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v8/src/disasm-ia32.cc
bak@chromium.org eb816ae54a Fixed the disassembler to cope with cmpb. 
Review URL: http://codereview.chromium.org/40296

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1455 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2009-03-09 14:41:40 +00:00

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// Copyright 2007-2008 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include <assert.h>
#include <stdio.h>
#include <stdarg.h>
#include "v8.h"
#include "disasm.h"
namespace disasm {
enum OperandOrder {
UNSET_OP_ORDER = 0,
REG_OPER_OP_ORDER,
OPER_REG_OP_ORDER
};
//------------------------------------------------------------------
// Tables
//------------------------------------------------------------------
struct ByteMnemonic {
int b; // -1 terminates, otherwise must be in range (0..255)
const char* mnem;
OperandOrder op_order_;
};
static ByteMnemonic two_operands_instr[] = {
{0x03, "add", REG_OPER_OP_ORDER},
{0x21, "and", OPER_REG_OP_ORDER},
{0x23, "and", REG_OPER_OP_ORDER},
{0x3B, "cmp", REG_OPER_OP_ORDER},
{0x8D, "lea", REG_OPER_OP_ORDER},
{0x09, "or", OPER_REG_OP_ORDER},
{0x0B, "or", REG_OPER_OP_ORDER},
{0x1B, "sbb", REG_OPER_OP_ORDER},
{0x29, "sub", OPER_REG_OP_ORDER},
{0x2B, "sub", REG_OPER_OP_ORDER},
{0x85, "test", REG_OPER_OP_ORDER},
{0x31, "xor", OPER_REG_OP_ORDER},
{0x33, "xor", REG_OPER_OP_ORDER},
{0x87, "xchg", REG_OPER_OP_ORDER},
{0x8A, "mov_b", REG_OPER_OP_ORDER},
{0x8B, "mov", REG_OPER_OP_ORDER},
{-1, "", UNSET_OP_ORDER}
};
static ByteMnemonic zero_operands_instr[] = {
{0xC3, "ret", UNSET_OP_ORDER},
{0xC9, "leave", UNSET_OP_ORDER},
{0x90, "nop", UNSET_OP_ORDER},
{0xF4, "hlt", UNSET_OP_ORDER},
{0xCC, "int3", UNSET_OP_ORDER},
{0x60, "pushad", UNSET_OP_ORDER},
{0x61, "popad", UNSET_OP_ORDER},
{0x9C, "pushfd", UNSET_OP_ORDER},
{0x9D, "popfd", UNSET_OP_ORDER},
{0x9E, "sahf", UNSET_OP_ORDER},
{0x99, "cdq", UNSET_OP_ORDER},
{0x9B, "fwait", UNSET_OP_ORDER},
{-1, "", UNSET_OP_ORDER}
};
static ByteMnemonic call_jump_instr[] = {
{0xE8, "call", UNSET_OP_ORDER},
{0xE9, "jmp", UNSET_OP_ORDER},
{-1, "", UNSET_OP_ORDER}
};
static ByteMnemonic short_immediate_instr[] = {
{0x05, "add", UNSET_OP_ORDER},
{0x0D, "or", UNSET_OP_ORDER},
{0x15, "adc", UNSET_OP_ORDER},
{0x25, "and", UNSET_OP_ORDER},
{0x2D, "sub", UNSET_OP_ORDER},
{0x35, "xor", UNSET_OP_ORDER},
{0x3D, "cmp", UNSET_OP_ORDER},
{-1, "", UNSET_OP_ORDER}
};
static const char* jump_conditional_mnem[] = {
/*0*/ "jo", "jno", "jc", "jnc",
/*4*/ "jz", "jnz", "jna", "ja",
/*8*/ "js", "jns", "jpe", "jpo",
/*12*/ "jl", "jnl", "jng", "jg"
};
static const char* set_conditional_mnem[] = {
/*0*/ "seto", "setno", "setc", "setnc",
/*4*/ "setz", "setnz", "setna", "seta",
/*8*/ "sets", "setns", "setpe", "setpo",
/*12*/ "setl", "setnl", "setng", "setg"
};
enum InstructionType {
NO_INSTR,
ZERO_OPERANDS_INSTR,
TWO_OPERANDS_INSTR,
JUMP_CONDITIONAL_SHORT_INSTR,
REGISTER_INSTR,
MOVE_REG_INSTR,
CALL_JUMP_INSTR,
SHORT_IMMEDIATE_INSTR
};
struct InstructionDesc {
const char* mnem;
InstructionType type;
OperandOrder op_order_;
};
class InstructionTable {
public:
InstructionTable();
const InstructionDesc& Get(byte x) const { return instructions_[x]; }
private:
InstructionDesc instructions_[256];
void Clear();
void Init();
void CopyTable(ByteMnemonic bm[], InstructionType type);
void SetTableRange(InstructionType type,
byte start,
byte end,
const char* mnem);
void AddJumpConditionalShort();
};
InstructionTable::InstructionTable() {
Clear();
Init();
}
void InstructionTable::Clear() {
for (int i = 0; i < 256; i++) {
instructions_[i].mnem = "";
instructions_[i].type = NO_INSTR;
instructions_[i].op_order_ = UNSET_OP_ORDER;
}
}
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(REGISTER_INSTR, 0x40, 0x47, "inc");
SetTableRange(REGISTER_INSTR, 0x48, 0x4F, "dec");
SetTableRange(REGISTER_INSTR, 0x50, 0x57, "push");
SetTableRange(REGISTER_INSTR, 0x58, 0x5F, "pop");
SetTableRange(REGISTER_INSTR, 0x91, 0x97, "xchg eax,"); // 0x90 is nop.
SetTableRange(MOVE_REG_INSTR, 0xB8, 0xBF, "mov");
}
void InstructionTable::CopyTable(ByteMnemonic bm[], InstructionType type) {
for (int i = 0; bm[i].b >= 0; i++) {
InstructionDesc* id = &instructions_[bm[i].b];
id->mnem = bm[i].mnem;
id->op_order_ = bm[i].op_order_;
assert(id->type == NO_INSTR); // Information already entered
id->type = type;
}
}
void InstructionTable::SetTableRange(InstructionType type,
byte start,
byte end,
const char* mnem) {
for (byte b = start; b <= end; b++) {
InstructionDesc* id = &instructions_[b];
assert(id->type == NO_INSTR); // Information already entered
id->mnem = mnem;
id->type = type;
}
}
void InstructionTable::AddJumpConditionalShort() {
for (byte b = 0x70; b <= 0x7F; b++) {
InstructionDesc* id = &instructions_[b];
assert(id->type == NO_INSTR); // Information already entered
id->mnem = jump_conditional_mnem[b & 0x0F];
id->type = JUMP_CONDITIONAL_SHORT_INSTR;
}
}
static InstructionTable instruction_table;
// The IA32 disassembler implementation.
class DisassemblerIA32 {
public:
DisassemblerIA32(const NameConverter& converter,
bool abort_on_unimplemented = true)
: converter_(converter),
tmp_buffer_pos_(0),
abort_on_unimplemented_(abort_on_unimplemented) {
tmp_buffer_[0] = '\0';
}
virtual ~DisassemblerIA32() {}
// 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:
const NameConverter& converter_;
v8::internal::EmbeddedVector<char, 128> tmp_buffer_;
unsigned int tmp_buffer_pos_;
bool abort_on_unimplemented_;
enum {
eax = 0,
ecx = 1,
edx = 2,
ebx = 3,
esp = 4,
ebp = 5,
esi = 6,
edi = 7
};
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.
static void get_modrm(byte data, int* mod, int* regop, int* rm) {
*mod = (data >> 6) & 3;
*regop = (data & 0x38) >> 3;
*rm = data & 7;
}
static void get_sib(byte data, int* scale, int* index, int* base) {
*scale = (data >> 6) & 3;
*index = (data >> 3) & 7;
*base = data & 7;
}
typedef const char* (DisassemblerIA32::*RegisterNameMapping)(int reg) const;
int PrintRightOperandHelper(byte* modrmp, RegisterNameMapping register_name);
int PrintRightOperand(byte* modrmp);
int PrintRightByteOperand(byte* modrmp);
int PrintOperands(const char* mnem, OperandOrder op_order, byte* data);
int PrintImmediateOp(byte* data);
int F7Instruction(byte* data);
int D1D3C1Instruction(byte* data);
int JumpShort(byte* data);
int JumpConditional(byte* data, const char* comment);
int JumpConditionalShort(byte* data, const char* comment);
int SetCC(byte* data);
int FPUInstruction(byte* data);
void AppendToBuffer(const char* format, ...);
void UnimplementedInstruction() {
if (abort_on_unimplemented_) {
UNIMPLEMENTED();
} else {
AppendToBuffer("'Unimplemented Instruction'");
}
}
};
void DisassemblerIA32::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::OS::VSNPrintF(buf, format, args);
va_end(args);
tmp_buffer_pos_ += result;
}
int DisassemblerIA32::PrintRightOperandHelper(
byte* modrmp,
RegisterNameMapping register_name) {
int mod, regop, rm;
get_modrm(*modrmp, &mod, &regop, &rm);
switch (mod) {
case 0:
if (rm == ebp) {
int32_t disp = *reinterpret_cast<int32_t*>(modrmp+1);
AppendToBuffer("[0x%x]", disp);
return 5;
} else if (rm == esp) {
byte sib = *(modrmp + 1);
int scale, index, base;
get_sib(sib, &scale, &index, &base);
if (index == esp && base == esp && scale == 0 /*times_1*/) {
AppendToBuffer("[%s]", (this->*register_name)(rm));
return 2;
} else if (base == ebp) {
int32_t disp = *reinterpret_cast<int32_t*>(modrmp + 2);
AppendToBuffer("[%s*%d+0x%x]",
(this->*register_name)(index),
1 << scale,
disp);
return 6;
} else if (index != esp && base != ebp) {
// [base+index*scale]
AppendToBuffer("[%s+%s*%d]",
(this->*register_name)(base),
(this->*register_name)(index),
1 << scale);
return 2;
} else {
UnimplementedInstruction();
return 1;
}
} else {
AppendToBuffer("[%s]", (this->*register_name)(rm));
return 1;
}
break;
case 1: // fall through
case 2:
if (rm == esp) {
byte sib = *(modrmp + 1);
int scale, index, base;
get_sib(sib, &scale, &index, &base);
int disp =
mod == 2 ? *reinterpret_cast<int32_t*>(modrmp + 2) : *(modrmp + 2);
if (index == base && index == rm /*esp*/ && scale == 0 /*times_1*/) {
AppendToBuffer("[%s+0x%x]", (this->*register_name)(rm), disp);
} else {
AppendToBuffer("[%s+%s*%d+0x%x]",
(this->*register_name)(base),
(this->*register_name)(index),
1 << scale,
disp);
}
return mod == 2 ? 6 : 3;
} else {
// No sib.
int disp =
mod == 2 ? *reinterpret_cast<int32_t*>(modrmp + 1) : *(modrmp + 1);
AppendToBuffer("[%s+0x%x]", (this->*register_name)(rm), disp);
return mod == 2 ? 5 : 2;
}
break;
case 3:
AppendToBuffer("%s", (this->*register_name)(rm));
return 1;
default:
UnimplementedInstruction();
return 1;
}
UNREACHABLE();
}
int DisassemblerIA32::PrintRightOperand(byte* modrmp) {
return PrintRightOperandHelper(modrmp, &DisassemblerIA32::NameOfCPURegister);
}
int DisassemblerIA32::PrintRightByteOperand(byte* modrmp) {
return PrintRightOperandHelper(modrmp,
&DisassemblerIA32::NameOfByteCPURegister);
}
// Returns number of bytes used including the current *data.
// Writes instruction's mnemonic, left and right operands to 'tmp_buffer_'.
int DisassemblerIA32::PrintOperands(const char* mnem,
OperandOrder op_order,
byte* data) {
byte modrm = *data;
int mod, regop, rm;
get_modrm(modrm, &mod, &regop, &rm);
int advance = 0;
switch (op_order) {
case REG_OPER_OP_ORDER: {
AppendToBuffer("%s %s,", mnem, NameOfCPURegister(regop));
advance = PrintRightOperand(data);
break;
}
case OPER_REG_OP_ORDER: {
AppendToBuffer("%s ", mnem);
advance = PrintRightOperand(data);
AppendToBuffer(",%s", NameOfCPURegister(regop));
break;
}
default:
UNREACHABLE();
break;
}
return advance;
}
// Returns number of bytes used by machine instruction, including *data byte.
// Writes immediate instructions to 'tmp_buffer_'.
int DisassemblerIA32::PrintImmediateOp(byte* data) {
bool sign_extension_bit = (*data & 0x02) != 0;
byte 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 4: mnem = "and"; break;
case 5: mnem = "sub"; break;
case 6: mnem = "xor"; break;
case 7: mnem = "cmp"; break;
default: UnimplementedInstruction();
}
AppendToBuffer("%s ", mnem);
int count = PrintRightOperand(data+1);
if (sign_extension_bit) {
AppendToBuffer(",0x%x", *(data + 1 + count));
return 1 + count + 1 /*int8*/;
} else {
AppendToBuffer(",0x%x", *reinterpret_cast<int32_t*>(data + 1 + count));
return 1 + count + 4 /*int32_t*/;
}
}
// Returns number of bytes used, including *data.
int DisassemblerIA32::F7Instruction(byte* data) {
assert(*data == 0xF7);
byte 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 %s", mnem, NameOfCPURegister(rm));
return 2;
} else if (mod == 3 && regop == eax) {
int32_t imm = *reinterpret_cast<int32_t*>(data+2);
AppendToBuffer("test %s,0x%x", NameOfCPURegister(rm), imm);
return 6;
} else if (regop == eax) {
AppendToBuffer("test ");
int count = PrintRightOperand(data+1);
int32_t imm = *reinterpret_cast<int32_t*>(data+1+count);
AppendToBuffer(",0x%x", imm);
return 1+count+4 /*int32_t*/;
} else {
UnimplementedInstruction();
return 2;
}
}
int DisassemblerIA32::D1D3C1Instruction(byte* data) {
byte op = *data;
assert(op == 0xD1 || op == 0xD3 || op == 0xC1);
byte modrm = *(data+1);
int mod, regop, rm;
get_modrm(modrm, &mod, &regop, &rm);
int imm8 = -1;
int num_bytes = 2;
if (mod == 3) {
const char* mnem = NULL;
if (op == 0xD1) {
imm8 = 1;
switch (regop) {
case edx: mnem = "rcl"; break;
case edi: mnem = "sar"; break;
case esp: mnem = "shl"; break;
default: UnimplementedInstruction();
}
} else if (op == 0xC1) {
imm8 = *(data+2);
num_bytes = 3;
switch (regop) {
case edx: mnem = "rcl"; break;
case esp: mnem = "shl"; break;
case ebp: mnem = "shr"; break;
case edi: mnem = "sar"; break;
default: UnimplementedInstruction();
}
} else if (op == 0xD3) {
switch (regop) {
case esp: mnem = "shl"; break;
case ebp: mnem = "shr"; break;
case edi: mnem = "sar"; break;
default: UnimplementedInstruction();
}
}
assert(mnem != NULL);
AppendToBuffer("%s %s,", mnem, NameOfCPURegister(rm));
if (imm8 > 0) {
AppendToBuffer("%d", imm8);
} else {
AppendToBuffer("cl");
}
} else {
UnimplementedInstruction();
}
return num_bytes;
}
// Returns number of bytes used, including *data.
int DisassemblerIA32::JumpShort(byte* data) {
assert(*data == 0xEB);
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 DisassemblerIA32::JumpConditional(byte* data, const char* comment) {
assert(*data == 0x0F);
byte cond = *(data+1) & 0x0F;
byte* dest = data + *reinterpret_cast<int32_t*>(data+2) + 6;
const char* mnem = jump_conditional_mnem[cond];
AppendToBuffer("%s %s", mnem, NameOfAddress(dest));
if (comment != NULL) {
AppendToBuffer(", %s", comment);
}
return 6; // includes 0x0F
}
// Returns number of bytes used, including *data.
int DisassemblerIA32::JumpConditionalShort(byte* data, const char* comment) {
byte cond = *data & 0x0F;
byte b = *(data+1);
byte* dest = data + static_cast<int8_t>(b) + 2;
const char* mnem = jump_conditional_mnem[cond];
AppendToBuffer("%s %s", mnem, NameOfAddress(dest));
if (comment != NULL) {
AppendToBuffer(", %s", comment);
}
return 2;
}
// Returns number of bytes used, including *data.
int DisassemblerIA32::SetCC(byte* data) {
assert(*data == 0x0F);
byte cond = *(data+1) & 0x0F;
const char* mnem = set_conditional_mnem[cond];
AppendToBuffer("%s ", mnem);
PrintRightByteOperand(data+2);
return 3; // includes 0x0F
}
// Returns number of bytes used, including *data.
int DisassemblerIA32::FPUInstruction(byte* data) {
byte b1 = *data;
byte b2 = *(data + 1);
if (b1 == 0xD9) {
const char* mnem = NULL;
switch (b2) {
case 0xE8: mnem = "fld1"; break;
case 0xEE: mnem = "fldz"; break;
case 0xE1: mnem = "fabs"; break;
case 0xE0: mnem = "fchs"; break;
case 0xF8: mnem = "fprem"; break;
case 0xF5: mnem = "fprem1"; break;
case 0xF7: mnem = "fincstp"; break;
case 0xE4: mnem = "ftst"; break;
}
if (mnem != NULL) {
AppendToBuffer("%s", mnem);
return 2;
} else if ((b2 & 0xF8) == 0xC8) {
AppendToBuffer("fxch st%d", b2 & 0x7);
return 2;
} else {
int mod, regop, rm;
get_modrm(*(data+1), &mod, &regop, &rm);
const char* mnem = "?";
switch (regop) {
case eax: mnem = "fld_s"; break;
case ebx: mnem = "fstp_s"; break;
default: UnimplementedInstruction();
}
AppendToBuffer("%s ", mnem);
int count = PrintRightOperand(data + 1);
return count + 1;
}
} else if (b1 == 0xDD) {
if ((b2 & 0xF8) == 0xC0) {
AppendToBuffer("ffree st%d", b2 & 0x7);
return 2;
} else {
int mod, regop, rm;
get_modrm(*(data+1), &mod, &regop, &rm);
const char* mnem = "?";
switch (regop) {
case eax: mnem = "fld_d"; break;
case ebx: mnem = "fstp_d"; break;
default: UnimplementedInstruction();
}
AppendToBuffer("%s ", mnem);
int count = PrintRightOperand(data + 1);
return count + 1;
}
} else if (b1 == 0xDB) {
int mod, regop, rm;
get_modrm(*(data+1), &mod, &regop, &rm);
const char* mnem = "?";
switch (regop) {
case eax: mnem = "fild_s"; break;
case edx: mnem = "fist_s"; break;
case ebx: mnem = "fistp_s"; break;
default: UnimplementedInstruction();
}
AppendToBuffer("%s ", mnem);
int count = PrintRightOperand(data + 1);
return count + 1;
} else if (b1 == 0xDF) {
if (b2 == 0xE0) {
AppendToBuffer("fnstsw_ax");
return 2;
}
int mod, regop, rm;
get_modrm(*(data+1), &mod, &regop, &rm);
const char* mnem = "?";
switch (regop) {
case ebp: mnem = "fild_d"; break;
case edi: mnem = "fistp_d"; break;
default: UnimplementedInstruction();
}
AppendToBuffer("%s ", mnem);
int count = PrintRightOperand(data + 1);
return count + 1;
} else if (b1 == 0xDC || b1 == 0xDE) {
bool is_pop = (b1 == 0xDE);
if (is_pop && b2 == 0xD9) {
AppendToBuffer("fcompp");
return 2;
}
const char* mnem = "FP0xDC";
switch (b2 & 0xF8) {
case 0xC0: mnem = "fadd"; break;
case 0xE8: mnem = "fsub"; break;
case 0xC8: mnem = "fmul"; break;
case 0xF8: mnem = "fdiv"; break;
default: UnimplementedInstruction();
}
AppendToBuffer("%s%s st%d", mnem, is_pop ? "p" : "", b2 & 0x7);
return 2;
} else if (b1 == 0xDA && b2 == 0xE9) {
const char* mnem = "fucompp";
AppendToBuffer("%s", mnem);
return 2;
}
AppendToBuffer("Unknown FP instruction");
return 2;
}
// Mnemonics for instructions 0xF0 byte.
// Returns NULL if the instruction is not handled here.
static const char* F0Mnem(byte f0byte) {
switch (f0byte) {
case 0xA2: return "cpuid";
case 0x31: return "rdtsc";
case 0xBE: return "movsx_b";
case 0xBF: return "movsx_w";
case 0xB6: return "movzx_b";
case 0xB7: return "movzx_w";
case 0xAF: return "imul";
case 0xA5: return "shld";
case 0xAD: return "shrd";
case 0xAB: return "bts";
default: return NULL;
}
}
// Disassembled instruction '*instr' and writes it into 'out_buffer'.
int DisassemblerIA32::InstructionDecode(v8::internal::Vector<char> out_buffer,
byte* instr) {
tmp_buffer_pos_ = 0; // starting to write as position 0
byte* data = instr;
// Check for hints.
const char* branch_hint = NULL;
// We use these two prefixes only with branch prediction
if (*data == 0x3E /*ds*/) {
branch_hint = "predicted taken";
data++;
} else if (*data == 0x2E /*cs*/) {
branch_hint = "predicted not taken";
data++;
}
bool processed = true; // Will be set to false if the current instruction
// is not in 'instructions' table.
const InstructionDesc& idesc = instruction_table.Get(*data);
switch (idesc.type) {
case ZERO_OPERANDS_INSTR:
AppendToBuffer(idesc.mnem);
data++;
break;
case TWO_OPERANDS_INSTR:
data++;
data += PrintOperands(idesc.mnem, idesc.op_order_, data);
break;
case JUMP_CONDITIONAL_SHORT_INSTR:
data += JumpConditionalShort(data, branch_hint);
break;
case REGISTER_INSTR:
AppendToBuffer("%s %s", idesc.mnem, NameOfCPURegister(*data & 0x07));
data++;
break;
case MOVE_REG_INSTR: {
byte* addr = reinterpret_cast<byte*>(*reinterpret_cast<int32_t*>(data+1));
AppendToBuffer("mov %s,%s",
NameOfCPURegister(*data & 0x07),
NameOfAddress(addr));
data += 5;
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 eax, %s", idesc.mnem, NameOfAddress(addr));
data += 5;
break;
}
case NO_INSTR:
processed = false;
break;
default:
UNIMPLEMENTED(); // This type is not implemented.
}
//----------------------------
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, &regop, &rm);
int32_t imm =
*data == 0x6B ? *(data+2) : *reinterpret_cast<int32_t*>(data+2);
AppendToBuffer("imul %s,%s,0x%x",
NameOfCPURegister(regop),
NameOfCPURegister(rm),
imm);
data += 2 + (*data == 0x6B ? 1 : 4);
}
break;
case 0xF6:
{ int mod, regop, rm;
get_modrm(*(data+1), &mod, &regop, &rm);
if (mod == 3 && regop == eax) {
AppendToBuffer("test_b %s,%d", NameOfCPURegister(rm), *(data+2));
} else {
UnimplementedInstruction();
}
data += 3;
}
break;
case 0x81: // fall through
case 0x83: // 0x81 with sign extension bit set
data += PrintImmediateOp(data);
break;
case 0x0F:
{ byte f0byte = *(data+1);
const char* f0mnem = F0Mnem(f0byte);
if (f0byte == 0xA2 || f0byte == 0x31) {
AppendToBuffer("%s", f0mnem);
data += 2;
} else if ((f0byte & 0xF0) == 0x80) {
data += JumpConditional(data, branch_hint);
} else if (f0byte == 0xBE || f0byte == 0xBF || f0byte == 0xB6 ||
f0byte == 0xB7 || f0byte == 0xAF) {
data += 2;
data += PrintOperands(f0mnem, REG_OPER_OP_ORDER, data);
} else if ((f0byte & 0xF0) == 0x90) {
data += SetCC(data);
} else {
data += 2;
if (f0byte == 0xAB || f0byte == 0xA5 || f0byte == 0xAD) {
// shrd, shld, bts
AppendToBuffer("%s ", f0mnem);
int mod, regop, rm;
get_modrm(*data, &mod, &regop, &rm);
data += PrintRightOperand(data);
if (f0byte == 0xAB) {
AppendToBuffer(",%s", NameOfCPURegister(regop));
} else {
AppendToBuffer(",%s,cl", NameOfCPURegister(regop));
}
} else {
UnimplementedInstruction();
}
}
}
break;
case 0x8F:
{ data++;
int mod, regop, rm;
get_modrm(*data, &mod, &regop, &rm);
if (regop == eax) {
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 esi: mnem = "push"; break;
case eax: mnem = "inc"; break;
case ecx: mnem = "dec"; break;
case edx: mnem = "call"; break;
case esp: mnem = "jmp"; break;
default: mnem = "???";
}
AppendToBuffer("%s ", mnem);
data += PrintRightOperand(data);
}
break;
case 0xC7: // imm32, fall through
case 0xC6: // imm8
{ bool is_byte = *data == 0xC6;
data++;
AppendToBuffer("%s ", is_byte ? "mov_b" : "mov");
data += PrintRightOperand(data);
int32_t imm = is_byte ? *data : *reinterpret_cast<int32_t*>(data);
AppendToBuffer(",0x%x", imm);
data += is_byte ? 1 : 4;
}
break;
case 0x80:
{ data++;
AppendToBuffer("%s ", "cmpb");
data += PrintRightOperand(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, &regop, &rm);
AppendToBuffer("%s ", is_byte ? "mov_b" : "mov");
data += PrintRightOperand(data);
AppendToBuffer(",%s", NameOfCPURegister(regop));
}
break;
case 0x66: // prefix
data++;
if (*data == 0x8B) {
data++;
data += PrintOperands("mov_w", REG_OPER_OP_ORDER, data);
} else if (*data == 0x89) {
data++;
int mod, regop, rm;
get_modrm(*data, &mod, &regop, &rm);
AppendToBuffer("mov_w ");
data += PrintRightOperand(data);
AppendToBuffer(",%s", NameOfCPURegister(regop));
} else {
UnimplementedInstruction();
}
break;
case 0xFE:
{ data++;
int mod, regop, rm;
get_modrm(*data, &mod, &regop, &rm);
if (mod == 3 && regop == ecx) {
AppendToBuffer("dec_b %s", NameOfCPURegister(rm));
} else {
UnimplementedInstruction();
}
data++;
}
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 0xA8:
AppendToBuffer("test al,0x%x", *reinterpret_cast<uint8_t*>(data+1));
data += 2;
break;
case 0xA9:
AppendToBuffer("test eax,0x%x", *reinterpret_cast<int32_t*>(data+1));
data += 5;
break;
case 0xD1: // fall through
case 0xD3: // fall through
case 0xC1:
data += D1D3C1Instruction(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 0xF2:
if (*(data+1) == 0x0F) {
byte b2 = *(data+2);
if (b2 == 0x11) {
AppendToBuffer("movsd ");
data += 3;
int mod, regop, rm;
get_modrm(*data, &mod, &regop, &rm);
data += PrintRightOperand(data);
AppendToBuffer(",%s", NameOfXMMRegister(regop));
} else if (b2 == 0x10) {
data += 3;
int mod, regop, rm;
get_modrm(*data, &mod, &regop, &rm);
AppendToBuffer("movsd %s,", NameOfXMMRegister(regop));
data += PrintRightOperand(data);
} else {
const char* mnem = "?";
switch (b2) {
case 0x2A: mnem = "cvtsi2sd"; break;
case 0x58: mnem = "addsd"; break;
case 0x59: mnem = "mulsd"; break;
case 0x5C: mnem = "subsd"; break;
case 0x5E: mnem = "divsd"; break;
}
data += 3;
int mod, regop, rm;
get_modrm(*data, &mod, &regop, &rm);
if (b2 == 0x2A) {
AppendToBuffer("%s %s,", mnem, NameOfXMMRegister(regop));
data += PrintRightOperand(data);
} else {
AppendToBuffer("%s %s,%s",
mnem,
NameOfXMMRegister(regop),
NameOfXMMRegister(rm));
data++;
}
}
} else {
UnimplementedInstruction();
}
break;
case 0xF3:
if (*(data+1) == 0x0F && *(data+2) == 0x2C) {
data += 3;
data += PrintOperands("cvttss2si", REG_OPER_OP_ORDER, data);
} else {
UnimplementedInstruction();
}
break;
case 0xF7:
data += F7Instruction(data);
break;
default:
UnimplementedInstruction();
}
}
if (tmp_buffer_pos_ < sizeof tmp_buffer_) {
tmp_buffer_[tmp_buffer_pos_] = '\0';
}
int instr_len = data - instr;
ASSERT(instr_len > 0); // Ensure progress.
int outp = 0;
// Instruction bytes.
for (byte* bp = instr; bp < data; bp++) {
outp += v8::internal::OS::SNPrintF(out_buffer + outp,
"%02x",
*bp);
}
for (int i = 6 - instr_len; i >= 0; i--) {
outp += v8::internal::OS::SNPrintF(out_buffer + outp,
" ");
}
outp += v8::internal::OS::SNPrintF(out_buffer + outp,
" %s",
tmp_buffer_.start());
return instr_len;
}
//------------------------------------------------------------------------------
static const char* cpu_regs[8] = {
"eax", "ecx", "edx", "ebx", "esp", "ebp", "esi", "edi"
};
static const char* byte_cpu_regs[8] = {
"al", "cl", "dl", "bl", "ah", "ch", "dh", "bh"
};
static const char* xmm_regs[8] = {
"xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5", "xmm6", "xmm7"
};
const char* NameConverter::NameOfAddress(byte* addr) const {
static v8::internal::EmbeddedVector<char, 32> tmp_buffer;
v8::internal::OS::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 < 8) return cpu_regs[reg];
return "noreg";
}
const char* NameConverter::NameOfByteCPURegister(int reg) const {
if (0 <= reg && reg < 8) return byte_cpu_regs[reg];
return "noreg";
}
const char* NameConverter::NameOfXMMRegister(int reg) const {
if (0 <= reg && reg < 8) return xmm_regs[reg];
return "noxmmreg";
}
const char* NameConverter::NameInCode(byte* addr) const {
// IA32 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) {
DisassemblerIA32 d(converter_, false /*do not crash if unimplemented*/);
return d.InstructionDecode(buffer, instruction);
}
// The IA-32 assembler does not currently use constant pools.
int Disassembler::ConstantPoolSizeAt(byte* instruction) { return -1; }
/*static*/ 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 - (pc - prev_pc); i >= 0; i--) {
fprintf(f, " ");
}
fprintf(f, " %s\n", buffer.start());
}
}
} // namespace disasm
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