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// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/disassembler.h"
#include "vm/globals.h" // Needed here to get TARGET_ARCH_IA32.
#if defined(TARGET_ARCH_X64)
#include "platform/utils.h"
#include "vm/allocation.h"
#include "vm/heap.h"
#include "vm/os.h"
#include "vm/stack_frame.h"
#include "vm/stub_code.h"
namespace dart {
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, "movsxlq" },
{ 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 ValueObject {
public:
InstructionTable();
const InstructionDesc& Get(uint8_t x) const {
return instructions_[x];
}
private:
InstructionDesc instructions_[256];
void Clear();
void Init();
void CopyTable(const ByteMnemonic bm[], InstructionType type);
void SetTableRange(InstructionType type,
uint8_t start,
uint8_t end,
bool byte_size,
const char* mnem);
void AddJumpConditionalShort();
DISALLOW_COPY_AND_ASSIGN(InstructionTable);
};
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);
ASSERT(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,
uint8_t start,
uint8_t end,
bool byte_size,
const char* mnem) {
for (uint8_t b = start; b <= end; b++) {
InstructionDesc* id = &instructions_[b];
ASSERT(NO_INSTR == id->type); // Information not already entered
id->mnem = mnem;
id->type = type;
id->byte_size_operation = byte_size;
}
}
void InstructionTable::AddJumpConditionalShort() {
for (uint8_t b = 0x70; b <= 0x7F; b++) {
InstructionDesc* id = &instructions_[b];
ASSERT(NO_INSTR == id->type); // Information not already entered
id->mnem = NULL; // Computed depending on condition code.
id->type = JUMP_CONDITIONAL_SHORT_INSTR;
}
}
static InstructionTable instruction_table;
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.
static const int kMaxXmmRegisters = 16;
static const char* xmm_regs[kMaxXmmRegisters] = {
"xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5", "xmm6", "xmm7",
"xmm8", "xmm9", "xmm10", "xmm11", "xmm12", "xmm13", "xmm14", "xmm15"
};
class DisassemblerX64 : public ValueObject {
public:
DisassemblerX64(char* buffer, intptr_t buffer_size)
: buffer_(buffer),
buffer_size_(buffer_size),
buffer_pos_(0),
rex_(0),
operand_size_(0),
group_1_prefix_(0),
byte_size_operand_(false) {
buffer_[buffer_pos_] = '\0';
}
virtual ~DisassemblerX64() {
}
int InstructionDecode(uword pc);
private:
enum OperandSize {
BYTE_SIZE = 0,
WORD_SIZE = 1,
DOUBLEWORD_SIZE = 2,
QUADWORD_SIZE = 3
};
void setRex(uint8_t rex) {
ASSERT(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 BYTE_SIZE;
if (rex_w()) return QUADWORD_SIZE;
if (operand_size_ != 0) return WORD_SIZE;
return DOUBLEWORD_SIZE;
}
char operand_size_code() {
return "bwlq"[operand_size()];
}
// Disassembler helper functions.
void get_modrm(uint8_t 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(uint8_t 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);
}
const char* NameOfCPURegister(int reg) const {
return Assembler::RegisterName(static_cast<Register>(reg));
}
const char* NameOfByteCPURegister(int reg) const {
return NameOfCPURegister(reg);
}
const char* NameOfXMMRegister(int reg) const {
ASSERT((0 <= reg) && (reg < kMaxXmmRegisters));
return xmm_regs[reg];
}
void AppendToBuffer(const char* format, ...) PRINTF_ATTRIBUTE(2, 3);
void AppendAddressToBuffer(uint8_t* addr);
int PrintOperands(const char* mnem,
OperandType op_order,
uint8_t* data);
typedef const char* (DisassemblerX64::*RegisterNameMapping)(int reg) const;
int PrintRightOperandHelper(uint8_t* modrmp,
RegisterNameMapping register_name);
int PrintRightOperand(uint8_t* modrmp);
int PrintRightByteOperand(uint8_t* modrmp);
int PrintRightXMMOperand(uint8_t* modrmp);
int PrintImmediate(uint8_t* data, OperandSize size);
int PrintImmediateOp(uint8_t* data);
const char* TwoByteMnemonic(uint8_t opcode);
int TwoByteOpcodeInstruction(uint8_t* data);
int F6F7Instruction(uint8_t* data);
int ShiftInstruction(uint8_t* data);
int JumpShort(uint8_t* data);
int JumpConditional(uint8_t* data);
int JumpConditionalShort(uint8_t* data);
int SetCC(uint8_t* data);
int FPUInstruction(uint8_t* data);
int MemoryFPUInstruction(int escape_opcode, int regop, uint8_t* modrm_start);
int RegisterFPUInstruction(int escape_opcode, uint8_t modrm_byte);
bool DecodeInstructionType(uint8_t** data);
void UnimplementedInstruction() {
AppendToBuffer("'Unimplemented Instruction'");
}
char* buffer_; // Decode instructions into this buffer.
intptr_t buffer_size_; // The size of the buffer_.
intptr_t buffer_pos_; // Current character position in the buffer_.
// Prefixes parsed
uint8_t rex_;
uint8_t operand_size_; // 0x66 or (if no group 3 prefix is present) 0x0.
// 0xF2, 0xF3, or (if no group 1 prefix is present) 0.
uint8_t group_1_prefix_;
// Byte size operand override.
bool byte_size_operand_;
DISALLOW_COPY_AND_ASSIGN(DisassemblerX64);
};
// Append the str to the output buffer.
void DisassemblerX64::AppendToBuffer(const char* format, ...) {
intptr_t available = buffer_size_ - buffer_pos_;
if (available <= 1) {
ASSERT(buffer_[buffer_pos_] == '\0');
return;
}
char* buf = buffer_ + buffer_pos_;
va_list args;
va_start(args, format);
int length = OS::VSNPrint(buf, available, format, args);
va_end(args);
buffer_pos_ =
(length >= available) ? (buffer_size_ - 1) : (buffer_pos_ + length);
ASSERT(buffer_pos_ < buffer_size_);
}
int DisassemblerX64::PrintRightOperandHelper(
uint8_t* modrmp,
RegisterNameMapping direct_register_name) {
int mod, regop, rm;
get_modrm(*modrmp, &mod, &regop, &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("[%#x]", disp);
return 5;
} else if ((rm & 7) == 4) {
// Codes for SIB byte.
uint8_t 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+%#x]",
NameOfCPURegister(index),
1 << scale, 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) {
uint8_t 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<char*>(modrmp + 2);
if (index == 4 && (base & 7) == 4 && scale == 0 /*times_1*/) {
if (-disp > 0) {
AppendToBuffer("[%s-%#x]", NameOfCPURegister(base), -disp);
} else {
AppendToBuffer("[%s+%#x]", NameOfCPURegister(base), disp);
}
} else {
if (-disp > 0) {
AppendToBuffer("[%s+%s*%d-%#x]",
NameOfCPURegister(base),
NameOfCPURegister(index),
1 << scale,
-disp);
} else {
AppendToBuffer("[%s+%s*%d+%#x]",
NameOfCPURegister(base),
NameOfCPURegister(index),
1 << scale,
disp);
}
}
return mod == 2 ? 6 : 3;
} else {
// No sib.
int disp = (mod == 2) ? *reinterpret_cast<int32_t*>(modrmp + 1)
: *reinterpret_cast<char*>(modrmp + 1);
if (-disp > 0) {
AppendToBuffer("[%s-%#x]", NameOfCPURegister(rm), -disp);
} else {
AppendToBuffer("[%s+%#x]", NameOfCPURegister(rm), 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(uint8_t* data, OperandSize size) {
int64_t value;
int count;
switch (size) {
case BYTE_SIZE:
value = *data;
count = 1;
break;
case WORD_SIZE:
value = *reinterpret_cast<int16_t*>(data);
count = 2;
break;
case DOUBLEWORD_SIZE:
value = *reinterpret_cast<uint32_t*>(data);
count = 4;
break;
case 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("%#"Px64"", value);
return count;
}
// Returns number of bytes used by machine instruction, including *data byte.
// Writes immediate instructions to 'tmp_buffer_'.
int DisassemblerX64::PrintImmediateOp(uint8_t* data) {
bool byte_size_immediate = (*data & 0x02) != 0;
uint8_t modrm = *(data + 1);
int mod, regop, rm;
get_modrm(modrm, &mod, &regop, &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 ? BYTE_SIZE : operand_size();
count += PrintImmediate(data + 1 + count, immediate_size);
return 1 + count;
}
// Returns number of bytes used, including *data.
int DisassemblerX64::F6F7Instruction(uint8_t* data) {
ASSERT(*data == 0xF7 || *data == 0xF6);
uint8_t modrm = *(data + 1);
int mod, regop, rm;
get_modrm(modrm, &mod, &regop, &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 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(uint8_t* data) {
uint8_t op = *data & (~1);
if (op != 0xD0 && op != 0xD2 && op != 0xC0) {
UnimplementedInstruction();
return 1;
}
uint8_t modrm = *(data + 1);
int mod, regop, rm;
get_modrm(modrm, &mod, &regop, &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;
}
ASSERT(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;
}
int DisassemblerX64::PrintRightOperand(uint8_t* modrmp) {
return PrintRightOperandHelper(modrmp,
&DisassemblerX64::NameOfCPURegister);
}
int DisassemblerX64::PrintRightByteOperand(uint8_t* modrmp) {
return PrintRightOperandHelper(modrmp,
&DisassemblerX64::NameOfByteCPURegister);
}
int DisassemblerX64::PrintRightXMMOperand(uint8_t* 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,
uint8_t* data) {
uint8_t modrm = *data;
int mod, regop, rm;
get_modrm(modrm, &mod, &regop, &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;
}
static const char* ObjectToCStringNoGC(const Object& obj) {
if (obj.IsSmi() ||
obj.IsMint() ||
obj.IsDouble() ||
obj.IsString() ||
obj.IsNull() ||
obj.IsBool() ||
obj.IsClass() ||
obj.IsFunction() ||
obj.IsICData() ||
obj.IsField()) {
return obj.ToCString();
}
const Class& clazz = Class::CheckedHandle(obj.clazz());
const char* full_class_name = clazz.ToCString();
const char* format = "instance of %s";
intptr_t len = OS::SNPrint(NULL, 0, format, full_class_name) + 1;
char* chars = Isolate::Current()->current_zone()->Alloc<char>(len);
OS::SNPrint(chars, len, format, full_class_name);
return chars;
}
void DisassemblerX64::AppendAddressToBuffer(uint8_t* addr_byte_ptr) {
NoGCScope no_gc;
uword addr = reinterpret_cast<uword>(addr_byte_ptr);
AppendToBuffer("%#"Px"", addr);
// Try to print as heap object or stub name
if (((addr & kSmiTagMask) == kHeapObjectTag) &&
!Isolate::Current()->heap()->CodeContains(addr) &&
Isolate::Current()->heap()->Contains(addr - kHeapObjectTag)) {
Object& obj = Object::Handle(reinterpret_cast<RawObject*>(addr));
if (obj.IsArray()) {
const Array& arr = Array::CheckedHandle(obj.raw());
intptr_t len = arr.Length();
if (len > 5) len = 5; // Print a max of 5 elements.
AppendToBuffer(" Array[");
int i = 0;
while (i < len) {
obj = arr.At(i);
if (i > 0) AppendToBuffer(", ");
AppendToBuffer("%s", ObjectToCStringNoGC(obj));
i++;
}
if (i < arr.Length()) AppendToBuffer(", ...");
AppendToBuffer("]");
return;
}
AppendToBuffer(" '%s'", ObjectToCStringNoGC(obj));
} else {
// 'addr' is not an object, but probably a code address.
const char* name_of_stub = StubCode::NameOfStub(addr);
if (name_of_stub != NULL) {
AppendToBuffer(" [stub: %s]", name_of_stub);
} else {
// Print only if jumping to entry point.
const Code& code = Code::Handle(Code::LookupCode(addr));
if (!code.IsNull() && (code.EntryPoint() == addr)) {
const Function& function = Function::Handle(code.function());
if (function.IsNull()) {
AppendToBuffer(" [ stub ]");
} else {
const char* name_of_function = function.ToFullyQualifiedCString();
AppendToBuffer(" [%s]", name_of_function);
}
}
}
}
}
// Returns number of bytes used, including *data.
int DisassemblerX64::JumpShort(uint8_t* data) {
ASSERT(0xEB == *data);
uint8_t b = *(data + 1);
uint8_t* dest = data + static_cast<int8_t>(b) + 2;
AppendToBuffer("jmp ");
AppendAddressToBuffer(dest);
return 2;
}
// Returns number of bytes used, including *data.
int DisassemblerX64::JumpConditional(uint8_t* data) {
ASSERT(0x0F == *data);
uint8_t cond = *(data + 1) & 0x0F;
uint8_t* dest = data + *reinterpret_cast<int32_t*>(data + 2) + 6;
const char* mnem = conditional_code_suffix[cond];
AppendToBuffer("j%s ", mnem);
AppendAddressToBuffer(dest);
return 6; // includes 0x0F
}
// Returns number of bytes used, including *data.
int DisassemblerX64::JumpConditionalShort(uint8_t* data) {
uint8_t cond = *data & 0x0F;
uint8_t b = *(data + 1);
uint8_t* dest = data + static_cast<uint8_t>(b) + 2;
const char* mnem = conditional_code_suffix[cond];
AppendToBuffer("j%s ", mnem);
AppendAddressToBuffer(dest);
return 2;
}
// Returns number of bytes used, including *data.
int DisassemblerX64::SetCC(uint8_t* data) {
ASSERT(0x0F == *data);
uint8_t 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(uint8_t* data) {
uint8_t escape_opcode = *data;
ASSERT(0xD8 == (escape_opcode & 0xF8));
uint8_t 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,
uint8_t* 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,
uint8_t 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 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 {
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;
}
// TODO(srdjan): Should we add a branch hint argument?
bool DisassemblerX64::DecodeInstructionType(uint8_t** data) {
uint8_t 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);
// TODO(srdjan): Should we enable printing of REX.W?
// 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 ");
}
// TODO(srdjan): Should we enable printing of REX.W?
// if (rex_w()) AppendToBuffer("REX.W ");
AppendToBuffer("%s%c", idesc.mnem, operand_size_code());
} else {
AppendToBuffer("%s%c", 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: {
uint8_t* addr = NULL;
switch (operand_size()) {
case WORD_SIZE:
addr = reinterpret_cast<uint8_t*>(
*reinterpret_cast<int16_t*>(*data + 1));
(*data) += 3;
break;
case DOUBLEWORD_SIZE:
addr = reinterpret_cast<uint8_t*>(
*reinterpret_cast<int32_t*>(*data + 1));
(*data) += 5;
break;
case QUADWORD_SIZE:
addr = reinterpret_cast<uint8_t*>(
*reinterpret_cast<int64_t*>(*data + 1));
(*data) += 9;
break;
default:
UNREACHABLE();
}
AppendToBuffer("mov%c %s,",
operand_size_code(),
NameOfCPURegister(base_reg(current & 0x07)));
AppendAddressToBuffer(addr);
break;
}
case CALL_JUMP_INSTR: {
uint8_t* addr = *data + *reinterpret_cast<int32_t*>(*data + 1) + 5;
AppendToBuffer("%s ", idesc.mnem);
AppendAddressToBuffer(addr);
(*data) += 5;
break;
}
case SHORT_IMMEDIATE_INSTR: {
uint8_t* addr =
reinterpret_cast<uint8_t*>(*reinterpret_cast<int32_t*>(*data + 1));
AppendToBuffer("%s rax, ", idesc.mnem);
AppendAddressToBuffer(addr);
(*data) += 5;
break;
}
case NO_INSTR:
return false;
default:
UNIMPLEMENTED(); // This type is not implemented.
}
return true;
}
// 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(uint8_t* data) {
uint8_t opcode = *(data + 1);
uint8_t* 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) {
uint8_t third_byte = *current;
current = data + 3;
if (third_byte == 0x17) {
get_modrm(*current, &mod, &regop, &rm);
AppendToBuffer("extractps "); // reg/m32, xmm, imm8
current += PrintRightOperand(current);
AppendToBuffer(", %s, %d", NameOfCPURegister(regop), (*current) & 3);
current += 1;
} else if (third_byte == 0x0b) {
get_modrm(*current, &mod, &regop, &rm);
// roundsd xmm, xmm/m64, imm8
AppendToBuffer("roundsd %s, ", NameOfCPURegister(regop));
current += PrintRightOperand(current);
AppendToBuffer(", %d", (*current) & 3);
current += 1;
} else {
UnimplementedInstruction();
}
} else {
get_modrm(*current, &mod, &regop, &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 {
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, &regop, &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, &regop, &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, &regop, &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, &regop, &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, &regop, &rm);
AppendToBuffer("%s %s,", mnemonic, NameOfXMMRegister(regop));
current += PrintRightXMMOperand(current);
} 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, &regop, &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, &regop, &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, &regop, &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, &regop, &rm);
AppendToBuffer("cvtss2sd %s,", NameOfXMMRegister(regop));
current += PrintRightXMMOperand(current);
} else if (opcode == 0x7E) {
int mod, regop, rm;
get_modrm(*current, &mod, &regop, &rm);
AppendToBuffer("movq %s, ", NameOfXMMRegister(regop));
current += PrintRightXMMOperand(current);
} else {
UnimplementedInstruction();
}
} else if (opcode == 0x1F) {
// NOP
int mod, regop, rm;
get_modrm(*current, &mod, &regop, &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, &regop, &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, &regop, &rm);
AppendToBuffer("movaps ");
current += PrintRightXMMOperand(current);
AppendToBuffer(", %s", NameOfXMMRegister(regop));
} else if (opcode == 0xA2 || opcode == 0x31) {
// RDTSC or 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 == 0x57) {
// xorps xmm, xmm/m128
int mod, regop, rm;
get_modrm(*current, &mod, &regop, &rm);
AppendToBuffer("xorps %s, ", NameOfXMMRegister(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, &regop, &rm);
current += PrintRightOperand(current);
if (opcode == 0xAB) {
AppendToBuffer(",%s", NameOfCPURegister(regop));
} else {
AppendToBuffer(",%s,cl", NameOfCPURegister(regop));
}
} 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(uint8_t opcode) {
switch (opcode) {
case 0x1F:
return "nop";
case 0x2A: // F2/F3 prefix.
return "cvtsi2s";
case 0x31:
return "rdtsc";
case 0x51: // F2 prefix.
return "sqrtsd";
case 0x58: // F2 prefix.
return "addsd";
case 0x59: // F2 prefix.
return "mulsd";
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 0xBE:
return "movsxb";
case 0xBF:
return "movsxw";
default:
return NULL;
}
}
int DisassemblerX64::InstructionDecode(uword pc) {
uint8_t* data = reinterpret_cast<uint8_t*>(pc);
const bool processed = DecodeInstructionType(&data);
if (!processed) {
switch (*data) {
case 0xC2:
AppendToBuffer("ret %#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, &regop, &rm);
int32_t imm = *data == 0x6B ? *(data + 2)
: *reinterpret_cast<int32_t*>(data + 2);
AppendToBuffer("imul%c %s,%s,%#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, &regop, &rm);
if (regop == 0) {
AppendToBuffer("pop ");
data += PrintRightOperand(data);
}
}
break;
case 0xFF: {
data++;
int mod, regop, rm;
get_modrm(*data, &mod, &regop, &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 = "???";
}
if (regop <= 1) {
AppendToBuffer("%s%c ", mnem, operand_size_code());
} else {
AppendToBuffer("%s ", mnem);
}
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(",%#x", imm);
data++;
} else {
AppendToBuffer("mov%c ", operand_size_code());
data += PrintRightOperand(data);
int32_t imm = *reinterpret_cast<int32_t*>(data);
AppendToBuffer(",%#x", imm);
data += 4;
}
}
break;
case 0x80: {
data++;
AppendToBuffer("cmpb ");
data += PrintRightByteOperand(data);
int32_t imm = *data;
AppendToBuffer(",%#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, &regop, &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
uint8_t opcode = *data;
data++;
uint8_t 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, DOUBLEWORD_SIZE);
} else {
AppendToBuffer("movb %s, ",
NameOfByteCPURegister(reg));
data += PrintImmediate(data, BYTE_SIZE);
}
break;
}
case 0xFE: {
data++;
int mod, regop, rm;
get_modrm(*data, &mod, &regop, &rm);
if (regop == 1) {
AppendToBuffer("decb ");
data += PrintRightByteOperand(data);
} else {
UnimplementedInstruction();
}
break;
}
case 0x68:
AppendToBuffer("push %#x", *reinterpret_cast<int32_t*>(data + 1));
data += 5;
break;
case 0x6A:
AppendToBuffer("push %#x", *reinterpret_cast<int8_t*>(data + 1));
data += 2;
break;
case 0xA1: // Fall through.
case 0xA3:
switch (operand_size()) {
case DOUBLEWORD_SIZE: {
AppendAddressToBuffer(
reinterpret_cast<uint8_t*>(
*reinterpret_cast<int32_t*>(data + 1)));
if (*data == 0xA1) { // Opcode 0xA1
AppendToBuffer("movzxlq rax,(");
AppendAddressToBuffer(
reinterpret_cast<uint8_t*>(
*reinterpret_cast<int32_t*>(data + 1)));
AppendToBuffer(")");
} else { // Opcode 0xA3
AppendToBuffer("movzxlq (");
AppendAddressToBuffer(
reinterpret_cast<uint8_t*>(
*reinterpret_cast<int32_t*>(data + 1)));
AppendToBuffer("),rax");
}
data += 5;
break;
}
case QUADWORD_SIZE: {
// New x64 instruction mov rax,(imm_64).
if (*data == 0xA1) { // Opcode 0xA1
AppendToBuffer("movq rax,(");
AppendAddressToBuffer(*reinterpret_cast<uint8_t**>(data + 1));
AppendToBuffer(")");
} else { // Opcode 0xA3
AppendToBuffer("movq (");
AppendAddressToBuffer(*reinterpret_cast<uint8_t**>(data + 1));
AppendToBuffer("),rax");
}
data += 9;
break;
}
default:
UnimplementedInstruction();
data += 2;
}
break;
case 0xA8:
AppendToBuffer("test al,%#x", *reinterpret_cast<uint8_t*>(data + 1));
data += 2;
break;
case 0xA9: {
int64_t value = 0;
switch (operand_size()) {
case WORD_SIZE:
value = *reinterpret_cast<uint16_t*>(data + 1);
data += 3;
break;
case DOUBLEWORD_SIZE:
value = *reinterpret_cast<uint32_t*>(data + 1);
data += 5;
break;
case QUADWORD_SIZE:
value = *reinterpret_cast<int32_t*>(data + 1);
data += 5;
break;
default:
UNREACHABLE();
}
AppendToBuffer("test%c rax,%#"Px64"",
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;
default:
UnimplementedInstruction();
data += 1;
}
} // !processed
ASSERT(buffer_[buffer_pos_] == '\0');
int instr_len = data - reinterpret_cast<uint8_t*>(pc);
ASSERT(instr_len > 0); // Ensure progress.
return instr_len;
}
int Disassembler::DecodeInstruction(char* hex_buffer, intptr_t hex_size,
char* human_buffer, intptr_t human_size,
uword pc) {
ASSERT(hex_size > 0);
ASSERT(human_size > 0);
DisassemblerX64 decoder(human_buffer, human_size);
int instruction_length = decoder.InstructionDecode(pc);
uint8_t* pc_ptr = reinterpret_cast<uint8_t*>(pc);
int hex_index = 0;
int remaining_size = hex_size - hex_index;
for (int i = 0; (i < instruction_length) && (remaining_size > 2); ++i) {
OS::SNPrint(&hex_buffer[hex_index], remaining_size, "%02x", pc_ptr[i]);
hex_index += 2;
remaining_size -= 2;
}
hex_buffer[hex_index] = '\0';
return instruction_length;
}
void Disassembler::Disassemble(uword start,
uword end,
DisassemblyFormatter* formatter,
const Code::Comments& comments) {
ASSERT(formatter != NULL);
char hex_buffer[kHexadecimalBufferSize]; // Instruction in hexadecimal form.
char human_buffer[kUserReadableBufferSize]; // Human-readable instruction.
uword pc = start;
intptr_t comment_finger = 0;
while (pc < end) {
const intptr_t offset = pc - start;
while (comment_finger < comments.Length() &&
comments.PCOffsetAt(comment_finger) <= offset) {
formatter->Print(" ;; %s\n",
comments.CommentAt(comment_finger).ToCString());
comment_finger++;
}
int instruction_length = DecodeInstruction(hex_buffer,
sizeof(hex_buffer),
human_buffer,
sizeof(human_buffer),
pc);
formatter->ConsumeInstruction(hex_buffer,
sizeof(hex_buffer),
human_buffer,
sizeof(human_buffer),
pc);
pc += instruction_length;
}
}
} // namespace dart
#endif // defined TARGET_ARCH_X64