// Copyright 2011 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.
// A Disassembler object is used to disassemble a block of code instruction by
// instruction. The default implementation of the NameConverter object can be
// overriden to modify register names or to do symbol lookup on addresses.
//
// The example below will disassemble a block of code and print it to stdout.
//
// NameConverter converter;
// Disassembler d(converter);
// for (byte* pc = begin; pc < end;) {
// v8::internal::EmbeddedVector<char, 256> buffer;
// byte* prev_pc = pc;
// pc += d.InstructionDecode(buffer, pc);
// printf("%p %08x %s\n",
// prev_pc, *reinterpret_cast<int32_t*>(prev_pc), buffer);
// }
//
// The Disassembler class also has a convenience method to disassemble a block
// of code into a FILE*, meaning that the above functionality could also be
// achieved by just calling Disassembler::Disassemble(stdout, begin, end);
#include <assert.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#ifndef WIN32
#include <stdint.h>
#endif
#include "v8.h"
#if defined(V8_TARGET_ARCH_ARM)
#include "constants-arm.h"
#include "disasm.h"
#include "macro-assembler.h"
#include "platform.h"
namespace v8 {
namespace internal {
//------------------------------------------------------------------------------
// Decoder decodes and disassembles instructions into an output buffer.
// It uses the converter to convert register names and call destinations into
// more informative description.
class Decoder {
public:
Decoder(const disasm::NameConverter& converter,
Vector<char> out_buffer)
: converter_(converter),
out_buffer_(out_buffer),
out_buffer_pos_(0) {
out_buffer_[out_buffer_pos_] = '\0';
}
~Decoder() {}
// Writes one disassembled instruction into 'buffer' (0-terminated).
// Returns the length of the disassembled machine instruction in bytes.
int InstructionDecode(byte* instruction);
static bool IsConstantPoolAt(byte* instr_ptr);
static int ConstantPoolSizeAt(byte* instr_ptr);
private:
// Bottleneck functions to print into the out_buffer.
void PrintChar(const char ch);
void Print(const char* str);
// Printing of common values.
void PrintRegister(int reg);
void PrintSRegister(int reg);
void PrintDRegister(int reg);
int FormatVFPRegister(Instruction* instr, const char* format);
void PrintMovwMovt(Instruction* instr);
int FormatVFPinstruction(Instruction* instr, const char* format);
void PrintCondition(Instruction* instr);
void PrintShiftRm(Instruction* instr);
void PrintShiftImm(Instruction* instr);
void PrintShiftSat(Instruction* instr);
void PrintPU(Instruction* instr);
void PrintSoftwareInterrupt(SoftwareInterruptCodes svc);
// Handle formatting of instructions and their options.
int FormatRegister(Instruction* instr, const char* option);
int FormatOption(Instruction* instr, const char* option);
void Format(Instruction* instr, const char* format);
void Unknown(Instruction* instr);
// Each of these functions decodes one particular instruction type, a 3-bit
// field in the instruction encoding.
// Types 0 and 1 are combined as they are largely the same except for the way
// they interpret the shifter operand.
void DecodeType01(Instruction* instr);
void DecodeType2(Instruction* instr);
void DecodeType3(Instruction* instr);
void DecodeType4(Instruction* instr);
void DecodeType5(Instruction* instr);
void DecodeType6(Instruction* instr);
// Type 7 includes special Debugger instructions.
int DecodeType7(Instruction* instr);
// For VFP support.
void DecodeTypeVFP(Instruction* instr);
void DecodeType6CoprocessorIns(Instruction* instr);
void DecodeVMOVBetweenCoreAndSinglePrecisionRegisters(Instruction* instr);
void DecodeVCMP(Instruction* instr);
void DecodeVCVTBetweenDoubleAndSingle(Instruction* instr);
void DecodeVCVTBetweenFloatingPointAndInteger(Instruction* instr);
const disasm::NameConverter& converter_;
Vector<char> out_buffer_;
int out_buffer_pos_;
DISALLOW_COPY_AND_ASSIGN(Decoder);
};
// Support for assertions in the Decoder formatting functions.
#define STRING_STARTS_WITH(string, compare_string) \
(strncmp(string, compare_string, strlen(compare_string)) == 0)
// Append the ch to the output buffer.
void Decoder::PrintChar(const char ch) {
out_buffer_[out_buffer_pos_++] = ch;
}
// Append the str to the output buffer.
void Decoder::Print(const char* str) {
char cur = *str++;
while (cur != '\0' && (out_buffer_pos_ < (out_buffer_.length() - 1))) {
PrintChar(cur);
cur = *str++;
}
out_buffer_[out_buffer_pos_] = 0;
}
// These condition names are defined in a way to match the native disassembler
// formatting. See for example the command "objdump -d <binary file>".
static const char* cond_names[kNumberOfConditions] = {
"eq", "ne", "cs" , "cc" , "mi" , "pl" , "vs" , "vc" ,
"hi", "ls", "ge", "lt", "gt", "le", "", "invalid",
};
// Print the condition guarding the instruction.
void Decoder::PrintCondition(Instruction* instr) {
Print(cond_names[instr->ConditionValue()]);
}
// Print the register name according to the active name converter.
void Decoder::PrintRegister(int reg) {
Print(converter_.NameOfCPURegister(reg));
}
// Print the VFP S register name according to the active name converter.
void Decoder::PrintSRegister(int reg) {
Print(VFPRegisters::Name(reg, false));
}
// Print the VFP D register name according to the active name converter.
void Decoder::PrintDRegister(int reg) {
Print(VFPRegisters::Name(reg, true));
}
// These shift names are defined in a way to match the native disassembler
// formatting. See for example the command "objdump -d <binary file>".
static const char* const shift_names[kNumberOfShifts] = {
"lsl", "lsr", "asr", "ror"
};
// Print the register shift operands for the instruction. Generally used for
// data processing instructions.
void Decoder::PrintShiftRm(Instruction* instr) {
ShiftOp shift = instr->ShiftField();
int shift_index = instr->ShiftValue();
int shift_amount = instr->ShiftAmountValue();
int rm = instr->RmValue();
PrintRegister(rm);
if ((instr->RegShiftValue() == 0) && (shift == LSL) && (shift_amount == 0)) {
// Special case for using rm only.
return;
}
if (instr->RegShiftValue() == 0) {
// by immediate
if ((shift == ROR) && (shift_amount == 0)) {
Print(", RRX");
return;
} else if (((shift == LSR) || (shift == ASR)) && (shift_amount == 0)) {
shift_amount = 32;
}
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
", %s #%d",
shift_names[shift_index],
shift_amount);
} else {
// by register
int rs = instr->RsValue();
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
", %s ", shift_names[shift_index]);
PrintRegister(rs);
}
}
// Print the immediate operand for the instruction. Generally used for data
// processing instructions.
void Decoder::PrintShiftImm(Instruction* instr) {
int rotate = instr->RotateValue() * 2;
int immed8 = instr->Immed8Value();
int imm = (immed8 >> rotate) | (immed8 << (32 - rotate));
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
"#%d", imm);
}
// Print the optional shift and immediate used by saturating instructions.
void Decoder::PrintShiftSat(Instruction* instr) {
int shift = instr->Bits(11, 7);
if (shift > 0) {
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
", %s #%d",
shift_names[instr->Bit(6) * 2],
instr->Bits(11, 7));
}
}
// Print PU formatting to reduce complexity of FormatOption.
void Decoder::PrintPU(Instruction* instr) {
switch (instr->PUField()) {
case da_x: {
Print("da");
break;
}
case ia_x: {
Print("ia");
break;
}
case db_x: {
Print("db");
break;
}
case ib_x: {
Print("ib");
break;
}
default: {
UNREACHABLE();
break;
}
}
}
// Print SoftwareInterrupt codes. Factoring this out reduces the complexity of
// the FormatOption method.
void Decoder::PrintSoftwareInterrupt(SoftwareInterruptCodes svc) {
switch (svc) {
case kCallRtRedirected:
Print("call rt redirected");
return;
case kBreakpoint:
Print("breakpoint");
return;
default:
if (svc >= kStopCode) {
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
"%d - 0x%x",
svc & kStopCodeMask,
svc & kStopCodeMask);
} else {
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
"%d",
svc);
}
return;
}
}
// Handle all register based formatting in this function to reduce the
// complexity of FormatOption.
int Decoder::FormatRegister(Instruction* instr, const char* format) {
ASSERT(format[0] == 'r');
if (format[1] == 'n') { // 'rn: Rn register
int reg = instr->RnValue();
PrintRegister(reg);
return 2;
} else if (format[1] == 'd') { // 'rd: Rd register
int reg = instr->RdValue();
PrintRegister(reg);
return 2;
} else if (format[1] == 's') { // 'rs: Rs register
int reg = instr->RsValue();
PrintRegister(reg);
return 2;
} else if (format[1] == 'm') { // 'rm: Rm register
int reg = instr->RmValue();
PrintRegister(reg);
return 2;
} else if (format[1] == 't') { // 'rt: Rt register
int reg = instr->RtValue();
PrintRegister(reg);
return 2;
} else if (format[1] == 'l') {
// 'rlist: register list for load and store multiple instructions
ASSERT(STRING_STARTS_WITH(format, "rlist"));
int rlist = instr->RlistValue();
int reg = 0;
Print("{");
// Print register list in ascending order, by scanning the bit mask.
while (rlist != 0) {
if ((rlist & 1) != 0) {
PrintRegister(reg);
if ((rlist >> 1) != 0) {
Print(", ");
}
}
reg++;
rlist >>= 1;
}
Print("}");
return 5;
}
UNREACHABLE();
return -1;
}
// Handle all VFP register based formatting in this function to reduce the
// complexity of FormatOption.
int Decoder::FormatVFPRegister(Instruction* instr, const char* format) {
ASSERT((format[0] == 'S') || (format[0] == 'D'));
VFPRegPrecision precision =
format[0] == 'D' ? kDoublePrecision : kSinglePrecision;
int retval = 2;
int reg = -1;
if (format[1] == 'n') {
reg = instr->VFPNRegValue(precision);
} else if (format[1] == 'm') {
reg = instr->VFPMRegValue(precision);
} else if (format[1] == 'd') {
reg = instr->VFPDRegValue(precision);
if (format[2] == '+') {
int immed8 = instr->Immed8Value();
if (format[0] == 'S') reg += immed8 - 1;
if (format[0] == 'D') reg += (immed8 / 2 - 1);
}
if (format[2] == '+') retval = 3;
} else {
UNREACHABLE();
}
if (precision == kSinglePrecision) {
PrintSRegister(reg);
} else {
PrintDRegister(reg);
}
return retval;
}
int Decoder::FormatVFPinstruction(Instruction* instr, const char* format) {
Print(format);
return 0;
}
// Print the movw or movt instruction.
void Decoder::PrintMovwMovt(Instruction* instr) {
int imm = instr->ImmedMovwMovtValue();
int rd = instr->RdValue();
PrintRegister(rd);
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
", #%d", imm);
}
// FormatOption takes a formatting string and interprets it based on
// the current instructions. The format string points to the first
// character of the option string (the option escape has already been
// consumed by the caller.) FormatOption returns the number of
// characters that were consumed from the formatting string.
int Decoder::FormatOption(Instruction* instr, const char* format) {
switch (format[0]) {
case 'a': { // 'a: accumulate multiplies
if (instr->Bit(21) == 0) {
Print("ul");
} else {
Print("la");
}
return 1;
}
case 'b': { // 'b: byte loads or stores
if (instr->HasB()) {
Print("b");
}
return 1;
}
case 'c': { // 'cond: conditional execution
ASSERT(STRING_STARTS_WITH(format, "cond"));
PrintCondition(instr);
return 4;
}
case 'd': { // 'd: vmov double immediate.
double d = instr->DoubleImmedVmov();
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
"#%g", d);
return 1;
}
case 'f': { // 'f: bitfield instructions - v7 and above.
uint32_t lsbit = instr->Bits(11, 7);
uint32_t width = instr->Bits(20, 16) + 1;
if (instr->Bit(21) == 0) {
// BFC/BFI:
// Bits 20-16 represent most-significant bit. Covert to width.
width -= lsbit;
ASSERT(width > 0);
}
ASSERT((width + lsbit) <= 32);
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
"#%d, #%d", lsbit, width);
return 1;
}
case 'h': { // 'h: halfword operation for extra loads and stores
if (instr->HasH()) {
Print("h");
} else {
Print("b");
}
return 1;
}
case 'i': { // 'i: immediate value from adjacent bits.
// Expects tokens in the form imm%02d@%02d, i.e. imm05@07, imm10@16
int width = (format[3] - '0') * 10 + (format[4] - '0');
int lsb = (format[6] - '0') * 10 + (format[7] - '0');
ASSERT((width >= 1) && (width <= 32));
ASSERT((lsb >= 0) && (lsb <= 31));
ASSERT((width + lsb) <= 32);
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
"%d",
instr->Bits(width + lsb - 1, lsb));
return 8;
}
case 'l': { // 'l: branch and link
if (instr->HasLink()) {
Print("l");
}
return 1;
}
case 'm': {
if (format[1] == 'w') {
// 'mw: movt/movw instructions.
PrintMovwMovt(instr);
return 2;
}
if (format[1] == 'e') { // 'memop: load/store instructions.
ASSERT(STRING_STARTS_WITH(format, "memop"));
if (instr->HasL()) {
Print("ldr");
} else {
if ((instr->Bits(27, 25) == 0) && (instr->Bit(20) == 0) &&
(instr->Bits(7, 6) == 3) && (instr->Bit(4) == 1)) {
if (instr->Bit(5) == 1) {
Print("strd");
} else {
Print("ldrd");
}
return 5;
}
Print("str");
}
return 5;
}
// 'msg: for simulator break instructions
ASSERT(STRING_STARTS_WITH(format, "msg"));
byte* str =
reinterpret_cast<byte*>(instr->InstructionBits() & 0x0fffffff);
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
"%s", converter_.NameInCode(str));
return 3;
}
case 'o': {
if ((format[3] == '1') && (format[4] == '2')) {
// 'off12: 12-bit offset for load and store instructions
ASSERT(STRING_STARTS_WITH(format, "off12"));
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
"%d", instr->Offset12Value());
return 5;
} else if (format[3] == '0') {
// 'off0to3and8to19 16-bit immediate encoded in bits 19-8 and 3-0.
ASSERT(STRING_STARTS_WITH(format, "off0to3and8to19"));
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
"%d",
(instr->Bits(19, 8) << 4) +
instr->Bits(3, 0));
return 15;
}
// 'off8: 8-bit offset for extra load and store instructions
ASSERT(STRING_STARTS_WITH(format, "off8"));
int offs8 = (instr->ImmedHValue() << 4) | instr->ImmedLValue();
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
"%d", offs8);
return 4;
}
case 'p': { // 'pu: P and U bits for load and store instructions
ASSERT(STRING_STARTS_WITH(format, "pu"));
PrintPU(instr);
return 2;
}
case 'r': {
return FormatRegister(instr, format);
}
case 's': {
if (format[1] == 'h') { // 'shift_op or 'shift_rm or 'shift_sat.
if (format[6] == 'o') { // 'shift_op
ASSERT(STRING_STARTS_WITH(format, "shift_op"));
if (instr->TypeValue() == 0) {
PrintShiftRm(instr);
} else {
ASSERT(instr->TypeValue() == 1);
PrintShiftImm(instr);
}
return 8;
} else if (format[6] == 's') { // 'shift_sat.
ASSERT(STRING_STARTS_WITH(format, "shift_sat"));
PrintShiftSat(instr);
return 9;
} else { // 'shift_rm
ASSERT(STRING_STARTS_WITH(format, "shift_rm"));
PrintShiftRm(instr);
return 8;
}
} else if (format[1] == 'v') { // 'svc
ASSERT(STRING_STARTS_WITH(format, "svc"));
PrintSoftwareInterrupt(instr->SvcValue());
return 3;
} else if (format[1] == 'i') { // 'sign: signed extra loads and stores
ASSERT(STRING_STARTS_WITH(format, "sign"));
if (instr->HasSign()) {
Print("s");
}
return 4;
}
// 's: S field of data processing instructions
if (instr->HasS()) {
Print("s");
}
return 1;
}
case 't': { // 'target: target of branch instructions
ASSERT(STRING_STARTS_WITH(format, "target"));
int off = (instr->SImmed24Value() << 2) + 8;
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
"%+d -> %s",
off,
converter_.NameOfAddress(
reinterpret_cast<byte*>(instr) + off));
return 6;
}
case 'u': { // 'u: signed or unsigned multiplies
// The manual gets the meaning of bit 22 backwards in the multiply
// instruction overview on page A3.16.2. The instructions that
// exist in u and s variants are the following:
// smull A4.1.87
// umull A4.1.129
// umlal A4.1.128
// smlal A4.1.76
// For these 0 means u and 1 means s. As can be seen on their individual
// pages. The other 18 mul instructions have the bit set or unset in
// arbitrary ways that are unrelated to the signedness of the instruction.
// None of these 18 instructions exist in both a 'u' and an 's' variant.
if (instr->Bit(22) == 0) {
Print("u");
} else {
Print("s");
}
return 1;
}
case 'v': {
return FormatVFPinstruction(instr, format);
}
case 'S':
case 'D': {
return FormatVFPRegister(instr, format);
}
case 'w': { // 'w: W field of load and store instructions
if (instr->HasW()) {
Print("!");
}
return 1;
}
default: {
UNREACHABLE();
break;
}
}
UNREACHABLE();
return -1;
}
// Format takes a formatting string for a whole instruction and prints it into
// the output buffer. All escaped options are handed to FormatOption to be
// parsed further.
void Decoder::Format(Instruction* instr, const char* format) {
char cur = *format++;
while ((cur != 0) && (out_buffer_pos_ < (out_buffer_.length() - 1))) {
if (cur == '\'') { // Single quote is used as the formatting escape.
format += FormatOption(instr, format);
} else {
out_buffer_[out_buffer_pos_++] = cur;
}
cur = *format++;
}
out_buffer_[out_buffer_pos_] = '\0';
}
// The disassembler may end up decoding data inlined in the code. We do not want
// it to crash if the data does not ressemble any known instruction.
#define VERIFY(condition) \
if(!(condition)) { \
Unknown(instr); \
return; \
}
// For currently unimplemented decodings the disassembler calls Unknown(instr)
// which will just print "unknown" of the instruction bits.
void Decoder::Unknown(Instruction* instr) {
Format(instr, "unknown");
}
void Decoder::DecodeType01(Instruction* instr) {
int type = instr->TypeValue();
if ((type == 0) && instr->IsSpecialType0()) {
// multiply instruction or extra loads and stores
if (instr->Bits(7, 4) == 9) {
if (instr->Bit(24) == 0) {
// multiply instructions
if (instr->Bit(23) == 0) {
if (instr->Bit(21) == 0) {
// The MUL instruction description (A 4.1.33) refers to Rd as being
// the destination for the operation, but it confusingly uses the
// Rn field to encode it.
Format(instr, "mul'cond's 'rn, 'rm, 'rs");
} else {
// The MLA instruction description (A 4.1.28) refers to the order
// of registers as "Rd, Rm, Rs, Rn". But confusingly it uses the
// Rn field to encode the Rd register and the Rd field to encode
// the Rn register.
Format(instr, "mla'cond's 'rn, 'rm, 'rs, 'rd");
}
} else {
// The signed/long multiply instructions use the terms RdHi and RdLo
// when referring to the target registers. They are mapped to the Rn
// and Rd fields as follows:
// RdLo == Rd field
// RdHi == Rn field
// The order of registers is: <RdLo>, <RdHi>, <Rm>, <Rs>
Format(instr, "'um'al'cond's 'rd, 'rn, 'rm, 'rs");
}
} else {
Unknown(instr); // not used by V8
}
} else if ((instr->Bit(20) == 0) && ((instr->Bits(7, 4) & 0xd) == 0xd)) {
// ldrd, strd
switch (instr->PUField()) {
case da_x: {
if (instr->Bit(22) == 0) {
Format(instr, "'memop'cond's 'rd, ['rn], -'rm");
} else {
Format(instr, "'memop'cond's 'rd, ['rn], #-'off8");
}
break;
}
case ia_x: {
if (instr->Bit(22) == 0) {
Format(instr, "'memop'cond's 'rd, ['rn], +'rm");
} else {
Format(instr, "'memop'cond's 'rd, ['rn], #+'off8");
}
break;
}
case db_x: {
if (instr->Bit(22) == 0) {
Format(instr, "'memop'cond's 'rd, ['rn, -'rm]'w");
} else {
Format(instr, "'memop'cond's 'rd, ['rn, #-'off8]'w");
}
break;
}
case ib_x: {
if (instr->Bit(22) == 0) {
Format(instr, "'memop'cond's 'rd, ['rn, +'rm]'w");
} else {
Format(instr, "'memop'cond's 'rd, ['rn, #+'off8]'w");
}
break;
}
default: {
// The PU field is a 2-bit field.
UNREACHABLE();
break;
}
}
} else {
// extra load/store instructions
switch (instr->PUField()) {
case da_x: {
if (instr->Bit(22) == 0) {
Format(instr, "'memop'cond'sign'h 'rd, ['rn], -'rm");
} else {
Format(instr, "'memop'cond'sign'h 'rd, ['rn], #-'off8");
}
break;
}
case ia_x: {
if (instr->Bit(22) == 0) {
Format(instr, "'memop'cond'sign'h 'rd, ['rn], +'rm");
} else {
Format(instr, "'memop'cond'sign'h 'rd, ['rn], #+'off8");
}
break;
}
case db_x: {
if (instr->Bit(22) == 0) {
Format(instr, "'memop'cond'sign'h 'rd, ['rn, -'rm]'w");
} else {
Format(instr, "'memop'cond'sign'h 'rd, ['rn, #-'off8]'w");
}
break;
}
case ib_x: {
if (instr->Bit(22) == 0) {
Format(instr, "'memop'cond'sign'h 'rd, ['rn, +'rm]'w");
} else {
Format(instr, "'memop'cond'sign'h 'rd, ['rn, #+'off8]'w");
}
break;
}
default: {
// The PU field is a 2-bit field.
UNREACHABLE();
break;
}
}
return;
}
} else if ((type == 0) && instr->IsMiscType0()) {
if (instr->Bits(22, 21) == 1) {
switch (instr->BitField(7, 4)) {
case BX:
Format(instr, "bx'cond 'rm");
break;
case BLX:
Format(instr, "blx'cond 'rm");
break;
case BKPT:
Format(instr, "bkpt 'off0to3and8to19");
break;
default:
Unknown(instr); // not used by V8
break;
}
} else if (instr->Bits(22, 21) == 3) {
switch (instr->BitField(7, 4)) {
case CLZ:
Format(instr, "clz'cond 'rd, 'rm");
break;
default:
Unknown(instr); // not used by V8
break;
}
} else {
Unknown(instr); // not used by V8
}
} else {
switch (instr->OpcodeField()) {
case AND: {
Format(instr, "and'cond's 'rd, 'rn, 'shift_op");
break;
}
case EOR: {
Format(instr, "eor'cond's 'rd, 'rn, 'shift_op");
break;
}
case SUB: {
Format(instr, "sub'cond's 'rd, 'rn, 'shift_op");
break;
}
case RSB: {
Format(instr, "rsb'cond's 'rd, 'rn, 'shift_op");
break;
}
case ADD: {
Format(instr, "add'cond's 'rd, 'rn, 'shift_op");
break;
}
case ADC: {
Format(instr, "adc'cond's 'rd, 'rn, 'shift_op");
break;
}
case SBC: {
Format(instr, "sbc'cond's 'rd, 'rn, 'shift_op");
break;
}
case RSC: {
Format(instr, "rsc'cond's 'rd, 'rn, 'shift_op");
break;
}
case TST: {
if (instr->HasS()) {
Format(instr, "tst'cond 'rn, 'shift_op");
} else {
Format(instr, "movw'cond 'mw");
}
break;
}
case TEQ: {
if (instr->HasS()) {
Format(instr, "teq'cond 'rn, 'shift_op");
} else {
// Other instructions matching this pattern are handled in the
// miscellaneous instructions part above.
UNREACHABLE();
}
break;
}
case CMP: {
if (instr->HasS()) {
Format(instr, "cmp'cond 'rn, 'shift_op");
} else {
Format(instr, "movt'cond 'mw");
}
break;
}
case CMN: {
if (instr->HasS()) {
Format(instr, "cmn'cond 'rn, 'shift_op");
} else {
// Other instructions matching this pattern are handled in the
// miscellaneous instructions part above.
UNREACHABLE();
}
break;
}
case ORR: {
Format(instr, "orr'cond's 'rd, 'rn, 'shift_op");
break;
}
case MOV: {
Format(instr, "mov'cond's 'rd, 'shift_op");
break;
}
case BIC: {
Format(instr, "bic'cond's 'rd, 'rn, 'shift_op");
break;
}
case MVN: {
Format(instr, "mvn'cond's 'rd, 'shift_op");
break;
}
default: {
// The Opcode field is a 4-bit field.
UNREACHABLE();
break;
}
}
}
}
void Decoder::DecodeType2(Instruction* instr) {
switch (instr->PUField()) {
case da_x: {
if (instr->HasW()) {
Unknown(instr); // not used in V8
return;
}
Format(instr, "'memop'cond'b 'rd, ['rn], #-'off12");
break;
}
case ia_x: {
if (instr->HasW()) {
Unknown(instr); // not used in V8
return;
}
Format(instr, "'memop'cond'b 'rd, ['rn], #+'off12");
break;
}
case db_x: {
Format(instr, "'memop'cond'b 'rd, ['rn, #-'off12]'w");
break;
}
case ib_x: {
Format(instr, "'memop'cond'b 'rd, ['rn, #+'off12]'w");
break;
}
default: {
// The PU field is a 2-bit field.
UNREACHABLE();
break;
}
}
}
void Decoder::DecodeType3(Instruction* instr) {
switch (instr->PUField()) {
case da_x: {
VERIFY(!instr->HasW());
Format(instr, "'memop'cond'b 'rd, ['rn], -'shift_rm");
break;
}
case ia_x: {
if (instr->HasW()) {
VERIFY(instr->Bits(5, 4) == 0x1);
if (instr->Bit(22) == 0x1) {
Format(instr, "usat 'rd, #'imm05@16, 'rm'shift_sat");
} else {
UNREACHABLE(); // SSAT.
}
} else {
Format(instr, "'memop'cond'b 'rd, ['rn], +'shift_rm");
}
break;
}
case db_x: {
Format(instr, "'memop'cond'b 'rd, ['rn, -'shift_rm]'w");
break;
}
case ib_x: {
if (instr->HasW() && (instr->Bits(6, 4) == 0x5)) {
uint32_t widthminus1 = static_cast<uint32_t>(instr->Bits(20, 16));
uint32_t lsbit = static_cast<uint32_t>(instr->Bits(11, 7));
uint32_t msbit = widthminus1 + lsbit;
if (msbit <= 31) {
if (instr->Bit(22)) {
Format(instr, "ubfx'cond 'rd, 'rm, 'f");
} else {
Format(instr, "sbfx'cond 'rd, 'rm, 'f");
}
} else {
UNREACHABLE();
}
} else if (!instr->HasW() && (instr->Bits(6, 4) == 0x1)) {
uint32_t lsbit = static_cast<uint32_t>(instr->Bits(11, 7));
uint32_t msbit = static_cast<uint32_t>(instr->Bits(20, 16));
if (msbit >= lsbit) {
if (instr->RmValue() == 15) {
Format(instr, "bfc'cond 'rd, 'f");
} else {
Format(instr, "bfi'cond 'rd, 'rm, 'f");
}
} else {
UNREACHABLE();
}
} else {
Format(instr, "'memop'cond'b 'rd, ['rn, +'shift_rm]'w");
}
break;
}
default: {
// The PU field is a 2-bit field.
UNREACHABLE();
break;
}
}
}
void Decoder::DecodeType4(Instruction* instr) {
if (instr->Bit(22) != 0) {
// Privileged mode currently not supported.
Unknown(instr);
} else {
if (instr->HasL()) {
Format(instr, "ldm'cond'pu 'rn'w, 'rlist");
} else {
Format(instr, "stm'cond'pu 'rn'w, 'rlist");
}
}
}
void Decoder::DecodeType5(Instruction* instr) {
Format(instr, "b'l'cond 'target");
}
void Decoder::DecodeType6(Instruction* instr) {
DecodeType6CoprocessorIns(instr);
}
int Decoder::DecodeType7(Instruction* instr) {
if (instr->Bit(24) == 1) {
if (instr->SvcValue() >= kStopCode) {
Format(instr, "stop'cond 'svc");
// Also print the stop message. Its address is encoded
// in the following 4 bytes.
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
"\n %p %08x stop message: %s",
reinterpret_cast<int32_t*>(instr
+ Instruction::kInstrSize),
*reinterpret_cast<char**>(instr
+ Instruction::kInstrSize),
*reinterpret_cast<char**>(instr
+ Instruction::kInstrSize));
// We have decoded 2 * Instruction::kInstrSize bytes.
return 2 * Instruction::kInstrSize;
} else {
Format(instr, "svc'cond 'svc");
}
} else {
DecodeTypeVFP(instr);
}
return Instruction::kInstrSize;
}
// void Decoder::DecodeTypeVFP(Instruction* instr)
// vmov: Sn = Rt
// vmov: Rt = Sn
// vcvt: Dd = Sm
// vcvt: Sd = Dm
// Dd = vabs(Dm)
// Dd = vneg(Dm)
// Dd = vadd(Dn, Dm)
// Dd = vsub(Dn, Dm)
// Dd = vmul(Dn, Dm)
// Dd = vdiv(Dn, Dm)
// vcmp(Dd, Dm)
// vmrs
// vmsr
// Dd = vsqrt(Dm)
void Decoder::DecodeTypeVFP(Instruction* instr) {
VERIFY((instr->TypeValue() == 7) && (instr->Bit(24) == 0x0) );
VERIFY(instr->Bits(11, 9) == 0x5);
if (instr->Bit(4) == 0) {
if (instr->Opc1Value() == 0x7) {
// Other data processing instructions
if ((instr->Opc2Value() == 0x0) && (instr->Opc3Value() == 0x1)) {
// vmov register to register.
if (instr->SzValue() == 0x1) {
Format(instr, "vmov.f64'cond 'Dd, 'Dm");
} else {
Format(instr, "vmov.f32'cond 'Sd, 'Sm");
}
} else if ((instr->Opc2Value() == 0x0) && (instr->Opc3Value() == 0x3)) {
// vabs
Format(instr, "vabs.f64'cond 'Dd, 'Dm");
} else if ((instr->Opc2Value() == 0x1) && (instr->Opc3Value() == 0x1)) {
// vneg
Format(instr, "vneg.f64'cond 'Dd, 'Dm");
} else if ((instr->Opc2Value() == 0x7) && (instr->Opc3Value() == 0x3)) {
DecodeVCVTBetweenDoubleAndSingle(instr);
} else if ((instr->Opc2Value() == 0x8) && (instr->Opc3Value() & 0x1)) {
DecodeVCVTBetweenFloatingPointAndInteger(instr);
} else if (((instr->Opc2Value() >> 1) == 0x6) &&
(instr->Opc3Value() & 0x1)) {
DecodeVCVTBetweenFloatingPointAndInteger(instr);
} else if (((instr->Opc2Value() == 0x4) || (instr->Opc2Value() == 0x5)) &&
(instr->Opc3Value() & 0x1)) {
DecodeVCMP(instr);
} else if (((instr->Opc2Value() == 0x1)) && (instr->Opc3Value() == 0x3)) {
Format(instr, "vsqrt.f64'cond 'Dd, 'Dm");
} else if (instr->Opc3Value() == 0x0) {
if (instr->SzValue() == 0x1) {
Format(instr, "vmov.f64'cond 'Dd, 'd");
} else {
Unknown(instr); // Not used by V8.
}
} else {
Unknown(instr); // Not used by V8.
}
} else if (instr->Opc1Value() == 0x3) {
if (instr->SzValue() == 0x1) {
if (instr->Opc3Value() & 0x1) {
Format(instr, "vsub.f64'cond 'Dd, 'Dn, 'Dm");
} else {
Format(instr, "vadd.f64'cond 'Dd, 'Dn, 'Dm");
}
} else {
Unknown(instr); // Not used by V8.
}
} else if ((instr->Opc1Value() == 0x2) && !(instr->Opc3Value() & 0x1)) {
if (instr->SzValue() == 0x1) {
Format(instr, "vmul.f64'cond 'Dd, 'Dn, 'Dm");
} else {
Unknown(instr); // Not used by V8.
}
} else if ((instr->Opc1Value() == 0x4) && !(instr->Opc3Value() & 0x1)) {
if (instr->SzValue() == 0x1) {
Format(instr, "vdiv.f64'cond 'Dd, 'Dn, 'Dm");
} else {
Unknown(instr); // Not used by V8.
}
} else {
Unknown(instr); // Not used by V8.
}
} else {
if ((instr->VCValue() == 0x0) &&
(instr->VAValue() == 0x0)) {
DecodeVMOVBetweenCoreAndSinglePrecisionRegisters(instr);
} else if ((instr->VCValue() == 0x0) &&
(instr->VAValue() == 0x7) &&
(instr->Bits(19, 16) == 0x1)) {
if (instr->VLValue() == 0) {
if (instr->Bits(15, 12) == 0xF) {
Format(instr, "vmsr'cond FPSCR, APSR");
} else {
Format(instr, "vmsr'cond FPSCR, 'rt");
}
} else {
if (instr->Bits(15, 12) == 0xF) {
Format(instr, "vmrs'cond APSR, FPSCR");
} else {
Format(instr, "vmrs'cond 'rt, FPSCR");
}
}
}
}
}
void Decoder::DecodeVMOVBetweenCoreAndSinglePrecisionRegisters(
Instruction* instr) {
VERIFY((instr->Bit(4) == 1) && (instr->VCValue() == 0x0) &&
(instr->VAValue() == 0x0));
bool to_arm_register = (instr->VLValue() == 0x1);
if (to_arm_register) {
Format(instr, "vmov'cond 'rt, 'Sn");
} else {
Format(instr, "vmov'cond 'Sn, 'rt");
}
}
void Decoder::DecodeVCMP(Instruction* instr) {
VERIFY((instr->Bit(4) == 0) && (instr->Opc1Value() == 0x7));
VERIFY(((instr->Opc2Value() == 0x4) || (instr->Opc2Value() == 0x5)) &&
(instr->Opc3Value() & 0x1));
// Comparison.
bool dp_operation = (instr->SzValue() == 1);
bool raise_exception_for_qnan = (instr->Bit(7) == 0x1);
if (dp_operation && !raise_exception_for_qnan) {
if (instr->Opc2Value() == 0x4) {
Format(instr, "vcmp.f64'cond 'Dd, 'Dm");
} else if (instr->Opc2Value() == 0x5) {
Format(instr, "vcmp.f64'cond 'Dd, #0.0");
} else {
Unknown(instr); // invalid
}
} else {
Unknown(instr); // Not used by V8.
}
}
void Decoder::DecodeVCVTBetweenDoubleAndSingle(Instruction* instr) {
VERIFY((instr->Bit(4) == 0) && (instr->Opc1Value() == 0x7));
VERIFY((instr->Opc2Value() == 0x7) && (instr->Opc3Value() == 0x3));
bool double_to_single = (instr->SzValue() == 1);
if (double_to_single) {
Format(instr, "vcvt.f32.f64'cond 'Sd, 'Dm");
} else {
Format(instr, "vcvt.f64.f32'cond 'Dd, 'Sm");
}
}
void Decoder::DecodeVCVTBetweenFloatingPointAndInteger(Instruction* instr) {
VERIFY((instr->Bit(4) == 0) && (instr->Opc1Value() == 0x7));
VERIFY(((instr->Opc2Value() == 0x8) && (instr->Opc3Value() & 0x1)) ||
(((instr->Opc2Value() >> 1) == 0x6) && (instr->Opc3Value() & 0x1)));
bool to_integer = (instr->Bit(18) == 1);
bool dp_operation = (instr->SzValue() == 1);
if (to_integer) {
bool unsigned_integer = (instr->Bit(16) == 0);
if (dp_operation) {
if (unsigned_integer) {
Format(instr, "vcvt.u32.f64'cond 'Sd, 'Dm");
} else {
Format(instr, "vcvt.s32.f64'cond 'Sd, 'Dm");
}
} else {
if (unsigned_integer) {
Format(instr, "vcvt.u32.f32'cond 'Sd, 'Sm");
} else {
Format(instr, "vcvt.s32.f32'cond 'Sd, 'Sm");
}
}
} else {
bool unsigned_integer = (instr->Bit(7) == 0);
if (dp_operation) {
if (unsigned_integer) {
Format(instr, "vcvt.f64.u32'cond 'Dd, 'Sm");
} else {
Format(instr, "vcvt.f64.s32'cond 'Dd, 'Sm");
}
} else {
if (unsigned_integer) {
Format(instr, "vcvt.f32.u32'cond 'Sd, 'Sm");
} else {
Format(instr, "vcvt.f32.s32'cond 'Sd, 'Sm");
}
}
}
}
// Decode Type 6 coprocessor instructions.
// Dm = vmov(Rt, Rt2)
// <Rt, Rt2> = vmov(Dm)
// Ddst = MEM(Rbase + 4*offset).
// MEM(Rbase + 4*offset) = Dsrc.
void Decoder::DecodeType6CoprocessorIns(Instruction* instr) {
VERIFY(instr->TypeValue() == 6);
if (instr->CoprocessorValue() == 0xA) {
switch (instr->OpcodeValue()) {
case 0x8:
case 0xA:
if (instr->HasL()) {
Format(instr, "vldr'cond 'Sd, ['rn - 4*'imm08@00]");
} else {
Format(instr, "vstr'cond 'Sd, ['rn - 4*'imm08@00]");
}
break;
case 0xC:
case 0xE:
if (instr->HasL()) {
Format(instr, "vldr'cond 'Sd, ['rn + 4*'imm08@00]");
} else {
Format(instr, "vstr'cond 'Sd, ['rn + 4*'imm08@00]");
}
break;
case 0x4:
case 0x5:
case 0x6:
case 0x7:
case 0x9:
case 0xB: {
bool to_vfp_register = (instr->VLValue() == 0x1);
if (to_vfp_register) {
Format(instr, "vldm'cond'pu 'rn'w, {'Sd-'Sd+}");
} else {
Format(instr, "vstm'cond'pu 'rn'w, {'Sd-'Sd+}");
}
break;
}
default:
Unknown(instr); // Not used by V8.
}
} else if (instr->CoprocessorValue() == 0xB) {
switch (instr->OpcodeValue()) {
case 0x2:
// Load and store double to two GP registers
if (instr->Bits(7, 4) != 0x1) {
Unknown(instr); // Not used by V8.
} else if (instr->HasL()) {
Format(instr, "vmov'cond 'rt, 'rn, 'Dm");
} else {
Format(instr, "vmov'cond 'Dm, 'rt, 'rn");
}
break;
case 0x8:
if (instr->HasL()) {
Format(instr, "vldr'cond 'Dd, ['rn - 4*'imm08@00]");
} else {
Format(instr, "vstr'cond 'Dd, ['rn - 4*'imm08@00]");
}
break;
case 0xC:
if (instr->HasL()) {
Format(instr, "vldr'cond 'Dd, ['rn + 4*'imm08@00]");
} else {
Format(instr, "vstr'cond 'Dd, ['rn + 4*'imm08@00]");
}
break;
case 0x4:
case 0x5:
case 0x9: {
bool to_vfp_register = (instr->VLValue() == 0x1);
if (to_vfp_register) {
Format(instr, "vldm'cond'pu 'rn'w, {'Dd-'Dd+}");
} else {
Format(instr, "vstm'cond'pu 'rn'w, {'Dd-'Dd+}");
}
break;
}
default:
Unknown(instr); // Not used by V8.
}
} else {
Unknown(instr); // Not used by V8.
}
}
#undef VERIFIY
bool Decoder::IsConstantPoolAt(byte* instr_ptr) {
int instruction_bits = *(reinterpret_cast<int*>(instr_ptr));
return (instruction_bits & kConstantPoolMarkerMask) == kConstantPoolMarker;
}
int Decoder::ConstantPoolSizeAt(byte* instr_ptr) {
if (IsConstantPoolAt(instr_ptr)) {
int instruction_bits = *(reinterpret_cast<int*>(instr_ptr));
return instruction_bits & kConstantPoolLengthMask;
} else {
return -1;
}
}
// Disassemble the instruction at *instr_ptr into the output buffer.
int Decoder::InstructionDecode(byte* instr_ptr) {
Instruction* instr = Instruction::At(instr_ptr);
// Print raw instruction bytes.
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
"%08x ",
instr->InstructionBits());
if (instr->ConditionField() == kSpecialCondition) {
Unknown(instr);
return Instruction::kInstrSize;
}
int instruction_bits = *(reinterpret_cast<int*>(instr_ptr));
if ((instruction_bits & kConstantPoolMarkerMask) == kConstantPoolMarker) {
out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
"constant pool begin (length %d)",
instruction_bits &
kConstantPoolLengthMask);
return Instruction::kInstrSize;
}
switch (instr->TypeValue()) {
case 0:
case 1: {
DecodeType01(instr);
break;
}
case 2: {
DecodeType2(instr);
break;
}
case 3: {
DecodeType3(instr);
break;
}
case 4: {
DecodeType4(instr);
break;
}
case 5: {
DecodeType5(instr);
break;
}
case 6: {
DecodeType6(instr);
break;
}
case 7: {
return DecodeType7(instr);
}
default: {
// The type field is 3-bits in the ARM encoding.
UNREACHABLE();
break;
}
}
return Instruction::kInstrSize;
}
} } // namespace v8::internal
//------------------------------------------------------------------------------
namespace disasm {
const char* NameConverter::NameOfAddress(byte* addr) const {
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 {
return v8::internal::Registers::Name(reg);
}
const char* NameConverter::NameOfByteCPURegister(int reg) const {
UNREACHABLE(); // ARM does not have the concept of a byte register
return "nobytereg";
}
const char* NameConverter::NameOfXMMRegister(int reg) const {
UNREACHABLE(); // ARM does not have any XMM registers
return "noxmmreg";
}
const char* NameConverter::NameInCode(byte* addr) const {
// The default name converter is called for unknown code. So we will not try
// to access any memory.
return "";
}
//------------------------------------------------------------------------------
Disassembler::Disassembler(const NameConverter& converter)
: converter_(converter) {}
Disassembler::~Disassembler() {}
int Disassembler::InstructionDecode(v8::internal::Vector<char> buffer,
byte* instruction) {
v8::internal::Decoder d(converter_, buffer);
return d.InstructionDecode(instruction);
}
int Disassembler::ConstantPoolSizeAt(byte* instruction) {
return v8::internal::Decoder::ConstantPoolSizeAt(instruction);
}
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 %08x %s\n",
prev_pc, *reinterpret_cast<int32_t*>(prev_pc), buffer.start());
}
}
} // namespace disasm
#endif // V8_TARGET_ARCH_ARM