0:
mnem = "inc";
break;
case 1:
mnem = "dec";
break;
case 2:
mnem = "call";
break;
case 4:
mnem = "jmp";
break;
case 6:
mnem = "push";
break;
default:
mnem = "???";
}
AppendToBuffer(((regop <= 1) ? "%s%c " : "%s "),
mnem,
operand_size_code());
data += PrintRightOperand(data);
}
break;
case 0xC7: // imm32, fall through
case 0xC6: // imm8
{
bool is_byte = *data == 0xC6;
data++;
if (is_byte) {
AppendToBuffer("movb ");
data += PrintRightByteOperand(data);
int32_t imm = *data;
AppendToBuffer(",0x%x", imm);
data++;
} else {
AppendToBuffer("mov%c ", operand_size_code());
data += PrintRightOperand(data);
if (operand_size() == OPERAND_WORD_SIZE) {
int16_t imm = *reinterpret_cast<int16_t*>(data);
AppendToBuffer(",0x%x", imm);
data += 2;
} else {
int32_t imm = *reinterpret_cast<int32_t*>(data);
AppendToBuffer(",0x%x", imm);
data += 4;
}
}
}
break;
case 0x80: {
data++;
AppendToBuffer("cmpb ");
data += PrintRightByteOperand(data);
int32_t imm = *data;
AppendToBuffer(",0x%x", imm);
data++;
}
break;
case 0x88: // 8bit, fall through
case 0x89: // 32bit
{
bool is_byte = *data == 0x88;
int mod, regop, rm;
data++;
get_modrm(*data, &mod, ®op, &rm);
if (is_byte) {
AppendToBuffer("movb ");
data += PrintRightByteOperand(data);
AppendToBuffer(",%s", NameOfByteCPURegister(regop));
} else {
AppendToBuffer("mov%c ", operand_size_code());
data += PrintRightOperand(data);
AppendToBuffer(",%s", NameOfCPURegister(regop));
}
}
break;
case 0x90:
case 0x91:
case 0x92:
case 0x93:
case 0x94:
case 0x95:
case 0x96:
case 0x97: {
int reg = (*data & 0x7) | (rex_b() ? 8 : 0);
if (reg == 0) {
AppendToBuffer("nop"); // Common name for xchg rax,rax.
} else {
AppendToBuffer("xchg%c rax,%s",
operand_size_code(),
NameOfCPURegister(reg));
}
data++;
}
break;
case 0xB0:
case 0xB1:
case 0xB2:
case 0xB3:
case 0xB4:
case 0xB5:
case 0xB6:
case 0xB7:
case 0xB8:
case 0xB9:
case 0xBA:
case 0xBB:
case 0xBC:
case 0xBD:
case 0xBE:
case 0xBF: {
// mov reg8,imm8 or mov reg32,imm32
byte opcode = *data;
data++;
bool is_32bit = (opcode >= 0xB8);
int reg = (opcode & 0x7) | (rex_b() ? 8 : 0);
if (is_32bit) {
AppendToBuffer("mov%c %s,",
operand_size_code(),
NameOfCPURegister(reg));
data += PrintImmediate(data, OPERAND_DOUBLEWORD_SIZE);
} else {
AppendToBuffer("movb %s,",
NameOfByteCPURegister(reg));
data += PrintImmediate(data, OPERAND_BYTE_SIZE);
}
break;
}
case 0xFE: {
data++;
int mod, regop, rm;
get_modrm(*data, &mod, ®op, &rm);
if (regop == 1) {
AppendToBuffer("decb ");
data += PrintRightByteOperand(data);
} else {
UnimplementedInstruction();
}
break;
}
case 0x68:
AppendToBuffer("push 0x%x", *reinterpret_cast<int32_t*>(data + 1));
data += 5;
break;
case 0x6A:
AppendToBuffer("push 0x%x", *reinterpret_cast<int8_t*>(data + 1));
data += 2;
break;
case 0xA1: // Fall through.
case 0xA3:
switch (operand_size()) {
case OPERAND_DOUBLEWORD_SIZE: {
const char* memory_location = NameOfAddress(
reinterpret_cast<byte*>(
*reinterpret_cast<int32_t*>(data + 1)));
if (*data == 0xA1) { // Opcode 0xA1
AppendToBuffer("movzxlq rax,(%s)", memory_location);
} else { // Opcode 0xA3
AppendToBuffer("movzxlq (%s),rax", memory_location);
}
data += 5;
break;
}
case OPERAND_QUADWORD_SIZE: {
// New x64 instruction mov rax,(imm_64).
const char* memory_location = NameOfAddress(
*reinterpret_cast<byte**>(data + 1));
if (*data == 0xA1) { // Opcode 0xA1
AppendToBuffer("movq rax,(%s)", memory_location);
} else { // Opcode 0xA3
AppendToBuffer("movq (%s),rax", memory_location);
}
data += 9;
break;
}
default:
UnimplementedInstruction();
data += 2;
}
break;
case 0xA8:
AppendToBuffer("test al,0x%x", *reinterpret_cast<uint8_t*>(data + 1));
data += 2;
break;
case 0xA9: {
int64_t value = 0;
switch (operand_size()) {
case OPERAND_WORD_SIZE:
value = *reinterpret_cast<uint16_t*>(data + 1);
data += 3;
break;
case OPERAND_DOUBLEWORD_SIZE:
value = *reinterpret_cast<uint32_t*>(data + 1);
data += 5;
break;
case OPERAND_QUADWORD_SIZE:
value = *reinterpret_cast<int32_t*>(data + 1);
data += 5;
break;
default:
UNREACHABLE();
}
AppendToBuffer("test%c rax,0x%" V8_PTR_PREFIX "x",
operand_size_code(),
value);
break;
}
case 0xD1: // fall through
case 0xD3: // fall through
case 0xC1:
data += ShiftInstruction(data);
break;
case 0xD0: // fall through
case 0xD2: // fall through
case 0xC0:
byte_size_operand_ = true;
data += ShiftInstruction(data);
break;
case 0xD9: // fall through
case 0xDA: // fall through
case 0xDB: // fall through
case 0xDC: // fall through
case 0xDD: // fall through
case 0xDE: // fall through
case 0xDF:
data += FPUInstruction(data);
break;
case 0xEB:
data += JumpShort(data);
break;
case 0xF6:
byte_size_operand_ = true; // fall through
case 0xF7:
data += F6F7Instruction(data);
break;
case 0x3C:
AppendToBuffer("cmp al,0x%x", *reinterpret_cast<int8_t*>(data + 1));
data +=2;
break;
default:
UnimplementedInstruction();
data += 1;
}
} // !processed
if (tmp_buffer_pos_ < sizeof tmp_buffer_) {
tmp_buffer_[tmp_buffer_pos_] = '\0';
}
int instr_len = static_cast<int>(data - instr);
DCHECK(instr_len > 0); // Ensure progress.
int outp = 0;
// Instruction bytes.
for (byte* bp = instr; bp < data; bp++) {
outp += v8::internal::SNPrintF(out_buffer + outp, "%02x", *bp);
}
for (int i = 6 - instr_len; i >= 0; i--) {
outp += v8::internal::SNPrintF(out_buffer + outp, " ");
}
outp += v8::internal::SNPrintF(out_buffer + outp, " %s",
tmp_buffer_.start());
return instr_len;
}
//------------------------------------------------------------------------------
static const char* cpu_regs[16] = {
"rax", "rcx", "rdx", "rbx", "rsp", "rbp", "rsi", "rdi",
"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15"
};
static const char* byte_cpu_regs[16] = {
"al", "cl", "dl", "bl", "spl", "bpl", "sil", "dil",
"r8l", "r9l", "r10l", "r11l", "r12l", "r13l", "r14l", "r15l"
};
static const char* xmm_regs[16] = {
"xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5", "xmm6", "xmm7",
"xmm8", "xmm9", "xmm10", "xmm11", "xmm12", "xmm13", "xmm14", "xmm15"
};
const char* NameConverter::NameOfAddress(byte* addr) const {
v8::internal::SNPrintF(tmp_buffer_, "%p", addr);
return tmp_buffer_.start();
}
const char* NameConverter::NameOfConstant(byte* addr) const {
return NameOfAddress(addr);
}
const char* NameConverter::NameOfCPURegister(int reg) const {
if (0 <= reg && reg < 16)
return cpu_regs[reg];
return "noreg";
}
const char* NameConverter::NameOfByteCPURegister(int reg) const {
if (0 <= reg && reg < 16)
return byte_cpu_regs[reg];
return "noreg";
}
const char* NameConverter::NameOfXMMRegister(int reg) const {
if (0 <= reg && reg < 16)
return xmm_regs[reg];
return "noxmmreg";
}
const char* NameConverter::NameInCode(byte* addr) const {
// X64 does not embed debug strings at the moment.
UNREACHABLE();
return "";
}
//------------------------------------------------------------------------------
Disassembler::Disassembler(const NameConverter& converter)
: converter_(converter) { }
Disassembler::~Disassembler() { }
int Disassembler::InstructionDecode(v8::internal::Vector<char> buffer,
byte* instruction) {
DisassemblerX64 d(converter_, CONTINUE_ON_UNIMPLEMENTED_OPCODE);
return d.InstructionDecode(buffer, instruction);
}
// The X64 assembler does not use constant pools.
int Disassembler::ConstantPoolSizeAt(byte* instruction) {
return -1;
}
void Disassembler::Disassemble(FILE* f, byte* begin, byte* end) {
NameConverter converter;
Disassembler d(converter);
for (byte* pc = begin; pc < end;) {
v8::internal::EmbeddedVector<char, 128> buffer;
buffer[0] = '\0';
byte* prev_pc = pc;
pc += d.InstructionDecode(buffer, pc);
fprintf(f, "%p", prev_pc);
fprintf(f, " ");
for (byte* bp = prev_pc; bp < pc; bp++) {
fprintf(f, "%02x", *bp);
}
for (int i = 6 - static_cast<int>(pc - prev_pc); i >= 0; i--) {
fprintf(f, " ");
}
fprintf(f, " %s\n", buffer.start());
}
}
} // namespace disasm
#endif // V8_TARGET_ARCH_X64