/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "disassembler_arm.h"
#include <iostream>
#include "base/logging.h"
#include "base/stringprintf.h"
#include "thread.h"
namespace art {
namespace arm {
DisassemblerArm::DisassemblerArm() {
}
size_t DisassemblerArm::Dump(std::ostream& os, const uint8_t* begin) {
if ((reinterpret_cast<intptr_t>(begin) & 1) == 0) {
DumpArm(os, begin);
return 4;
} else {
// remove thumb specifier bits
begin = reinterpret_cast<const uint8_t*>(reinterpret_cast<uintptr_t>(begin) & ~1);
return DumpThumb16(os, begin);
}
}
void DisassemblerArm::Dump(std::ostream& os, const uint8_t* begin, const uint8_t* end) {
if ((reinterpret_cast<intptr_t>(begin) & 1) == 0) {
for (const uint8_t* cur = begin; cur < end; cur += 4) {
DumpArm(os, cur);
}
} else {
// remove thumb specifier bits
begin = reinterpret_cast<const uint8_t*>(reinterpret_cast<uintptr_t>(begin) & ~1);
end = reinterpret_cast<const uint8_t*>(reinterpret_cast<uintptr_t>(end) & ~1);
for (const uint8_t* cur = begin; cur < end;) {
cur += DumpThumb16(os, cur);
}
}
}
static const char* kConditionCodeNames[] = {
"eq", // 0000 - equal
"ne", // 0001 - not-equal
"cs", // 0010 - carry-set, greater than, equal or unordered
"cc", // 0011 - carry-clear, less than
"mi", // 0100 - minus, negative
"pl", // 0101 - plus, positive or zero
"vs", // 0110 - overflow
"vc", // 0111 - no overflow
"hi", // 1000 - unsigned higher
"ls", // 1001 - unsigned lower or same
"ge", // 1010 - signed greater than or equal
"lt", // 1011 - signed less than
"gt", // 1100 - signed greater than
"le", // 1101 - signed less than or equal
"", // 1110 - always
"nv", // 1111 - never (mostly obsolete, but might be a clue that we're mistranslating)
};
void DisassemblerArm::DumpCond(std::ostream& os, uint32_t cond) {
if (cond < 15) {
os << kConditionCodeNames[cond];
} else {
os << "Unexpected condition: " << cond;
}
}
void DisassemblerArm::DumpBranchTarget(std::ostream& os, const uint8_t* instr_ptr, int32_t imm32) {
os << StringPrintf("%+d (%p)", imm32, instr_ptr + imm32);
}
static uint32_t ReadU16(const uint8_t* ptr) {
return ptr[0] | (ptr[1] << 8);
}
static uint32_t ReadU32(const uint8_t* ptr) {
return ptr[0] | (ptr[1] << 8) | (ptr[2] << 16) | (ptr[3] << 24);
}
static const char* kDataProcessingOperations[] = {
"and", "eor", "sub", "rsb", "add", "adc", "sbc", "rsc",
"tst", "teq", "cmp", "cmn", "orr", "mov", "bic", "mvn",
};
static const char* kThumbDataProcessingOperations[] = {
"and", "eor", "lsl", "lsr", "asr", "adc", "sbc", "ror",
"tst", "rsb", "cmp", "cmn", "orr", "mul", "bic", "mvn",
};
struct ArmRegister {
explicit ArmRegister(uint32_t r) : r(r) { CHECK_LE(r, 15U); }
ArmRegister(uint32_t instruction, uint32_t at_bit) : r((instruction >> at_bit) & 0xf) { CHECK_LE(r, 15U); }
uint32_t r;
};
std::ostream& operator<<(std::ostream& os, const ArmRegister& r) {
if (r.r == 13) {
os << "sp";
} else if (r.r == 14) {
os << "lr";
} else if (r.r == 15) {
os << "pc";
} else {
os << "r" << r.r;
}
return os;
}
struct ThumbRegister : ArmRegister {
ThumbRegister(uint16_t instruction, uint16_t at_bit) : ArmRegister((instruction >> at_bit) & 0x7) {}
};
struct Rm {
explicit Rm(uint32_t instruction) : shift((instruction >> 4) & 0xff), rm(instruction & 0xf) {}
uint32_t shift;
ArmRegister rm;
};
std::ostream& operator<<(std::ostream& os, const Rm& r) {
os << r.rm;
if (r.shift != 0) {
os << "-shift-" << r.shift; // TODO
}
return os;
}
struct ShiftedImmediate {
explicit ShiftedImmediate(uint32_t instruction) {
uint32_t rotate = ((instruction >> 8) & 0xf);
uint32_t imm = (instruction & 0xff);
value = (imm >> (2 * rotate)) | (imm << (32 - (2 * rotate)));
}
uint32_t value;
};
std::ostream& operator<<(std::ostream& os, const ShiftedImmediate& rhs) {
os << "#" << rhs.value;
return os;
}
struct RegisterList {
explicit RegisterList(uint32_t instruction) : register_list(instruction & 0xffff) {}
uint32_t register_list;
};
std::ostream& operator<<(std::ostream& os, const RegisterList& rhs) {
if (rhs.register_list == 0) {
os << "<no register list?>";
return os;
}
os << "{";
bool first = true;
for (size_t i = 0; i < 16; i++) {
if ((rhs.register_list & (1 << i)) != 0) {
if (first) {
first = false;
} else {
os << ", ";
}
os << ArmRegister(i);
}
}
os << "}";
return os;
}
void DisassemblerArm::DumpArm(std::ostream& os, const uint8_t* instr_ptr) {
uint32_t instruction = ReadU32(instr_ptr);
uint32_t cond = (instruction >> 28) & 0xf;
uint32_t op1 = (instruction >> 25) & 0x7;
std::string opcode;
std::string suffixes;
std::ostringstream args;
switch (op1) {
case 0:
case 1: // Data processing instructions.
{
if ((instruction & 0x0ff000f0) == 0x01200070) { // BKPT
opcode = "bkpt";
uint32_t imm12 = (instruction >> 8) & 0xfff;
uint32_t imm4 = (instruction & 0xf);
args << '#' << ((imm12 << 4) | imm4);
break;
}
if ((instruction & 0x0fffffd0) == 0x012fff10) { // BX and BLX (register)
opcode = (((instruction >> 5) & 1) ? "blx" : "bx");
args << ArmRegister(instruction & 0xf);
break;
}
bool i = (instruction & (1 << 25)) != 0;
bool s = (instruction & (1 << 20)) != 0;
uint32_t op = (instruction >> 21) & 0xf;
opcode = kDataProcessingOperations[op];
bool implicit_s = ((op & ~3) == 8); // TST, TEQ, CMP, and CMN.
if (implicit_s) {
// Rd is unused (and not shown), and we don't show the 's' suffix either.
} else {
if (s) {
suffixes += 's';
}
args << ArmRegister(instruction, 12) << ", ";
}
if (i) {
args << ArmRegister(instruction, 16) << ", " << ShiftedImmediate(instruction);
} else {
args << Rm(instruction);
}
}
break;
case 2: // Load/store word and unsigned byte.
{
bool p = (instruction & (1 << 24)) != 0;
bool b = (instruction & (1 << 22)) != 0;
bool w = (instruction & (1 << 21)) != 0;
bool l = (instruction & (1 << 20)) != 0;
opcode = StringPrintf("%s%s", (l ? "ldr" : "str"), (b ? "b" : ""));
args << ArmRegister(instruction, 12) << ", ";
ArmRegister rn(instruction, 16);
if (rn.r == 0xf) {
UNIMPLEMENTED(FATAL) << "literals";
} else {
bool wback = !p || w;
uint32_t offset = (instruction & 0xfff);
if (p && !wback) {
args << "[" << rn << ", #" << offset << "]";
} else if (p && wback) {
args << "[" << rn << ", #" << offset << "]!";
} else if (!p && wback) {
args << "[" << rn << "], #" << offset;
} else {
LOG(FATAL) << p << " " << w;
}
if (rn.r == 9) {
args << " ; ";
Thread::DumpThreadOffset(args, offset, 4);
}
}
}
break;
case 4: // Load/store multiple.
{
bool p = (instruction & (1 << 24)) != 0;
bool u = (instruction & (1 << 23)) != 0;
bool w = (instruction & (1 << 21)) != 0;
bool l = (instruction & (1 << 20)) != 0;
opcode = StringPrintf("%s%c%c", (l ? "ldm" : "stm"), (u ? 'i' : 'd'), (p ? 'b' : 'a'));
args << ArmRegister(instruction, 16) << (w ? "!" : "") << ", " << RegisterList(instruction);
}
break;
case 5: // Branch/branch with link.
{
bool bl = (instruction & (1 << 24)) != 0;
opcode = (bl ? "bl" : "b");
int32_t imm26 = (instruction & 0xffffff) << 2;
int32_t imm32 = (imm26 << 6) >> 6; // Sign extend.
DumpBranchTarget(args, instr_ptr + 8, imm32);
}
break;
default:
opcode = "???";
break;
}
opcode += kConditionCodeNames[cond];
opcode += suffixes;
// TODO: a more complete ARM disassembler could generate wider opcodes.
os << StringPrintf("%p: %08x\t%-7s ", instr_ptr, instruction, opcode.c_str()) << args.str() << '\n';
}
size_t DisassemblerArm::DumpThumb32(std::ostream& os, const uint8_t* instr_ptr) {
uint32_t instr = (ReadU16(instr_ptr) << 16) | ReadU16(instr_ptr + 2);
// |111|1 1|1000000|0000|1111110000000000|
// |5 3|2 1|0987654|3 0|5 0 5 0|
// |---|---|-------|----|----------------|
// |332|2 2|2222222|1111|1111110000000000|
// |1 9|8 7|6543210|9 6|5 0 5 0|
// |---|---|-------|----|----------------|
// |111|op1| op2 | | |
uint32_t op1 = (instr >> 27) & 3;
if (op1 == 0) {
return DumpThumb16(os, instr_ptr);
}
uint32_t op2 = (instr >> 20) & 0x7F;
std::ostringstream opcode;
std::ostringstream args;
switch (op1) {
case 0:
break;
case 1:
if ((op2 & 0x64) == 0) { // 00x x0xx
// |111|11|10|00|0|00|0000|1111110000000000|
// |5 3|21|09|87|6|54|3 0|5 0 5 0|
// |---|--|--|--|-|--|----|----------------|
// |332|22|22|22|2|22|1111|1111110000000000|
// |1 9|87|65|43|2|10|9 6|5 0 5 0|
// |---|--|--|--|-|--|----|----------------|
// |111|01|00|op|0|WL| Rn | |
// |111|01| op2 | | |
// STM - 111 01 00-01-0-W0 nnnn rrrrrrrrrrrrrrrr
// LDM - 111 01 00-01-0-W1 nnnn rrrrrrrrrrrrrrrr
// PUSH- 111 01 00-01-0-10 1101 0M0rrrrrrrrrrrrr
// POP - 111 01 00-01-0-11 1101 PM0rrrrrrrrrrrrr
uint32_t op = (instr >> 23) & 3;
uint32_t W = (instr >> 21) & 1;
uint32_t L = (instr >> 20) & 1;
ArmRegister Rn(instr, 16);
if (op == 1 || op == 2) {
if (op == 1) {
if (L == 0) {
opcode << "stm";
args << Rn << (W == 0 ? "" : "!") << ", ";
} else {
if (Rn.r != 13) {
opcode << "ldm";
args << Rn << (W == 0 ? "" : "!") << ", ";
} else {
opcode << "pop";
}
}
} else {
if (L == 0) {
if (Rn.r != 13) {
opcode << "stmdb";
args << Rn << (W == 0 ? "" : "!") << ", ";
} else {
opcode << "push";
}
} else {
opcode << "ldmdb";
args << Rn << (W == 0 ? "" : "!") << ", ";
}
}
args << RegisterList(instr);
}
} else if ((op2 & 0x64) == 4) { // 00x x1xx
uint32_t op3 = (instr >> 23) & 3;
uint32_t op4 = (instr >> 20) & 3;
// uint32_t op5 = (instr >> 4) & 0xF;
ArmRegister Rn(instr, 16);
ArmRegister Rt(instr, 12);
uint32_t imm8 = instr & 0xFF;
if (op3 == 0 && op4 == 0) { // STREX
ArmRegister Rd(instr, 8);
opcode << "strex";
args << Rd << ", " << Rt << ", [" << Rn << ", #" << (imm8 << 2) << "]";
} else if (op3 == 0 && op4 == 1) { // LDREX
opcode << "ldrex";
args << Rt << ", [" << Rn << ", #" << (imm8 << 2) << "]";
}
} else if ((op2 & 0x60) == 0x20) { // 01x xxxx
// Data-processing (shifted register)
// |111|1110|0000|0|0000|1111|1100|00|00|0000|
// |5 3|2109|8765|4|3 0|5 |10 8|7 |5 |3 0|
// |---|----|----|-|----|----|----|--|--|----|
// |332|2222|2222|2|1111|1111|1100|00|00|0000|
// |1 9|8765|4321|0|9 6|5 |10 8|7 |5 |3 0|
// |---|----|----|-|----|----|----|--|--|----|
// |111|0101| op3|S| Rn |imm3| Rd |i2|ty| Rm |
uint32_t op3 = (instr >> 21) & 0xF;
uint32_t S = (instr >> 20) & 1;
uint32_t imm3 = ((instr >> 12) & 0x7);
uint32_t imm2 = ((instr >> 6) & 0x3);
uint32_t imm5 = ((imm3 << 3) | imm2) & 0x1F;
uint32_t shift_type = ((instr >> 4) & 0x2);
ArmRegister Rd(instr, 8);
ArmRegister Rn(instr, 16);
ArmRegister Rm(instr, 0);
switch (op3) {
case 0x0:
if (Rd.r != 0xF) {
opcode << "and";
} else {
if (S != 1U) {
opcode << "UNKNOWN TST-" << S;
break;
}
opcode << "tst";
S = 0; // don't print 's'
}
break;
case 0x1: opcode << "bic"; break;
case 0x2:
if (Rn.r != 0xF) {
opcode << "orr";
} else {
// TODO: use canonical form if there is a shift (lsl, ...).
opcode << "mov";
}
break;
case 0x3:
if (Rn.r != 0xF) {
opcode << "orn";
} else {
opcode << "mvn";
}
break;
case 0x4:
if (Rd.r != 0xF) {
opcode << "eor";
} else {
if (S != 1U) {
opcode << "UNKNOWN TEQ-" << S;
break;
}
opcode << "teq";
S = 0; // don't print 's'
}
break;
case 0x6: opcode << "pkh"; break;
case 0x8:
if (Rd.r != 0xF) {
opcode << "add";
} else {
if (S != 1U) {
opcode << "UNKNOWN CMN-" << S;
break;
}
opcode << "cmn";
S = 0; // don't print 's'
}
break;
case 0xA: opcode << "adc"; break;
case 0xB: opcode << "sbc"; break;
case 0xD:
if (Rd.r != 0xF) {
opcode << "sub";
} else {
if (S != 1U) {
opcode << "UNKNOWN CMP-" << S;
break;
}
opcode << "cmp";
S = 0; // don't print 's'
}
break;
case 0xE: opcode << "rsb"; break;
default: opcode << "UNKNOWN DPSR-" << op3; break;
}
if (S == 1) {
opcode << "s";
}
opcode << ".w";
if (Rd.r != 0xF) {
args << Rd << ", ";
}
if (Rn.r != 0xF) {
args << Rn << ", ";
}
args << Rm;
// Shift operand.
bool noShift = (imm5 == 0 && shift_type != 0x3);
if (!noShift) {
args << ", ";
switch (shift_type) {
case 0x0: args << "lsl"; break;
case 0x1: args << "lsr"; break;
case 0x2: args << "asr"; break;
case 0x3:
if (imm5 == 0) {
args << "rrx";
} else {
args << "ror";
}
break;
}
if (shift_type != 0x3 /* rrx */) {
args << StringPrintf(" #%d", imm5);
}
}
} else if ((op2 & 0x40) == 0x40) { // 1xx xxxx
// Co-processor instructions
// |111|1|11|000000|0000|1111|1100|000|0 |0000|
// |5 3|2|10|987654|3 0|54 2|10 8|7 5|4 | 0|
// |---|-|--|------|----|----|----|---|---|----|
// |332|2|22|222222|1111|1111|1100|000|0 |0000|
// |1 9|8|76|543210|9 6|54 2|10 8|7 5|4 | 0|
// |---|-|--|------|----|----|----|---|---|----|
// |111| |11| op3 | Rn | |copr| |op4| |
uint32_t op3 = (instr >> 20) & 0x3F;
uint32_t coproc = (instr >> 8) & 0xF;
uint32_t op4 = (instr >> 4) & 0x1;
if ((op3 == 2 || op3 == 2 || op3 == 6 || op3 == 7) || // 00x1x
(op3 >= 8 && op3 <= 15) || (op3 >= 16 && op3 <= 31)) { // 001xxx, 01xxxx
// Extension register load/store instructions
// |111|1|110|00000|0000|1111|110|000000000|
// |5 3|2|109|87654|3 0|54 2|10 |87 54 0|
// |---|-|---|-----|----|----|---|---------|
// |332|2|222|22222|1111|1111|110|000000000|
// |1 9|8|765|43210|9 6|54 2|10 |87 54 0|
// |---|-|---|-----|----|----|---|---------|
// |111|T|110| op3 | Rn | |101| |
// 111 0 110 01001 0011 0000 101 000000011 - ec930a03
if (op3 == 9 || op3 == 0xD) { // VLDM
// 1110 110 PUDW1 nnnn dddd 101S iiii iiii
uint32_t P = (instr >> 24) & 1;
uint32_t U = (instr >> 23) & 1;
uint32_t D = (instr >> 22) & 1;
uint32_t W = (instr >> 21) & 1;
uint32_t S = (instr >> 8) & 1;
ArmRegister Rn(instr, 16);
uint32_t Vd = (instr >> 12) & 0xF;
uint32_t imm8 = instr & 0xFF;
uint32_t d = (S == 0 ? ((Vd << 1) | D) : (Vd | (D << 4)));
if (P == 0 && U == 0 && W == 0) {
// TODO: 64bit transfers between ARM core and extension registers.
} else if (P == 0 && U == 1 && Rn.r == 13) { // VPOP
opcode << "vpop" << (S == 0 ? ".f64" : ".f32");
args << d << " .. " << (d + imm8);
} else if (P == 1 && W == 0) { // VLDR
opcode << "vldr" << (S == 0 ? ".f64" : ".f32");
args << d << ", [" << Rn << ", #" << imm8 << "]";
} else { // VLDM
opcode << "vldm" << (S == 0 ? ".f64" : ".f32");
args << Rn << ", " << d << " .. " << (d + imm8);
}
}
} else if ((op3 & 0x30) == 0x20 && op4 == 0) { // 10 xxxx ... 0
if ((coproc & 0xE) == 0xA) {
// VFP data-processing instructions
// |111|1|1100|0000|0000|1111|110|0|00 |0|0|0000|
// |5 3|2|1098|7654|3 0|54 2|10 |8|76 |5|4|3 0|
// |---|-|----|----|----|----|---|-|----|-|-|----|
// |332|2|2222|2222|1111|1111|110|0|00 |0|0|0000|
// |1 9|8|7654|3210|9 6|54 2|109|8|76 |5|4|3 0|
// |---|-|----|----|----|----|---|-|----|-|-|----|
// |111|T|1110|opc1|opc2| |101| |opc3| | | |
// 111 0 1110|1111 0100 1110 101 0 01 1 0 1001 - eef4ea69
uint32_t opc1 = (instr >> 20) & 0xF;
uint32_t opc2 = (instr >> 16) & 0xF;
uint32_t opc3 = (instr >> 6) & 0x3;
if ((opc1 & 0xB) == 0xB) { // 1x11
// Other VFP data-processing instructions.
uint32_t D = (instr >> 22) & 0x1;
uint32_t Vd = (instr >> 12) & 0xF;
uint32_t sz = (instr >> 8) & 1;
uint32_t M = (instr >> 5) & 1;
uint32_t Vm = instr & 0xF;
bool dp_operation = sz == 1;
switch (opc2) {
case 0x1: // Vneg/Vsqrt
// 1110 11101 D 11 0001 dddd 101s o1M0 mmmm
opcode << (opc3 == 1 ? "vneg" : "vsqrt") << (dp_operation ? ".f64" : ".f32");
if (dp_operation) {
args << "f" << ((D << 4) | Vd) << ", " << "f" << ((M << 4) | Vm);
} else {
args << "f" << ((Vd << 1) | D) << ", " << "f" << ((Vm << 1) | M);
}
break;
case 0x4: case 0x5: { // Vector compare
// 1110 11101 D 11 0100 dddd 101 sE1M0 mmmm
opcode << (opc3 == 1 ? "vcmp" : "vcmpe") << (dp_operation ? ".f64" : ".f32");
if (dp_operation) {
args << "f" << ((D << 4) | Vd) << ", " << "f" << ((M << 4) | Vm);
} else {
args << "f" << ((Vd << 1) | D) << ", " << "f" << ((Vm << 1) | M);
}
break;
}
}
}
}
} else if ((op3 & 0x30) == 0x30) { // 11 xxxx
// Advanced SIMD
if ((instr & 0xFFBF0ED0) == 0xeeb10ac0) { // Vsqrt
// 1110 11101 D 11 0001 dddd 101S 11M0 mmmm
// 1110 11101 0 11 0001 1101 1011 1100 1000 - eeb1dbc8
uint32_t D = (instr >> 22) & 1;
uint32_t Vd = (instr >> 12) & 0xF;
uint32_t sz = (instr >> 8) & 1;
uint32_t M = (instr >> 5) & 1;
uint32_t Vm = instr & 0xF;
bool dp_operation = sz == 1;
opcode << "vsqrt" << (dp_operation ? ".f64" : ".f32");
if (dp_operation) {
args << "f" << ((D << 4) | Vd) << ", " << "f" << ((M << 4) | Vm);
} else {
args << "f" << ((Vd << 1) | D) << ", " << "f" << ((Vm << 1) | M);
}
}
}
}
break;
case 2:
if ((instr & 0x8000) == 0 && (op2 & 0x20) == 0) {
// Data-processing (modified immediate)
// |111|11|10|0000|0|0000|1|111|1100|00000000|
// |5 3|21|09|8765|4|3 0|5|4 2|10 8|7 5 0|
// |---|--|--|----|-|----|-|---|----|--------|
// |332|22|22|2222|2|1111|1|111|1100|00000000|
// |1 9|87|65|4321|0|9 6|5|4 2|10 8|7 5 0|
// |---|--|--|----|-|----|-|---|----|--------|
// |111|10|i0| op3|S| Rn |0|iii| Rd |iiiiiiii|
// 111 10 x0 xxxx x xxxx opxxx xxxx xxxxxxxx
uint32_t i = (instr >> 26) & 1;
uint32_t op3 = (instr >> 21) & 0xF;
uint32_t S = (instr >> 20) & 1;
ArmRegister Rn(instr, 16);
uint32_t imm3 = (instr >> 12) & 7;
ArmRegister Rd(instr, 8);
uint32_t imm8 = instr & 0xFF;
int32_t imm32 = (i << 11) | (imm3 << 8) | imm8;
if (Rn.r == 0xF && (op3 == 0x2 || op3 == 0x3)) {
if (op3 == 0x2) {
opcode << "mov";
if (S == 1) {
opcode << "s";
}
opcode << ".w";
} else {
opcode << "mvn";
if (S == 1) {
opcode << "s";
}
}
args << Rd << ", ThumbExpand(" << imm32 << ")";
} else if (Rd.r == 0xF && S == 1 &&
(op3 == 0x0 || op3 == 0x4 || op3 == 0x8 || op3 == 0xD)) {
if (op3 == 0x0) {
opcode << "tst";
} else if (op3 == 0x4) {
opcode << "teq";
} else if (op3 == 0x8) {
opcode << "cmw";
} else {
opcode << "cmp.w";
}
args << Rn << ", ThumbExpand(" << imm32 << ")";
} else {
switch (op3) {
case 0x0: opcode << "and"; break;
case 0x1: opcode << "bic"; break;
case 0x2: opcode << "orr"; break;
case 0x3: opcode << "orn"; break;
case 0x4: opcode << "eor"; break;
case 0x8: opcode << "add"; break;
case 0xA: opcode << "adc"; break;
case 0xB: opcode << "sbc"; break;
case 0xD: opcode << "sub"; break;
case 0xE: opcode << "rsb"; break;
default: opcode << "UNKNOWN DPMI-" << op3; break;
}
if (S == 1) {
opcode << "s";
}
args << Rd << ", " << Rn << ", ThumbExpand(" << imm32 << ")";
}
} else if ((instr & 0x8000) == 0 && (op2 & 0x20) != 0) {
// Data-processing (plain binary immediate)
// |111|11|10|00000|0000|1|111110000000000|
// |5 3|21|09|87654|3 0|5|4 0 5 0|
// |---|--|--|-----|----|-|---------------|
// |332|22|22|22222|1111|1|111110000000000|
// |1 9|87|65|43210|9 6|5|4 0 5 0|
// |---|--|--|-----|----|-|---------------|
// |111|10|x1| op3 | Rn |0|xxxxxxxxxxxxxxx|
uint32_t op3 = (instr >> 20) & 0x1F;
switch (op3) {
case 0x00: case 0x0A: {
// ADD/SUB.W Rd, Rn #imm12 - 111 10 i1 0101 0 nnnn 0 iii dddd iiiiiiii
ArmRegister Rd(instr, 8);
ArmRegister Rn(instr, 16);
uint32_t i = (instr >> 26) & 1;
uint32_t imm3 = (instr >> 12) & 0x7;
uint32_t imm8 = instr & 0xFF;
uint32_t imm12 = (i << 11) | (imm3 << 8) | imm8;
if (Rn.r != 0xF) {
opcode << (op3 == 0 ? "addw" : "subw");
args << Rd << ", " << Rn << ", #" << imm12;
} else {
opcode << "adr";
args << Rd << ", ";
DumpBranchTarget(args, instr_ptr + 4, (op3 == 0) ? imm12 : -imm12);
}
break;
}
case 0x04: case 0x0C: {
// MOVW/T Rd, #imm16 - 111 10 i0 0010 0 iiii 0 iii dddd iiiiiiii
ArmRegister Rd(instr, 8);
uint32_t i = (instr >> 26) & 1;
uint32_t imm3 = (instr >> 12) & 0x7;
uint32_t imm8 = instr & 0xFF;
uint32_t Rn = (instr >> 16) & 0xF;
uint32_t imm16 = (Rn << 12) | (i << 11) | (imm3 << 8) | imm8;
opcode << (op3 == 0x04 ? "movw" : "movt");
args << Rd << ", #" << imm16;
break;
}
case 0x16: {
// BFI Rd, Rn, #lsb, #width - 111 10 0 11 011 0 nnnn 0 iii dddd ii 0 iiiii
ArmRegister Rd(instr, 8);
ArmRegister Rn(instr, 16);
uint32_t msb = instr & 0x1F;
uint32_t imm2 = (instr >> 6) & 0x3;
uint32_t imm3 = (instr >> 12) & 0x7;
uint32_t lsb = (imm3 << 2) | imm2;
uint32_t width = msb - lsb + 1;
if (Rn.r != 0xF) {
opcode << "bfi";
args << Rd << ", " << Rn << ", #" << lsb << ", #" << width;
} else {
opcode << "bfc";
args << Rd << ", #" << lsb << ", #" << width;
}
break;
}
default:
break;
}
} else {
// Branches and miscellaneous control
// |111|11|1000000|0000|1|111|1100|00000000|
// |5 3|21|0987654|3 0|5|4 2|10 8|7 5 0|
// |---|--|-------|----|-|---|----|--------|
// |332|22|2222222|1111|1|111|1100|00000000|
// |1 9|87|6543210|9 6|5|4 2|10 8|7 5 0|
// |---|--|-------|----|-|---|----|--------|
// |111|10| op2 | |1|op3|op4 | |
uint32_t op3 = (instr >> 12) & 7;
// uint32_t op4 = (instr >> 8) & 0xF;
switch (op3) {
case 0:
if ((op2 & 0x38) != 0x38) {
// Conditional branch
// |111|11|1|0000|000000|1|1|1 |1|1 |10000000000|
// |5 3|21|0|9876|543 0|5|4|3 |2|1 |0 5 0|
// |---|--|-|----|------|-|-|--|-|--|-----------|
// |332|22|2|2222|221111|1|1|1 |1|1 |10000000000|
// |1 9|87|6|5432|109 6|5|4|3 |2|1 |0 5 0|
// |---|--|-|----|------|-|-|--|-|--|-----------|
// |111|10|S|cond| imm6 |1|0|J1|0|J2| imm11 |
uint32_t S = (instr >> 26) & 1;
uint32_t J2 = (instr >> 11) & 1;
uint32_t J1 = (instr >> 13) & 1;
uint32_t imm6 = (instr >> 16) & 0x3F;
uint32_t imm11 = instr & 0x7FF;
uint32_t cond = (instr >> 22) & 0xF;
int32_t imm32 = (S << 20) | (J2 << 19) | (J1 << 18) | (imm6 << 12) | (imm11 << 1);
imm32 = (imm32 << 11) >> 11; // sign extend 21bit immediate
opcode << "b";
DumpCond(opcode, cond);
opcode << ".w";
DumpBranchTarget(args, instr_ptr + 4, imm32);
} else if (op2 == 0x3B) {
// Miscellaneous control instructions
uint32_t op5 = (instr >> 4) & 0xF;
switch (op5) {
case 4: opcode << "dsb"; break;
case 5: opcode << "dmb"; break;
case 6: opcode << "isb"; break;
}
}
break;
case 2:
if ((op2 & 0x38) == 0x38) {
if (op2 == 0x7F) {
opcode << "udf";
}
break;
}
// Else deliberate fall-through to B.
case 1: case 3: {
// B
// |111|11|1|0000|000000|11|1 |1|1 |10000000000|
// |5 3|21|0|9876|543 0|54|3 |2|1 |0 5 0|
// |---|--|-|----|------|--|--|-|--|-----------|
// |332|22|2|2222|221111|11|1 |1|1 |10000000000|
// |1 9|87|6|5 2|10 6|54|3 |2|1 |0 5 0|
// |---|--|-|----|------|--|--|-|--|-----------|
// |111|10|S|cond| imm6 |10|J1|0|J2| imm11 |
// |111|10|S| imm10 |10|J1|1|J2| imm11 |
uint32_t S = (instr >> 26) & 1;
uint32_t cond = (instr >> 22) & 0xF;
uint32_t J2 = (instr >> 11) & 1;
uint32_t form = (instr >> 12) & 1;
uint32_t J1 = (instr >> 13) & 1;
uint32_t imm10 = (instr >> 16) & 0x3FF;
uint32_t imm6 = (instr >> 16) & 0x3F;
uint32_t imm11 = instr & 0x7FF;
opcode << "b";
int32_t imm32;
if (form == 0) {
DumpCond(opcode, cond);
imm32 = (S << 20) | (J2 << 19) | (J1 << 18) | (imm6 << 12) | (imm11 << 1);
imm32 = (imm32 << 11) >> 11; // sign extend 21 bit immediate.
} else {
uint32_t I1 = ~(J1 ^ S);
uint32_t I2 = ~(J2 ^ S);
imm32 = (S << 24) | (I1 << 23) | (I2 << 22) | (imm10 << 12) | (imm11 << 1);
imm32 = (imm32 << 8) >> 8; // sign extend 24 bit immediate.
}
opcode << ".w";
DumpBranchTarget(args, instr_ptr + 4, imm32);
break;
}
case 4: case 6: case 5: case 7: {
// BL, BLX (immediate)
// |111|11|1|0000000000|11|1 |1|1 |10000000000|
// |5 3|21|0|9876543 0|54|3 |2|1 |0 5 0|
// |---|--|-|----------|--|--|-|--|-----------|
// |332|22|2|2222221111|11|1 |1|1 |10000000000|
// |1 9|87|6|5 0 6|54|3 |2|1 |0 5 0|
// |---|--|-|----------|--|--|-|--|-----------|
// |111|10|S| imm10 |11|J1|L|J2| imm11 |
uint32_t S = (instr >> 26) & 1;
uint32_t J2 = (instr >> 11) & 1;
uint32_t L = (instr >> 12) & 1;
uint32_t J1 = (instr >> 13) & 1;
uint32_t imm10 = (instr >> 16) & 0x3FF;
uint32_t imm11 = instr & 0x7FF;
if (L == 0) {
opcode << "bx";
} else {
opcode << "blx";
}
uint32_t I1 = ~(J1 ^ S);
uint32_t I2 = ~(J2 ^ S);
int32_t imm32 = (S << 24) | (I1 << 23) | (I2 << 22) | (imm10 << 12) | (imm11 << 1);
imm32 = (imm32 << 8) >> 8; // sign extend 24 bit immediate.
DumpBranchTarget(args, instr_ptr + 4, imm32);
break;
}
}
}
break;
case 3:
switch (op2) {
case 0x00: case 0x02: case 0x04: case 0x06: // 000xxx0
case 0x08: case 0x0A: case 0x0C: case 0x0E: {
// Store single data item
// |111|11|100|000|0|0000|1111|110000|000000|
// |5 3|21|098|765|4|3 0|5 2|10 6|5 0|
// |---|--|---|---|-|----|----|------|------|
// |332|22|222|222|2|1111|1111|110000|000000|
// |1 9|87|654|321|0|9 6|5 2|10 6|5 0|
// |---|--|---|---|-|----|----|------|------|
// |111|11|000|op3|0| | | op4 | |
uint32_t op3 = (instr >> 21) & 7;
// uint32_t op4 = (instr >> 6) & 0x3F;
switch (op3) {
case 0x0: case 0x4: {
// STRB Rt,[Rn,#+/-imm8] - 111 11 00 0 0 00 0 nnnn tttt 1 PUWii ii iiii
// STRB Rt,[Rn,Rm,lsl #imm2] - 111 11 00 0 0 00 0 nnnn tttt 0 00000 ii mmmm
ArmRegister Rn(instr, 16);
ArmRegister Rt(instr, 12);
opcode << "strb";
if ((instr & 0x800) != 0) {
uint32_t imm8 = instr & 0xFF;
args << Rt << ", [" << Rn << ",#" << imm8 << "]";
} else {
uint32_t imm2 = (instr >> 4) & 3;
ArmRegister Rm(instr, 0);
args << Rt << ", [" << Rn << ", " << Rm;
if (imm2 != 0) {
args << ", " << "lsl #" << imm2;
}
args << "]";
}
break;
}
case 0x2: case 0x6: {
ArmRegister Rn(instr, 16);
ArmRegister Rt(instr, 12);
if (op3 == 2) {
if ((instr & 0x800) != 0) {
// STR Rt, [Rn, #imm8] - 111 11 000 010 0 nnnn tttt 1PUWiiiiiiii
uint32_t P = (instr >> 10) & 1;
uint32_t U = (instr >> 9) & 1;
uint32_t W = (instr >> 8) & 1;
uint32_t imm8 = instr & 0xFF;
int32_t imm32 = (imm8 << 24) >> 24; // sign-extend imm8
if (Rn.r == 13 && P == 1 && U == 0 && W == 1 && imm32 == 4) {
opcode << "push";
args << Rt;
} else if (Rn.r == 15 || (P == 0 && W == 0)) {
opcode << "UNDEFINED";
} else {
if (P == 1 && U == 1 && W == 0) {
opcode << "strt";
} else {
opcode << "str";
}
args << Rt << ", [" << Rn;
if (P == 0 && W == 1) {
args << "], #" << imm32;
} else {
args << ", #" << imm32 << "]";
if (W == 1) {
args << "!";
}
}
}
} else {
// STR Rt, [Rn, Rm, LSL #imm2] - 111 11 000 010 0 nnnn tttt 000000iimmmm
ArmRegister Rn(instr, 16);
ArmRegister Rt(instr, 12);
ArmRegister Rm(instr, 0);
uint32_t imm2 = (instr >> 4) & 3;
opcode << "str.w";
args << Rt << ", [" << Rn << ", " << Rm;
if (imm2 != 0) {
args << ", lsl #" << imm2;
}
args << "]";
}
} else if (op3 == 6) {
// STR.W Rt, [Rn, #imm12] - 111 11 000 110 0 nnnn tttt iiiiiiiiiiii
uint32_t imm12 = instr & 0xFFF;
opcode << "str.w";
args << Rt << ", [" << Rn << ", #" << imm12 << "]";
}
break;
}
}
break;
}
case 0x03: case 0x0B: case 0x13: case 0x1B: { // 00xx011
// Load halfword
// |111|11|10|0 0|00|0|0000|1111|110000|000000|
// |5 3|21|09|8 7|65|4|3 0|5 2|10 6|5 0|
// |---|--|--|---|--|-|----|----|------|------|
// |332|22|22|2 2|22|2|1111|1111|110000|000000|
// |1 9|87|65|4 3|21|0|9 6|5 2|10 6|5 0|
// |---|--|--|---|--|-|----|----|------|------|
// |111|11|00|op3|01|1| Rn | Rt | op4 | |
// |111|11| op2 | | | imm12 |
uint32_t op3 = (instr >> 23) & 3;
ArmRegister Rn(instr, 16);
ArmRegister Rt(instr, 12);
if (Rt.r != 15) {
if (op3 == 1) {
// LDRH.W Rt, [Rn, #imm12] - 111 11 00 01 011 nnnn tttt iiiiiiiiiiii
uint32_t imm12 = instr & 0xFFF;
opcode << "ldrh.w";
args << Rt << ", [" << Rn << ", #" << imm12 << "]";
if (Rn.r == 9) {
args << " ; ";
Thread::DumpThreadOffset(args, imm12, 4);
} else if (Rn.r == 15) {
intptr_t lit_adr = reinterpret_cast<intptr_t>(instr_ptr);
lit_adr = RoundDown(lit_adr, 4) + 4 + imm12;
args << " ; " << reinterpret_cast<void*>(*reinterpret_cast<int32_t*>(lit_adr));
}
} else if (op3 == 3) {
// LDRSH.W Rt, [Rn, #imm12] - 111 11 00 11 011 nnnn tttt iiiiiiiiiiii
uint32_t imm12 = instr & 0xFFF;
opcode << "ldrsh.w";
args << Rt << ", [" << Rn << ", #" << imm12 << "]";
if (Rn.r == 9) {
args << " ; ";
Thread::DumpThreadOffset(args, imm12, 4);
} else if (Rn.r == 15) {
intptr_t lit_adr = reinterpret_cast<intptr_t>(instr_ptr);
lit_adr = RoundDown(lit_adr, 4) + 4 + imm12;
args << " ; " << reinterpret_cast<void*>(*reinterpret_cast<int32_t*>(lit_adr));
}
}
}
break;
}
case 0x05: case 0x0D: case 0x15: case 0x1D: { // 00xx101
// Load word
// |111|11|10|0 0|00|0|0000|1111|110000|000000|
// |5 3|21|09|8 7|65|4|3 0|5 2|10 6|5 0|
// |---|--|--|---|--|-|----|----|------|------|
// |332|22|22|2 2|22|2|1111|1111|110000|000000|
// |1 9|87|65|4 3|21|0|9 6|5 2|10 6|5 0|
// |---|--|--|---|--|-|----|----|------|------|
// |111|11|00|op3|10|1| Rn | Rt | op4 | |
// |111|11| op2 | | | imm12 |
uint32_t op3 = (instr >> 23) & 3;
uint32_t op4 = (instr >> 6) & 0x3F;
ArmRegister Rn(instr, 16);
ArmRegister Rt(instr, 12);
if (op3 == 1 || Rn.r == 15) {
// LDR.W Rt, [Rn, #imm12] - 111 11 00 00 101 nnnn tttt iiiiiiiiiiii
// LDR.W Rt, [PC, #imm12] - 111 11 00 0x 101 1111 tttt iiiiiiiiiiii
uint32_t imm12 = instr & 0xFFF;
opcode << "ldr.w";
args << Rt << ", [" << Rn << ", #" << imm12 << "]";
if (Rn.r == 9) {
args << " ; ";
Thread::DumpThreadOffset(args, imm12, 4);
} else if (Rn.r == 15) {
intptr_t lit_adr = reinterpret_cast<intptr_t>(instr_ptr);
lit_adr = RoundDown(lit_adr, 4) + 4 + imm12;
args << " ; " << reinterpret_cast<void*>(*reinterpret_cast<int32_t*>(lit_adr));
}
} else if (op4 == 0) {
// LDR.W Rt, [Rn, Rm{, LSL #imm2}] - 111 11 00 00 101 nnnn tttt 000000iimmmm
uint32_t imm2 = (instr >> 4) & 0xF;
ArmRegister rm(instr, 0);
opcode << "ldr.w";
args << Rt << ", [" << Rn << ", " << rm;
if (imm2 != 0) {
args << ", lsl #" << imm2;
}
args << "]";
} else {
// LDRT Rt, [Rn, #imm8] - 111 11 00 00 101 nnnn tttt 1110iiiiiiii
uint32_t imm8 = instr & 0xFF;
opcode << "ldrt";
args << Rt << ", [" << Rn << ", #" << imm8 << "]";
}
break;
}
}
default:
break;
}
// Apply any IT-block conditions to the opcode if necessary.
if (!it_conditions_.empty()) {
opcode << it_conditions_.back();
it_conditions_.pop_back();
}
os << StringPrintf("%p: %08x\t%-7s ", instr_ptr, instr, opcode.str().c_str()) << args.str() << '\n';
return 4;
} // NOLINT(readability/fn_size)
size_t DisassemblerArm::DumpThumb16(std::ostream& os, const uint8_t* instr_ptr) {
uint16_t instr = ReadU16(instr_ptr);
bool is_32bit = ((instr & 0xF000) == 0xF000) || ((instr & 0xF800) == 0xE800);
if (is_32bit) {
return DumpThumb32(os, instr_ptr);
} else {
std::ostringstream opcode;
std::ostringstream args;
uint16_t opcode1 = instr >> 10;
if (opcode1 < 0x10) {
// shift (immediate), add, subtract, move, and compare
uint16_t opcode2 = instr >> 9;
switch (opcode2) {
case 0x0: case 0x1: case 0x2: case 0x3: case 0x4: case 0x5: case 0x6: case 0x7:
case 0x8: case 0x9: case 0xA: case 0xB: {
// Logical shift left - 00 000xx iii mmm ddd
// Logical shift right - 00 001xx iii mmm ddd
// Arithmetic shift right - 00 010xx iii mmm ddd
uint16_t imm5 = (instr >> 6) & 0x1F;
ThumbRegister rm(instr, 3);
ThumbRegister Rd(instr, 0);
if (opcode2 <= 3) {
opcode << "lsls";
} else if (opcode2 <= 7) {
opcode << "lsrs";
} else {
opcode << "asrs";
}
args << Rd << ", " << rm << ", #" << imm5;
break;
}
case 0xC: case 0xD: case 0xE: case 0xF: {
// Add register - 00 01100 mmm nnn ddd
// Sub register - 00 01101 mmm nnn ddd
// Add 3-bit immediate - 00 01110 iii nnn ddd
// Sub 3-bit immediate - 00 01111 iii nnn ddd
uint16_t imm3_or_Rm = (instr >> 6) & 7;
ThumbRegister Rn(instr, 3);
ThumbRegister Rd(instr, 0);
if ((opcode2 & 2) != 0 && imm3_or_Rm == 0) {
opcode << "mov";
} else {
if ((opcode2 & 1) == 0) {
opcode << "adds";
} else {
opcode << "subs";
}
}
args << Rd << ", " << Rn;
if ((opcode2 & 2) == 0) {
ArmRegister Rm(imm3_or_Rm);
args << ", " << Rm;
} else if (imm3_or_Rm != 0) {
args << ", #" << imm3_or_Rm;
}
break;
}
case 0x10: case 0x11: case 0x12: case 0x13:
case 0x14: case 0x15: case 0x16: case 0x17:
case 0x18: case 0x19: case 0x1A: case 0x1B:
case 0x1C: case 0x1D: case 0x1E: case 0x1F: {
// MOVS Rd, #imm8 - 00100 ddd iiiiiiii
// CMP Rn, #imm8 - 00101 nnn iiiiiiii
// ADDS Rn, #imm8 - 00110 nnn iiiiiiii
// SUBS Rn, #imm8 - 00111 nnn iiiiiiii
ThumbRegister Rn(instr, 8);
uint16_t imm8 = instr & 0xFF;
switch (opcode2 >> 2) {
case 4: opcode << "movs"; break;
case 5: opcode << "cmp"; break;
case 6: opcode << "adds"; break;
case 7: opcode << "subs"; break;
}
args << Rn << ", #" << imm8;
break;
}
default:
break;
}
} else if (opcode1 == 0x10) {
// Data-processing
uint16_t opcode2 = (instr >> 6) & 0xF;
ThumbRegister rm(instr, 3);
ThumbRegister rdn(instr, 0);
opcode << kThumbDataProcessingOperations[opcode2];
args << rdn << ", " << rm;
} else if (opcode1 == 0x11) {
// Special data instructions and branch and exchange
uint16_t opcode2 = (instr >> 6) & 0x0F;
switch (opcode2) {
case 0x0: case 0x1: case 0x2: case 0x3: {
// Add low registers - 010001 0000 xxxxxx
// Add high registers - 010001 0001/001x xxxxxx
uint16_t DN = (instr >> 7) & 1;
ArmRegister rm(instr, 3);
uint16_t Rdn = instr & 7;
ArmRegister DN_Rdn((DN << 3) | Rdn);
opcode << "add";
args << DN_Rdn << ", " << rm;
break;
}
case 0x8: case 0x9: case 0xA: case 0xB: {
// Move low registers - 010001 1000 xxxxxx
// Move high registers - 010001 1001/101x xxxxxx
uint16_t DN = (instr >> 7) & 1;
ArmRegister rm(instr, 3);
uint16_t Rdn = instr & 7;
ArmRegister DN_Rdn((DN << 3) | Rdn);
opcode << "mov";
args << DN_Rdn << ", " << rm;
break;
}
case 0x5: case 0x6: case 0x7: {
// Compare high registers - 010001 0101/011x xxxxxx
uint16_t N = (instr >> 7) & 1;
ArmRegister rm(instr, 3);
uint16_t Rn = instr & 7;
ArmRegister N_Rn((N << 3) | Rn);
opcode << "cmp";
args << N_Rn << ", " << rm;
break;
}
case 0xC: case 0xD: case 0xE: case 0xF: {
// Branch and exchange - 010001 110x xxxxxx
// Branch with link and exchange - 010001 111x xxxxxx
ArmRegister rm(instr, 3);
opcode << ((opcode2 & 0x2) == 0 ? "bx" : "blx");
args << rm;
break;
}
default:
break;
}
} else if (opcode1 == 0x12 || opcode1 == 0x13) { // 01001x
ThumbRegister Rt(instr, 8);
uint16_t imm8 = instr & 0xFF;
opcode << "ldr";
args << Rt << ", [pc, #" << (imm8 << 2) << "]";
} else if ((opcode1 >= 0x14 && opcode1 <= 0x17) || // 0101xx
(opcode1 >= 0x18 && opcode1 <= 0x1f) || // 011xxx
(opcode1 >= 0x20 && opcode1 <= 0x27)) { // 100xxx
// Load/store single data item
uint16_t opA = (instr >> 12) & 0xF;
if (opA == 0x5) {
uint16_t opB = (instr >> 9) & 0x7;
ThumbRegister Rm(instr, 6);
ThumbRegister Rn(instr, 3);
ThumbRegister Rt(instr, 0);
switch (opB) {
case 0: opcode << "str"; break;
case 1: opcode << "strh"; break;
case 2: opcode << "strb"; break;
case 3: opcode << "ldrsb"; break;
case 4: opcode << "ldr"; break;
case 5: opcode << "ldrh"; break;
case 6: opcode << "ldrb"; break;
case 7: opcode << "ldrsh"; break;
}
args << Rt << ", [" << Rn << ", " << Rm << "]";
} else if (opA == 9) {
uint16_t opB = (instr >> 11) & 1;
ThumbRegister Rt(instr, 8);
uint16_t imm8 = instr & 0xFF;
opcode << (opB == 0 ? "str" : "ldr");
args << Rt << ", [sp, #" << (imm8 << 2) << "]";
} else {
uint16_t imm5 = (instr >> 6) & 0x1F;
uint16_t opB = (instr >> 11) & 1;
ThumbRegister Rn(instr, 3);
ThumbRegister Rt(instr, 0);
switch (opA) {
case 6:
imm5 <<= 2;
opcode << (opB == 0 ? "str" : "ldr");
break;
case 7:
imm5 <<= 0;
opcode << (opB == 0 ? "strb" : "ldrb");
break;
case 8:
imm5 <<= 1;
opcode << (opB == 0 ? "strh" : "ldrh");
break;
}
args << Rt << ", [" << Rn << ", #" << imm5 << "]";
}
} else if (opcode1 >= 0x34 && opcode1 <= 0x37) { // 1101xx
int8_t imm8 = instr & 0xFF;
uint32_t cond = (instr >> 8) & 0xF;
opcode << "b";
DumpCond(opcode, cond);
DumpBranchTarget(args, instr_ptr + 4, (imm8 << 1));
} else if ((instr & 0xF800) == 0xA800) {
// Generate SP-relative address
ThumbRegister rd(instr, 8);
int imm8 = instr & 0xFF;
opcode << "add";
args << rd << ", sp, #" << (imm8 << 2);
} else if ((instr & 0xF000) == 0xB000) {
// Miscellaneous 16-bit instructions
uint16_t opcode2 = (instr >> 5) & 0x7F;
switch (opcode2) {
case 0x00: case 0x01: case 0x02: case 0x03: case 0x04: case 0x05: case 0x06: case 0x07: {
// Add immediate to SP - 1011 00000 ii iiiii
// Subtract immediate from SP - 1011 00001 ii iiiii
int imm7 = instr & 0x7F;
opcode << ((opcode2 & 4) == 0 ? "add" : "sub");
args << "sp, sp, #" << (imm7 << 2);
break;
}
case 0x08: case 0x09: case 0x0A: case 0x0B: // 0001xxx
case 0x0C: case 0x0D: case 0x0E: case 0x0F:
case 0x18: case 0x19: case 0x1A: case 0x1B: // 0011xxx
case 0x1C: case 0x1D: case 0x1E: case 0x1F:
case 0x48: case 0x49: case 0x4A: case 0x4B: // 1001xxx
case 0x4C: case 0x4D: case 0x4E: case 0x4F:
case 0x58: case 0x59: case 0x5A: case 0x5B: // 1011xxx
case 0x5C: case 0x5D: case 0x5E: case 0x5F: {
// CBNZ, CBZ
uint16_t op = (instr >> 11) & 1;
uint16_t i = (instr >> 9) & 1;
uint16_t imm5 = (instr >> 3) & 0x1F;
ThumbRegister Rn(instr, 0);
opcode << (op != 0 ? "cbnz" : "cbz");
uint32_t imm32 = (i << 6) | (imm5 << 1);
args << Rn << ", ";
DumpBranchTarget(args, instr_ptr + 4, imm32);
break;
}
case 0x78: case 0x79: case 0x7A: case 0x7B: // 1111xxx
case 0x7C: case 0x7D: case 0x7E: case 0x7F: {
// If-Then, and hints
uint16_t opA = (instr >> 4) & 0xF;
uint16_t opB = instr & 0xF;
if (opB == 0) {
switch (opA) {
case 0: opcode << "nop"; break;
case 1: opcode << "yield"; break;
case 2: opcode << "wfe"; break;
case 3: opcode << "sev"; break;
default: break;
}
} else {
uint32_t first_cond = opA;
uint32_t mask = opB;
opcode << "it";
// Flesh out the base "it" opcode with the specific collection of 't's and 'e's,
// and store up the actual condition codes we'll want to add to the next few opcodes.
size_t count = 3 - CTZ(mask);
it_conditions_.resize(count + 2); // Plus the implicit 't', plus the "" for the IT itself.
for (size_t i = 0; i < count; ++i) {
bool positive_cond = ((first_cond & 1) != 0);
bool positive_mask = ((mask & (1 << (3 - i))) != 0);
if (positive_mask == positive_cond) {
opcode << 't';
it_conditions_[i] = kConditionCodeNames[first_cond];
} else {
opcode << 'e';
it_conditions_[i] = kConditionCodeNames[first_cond ^ 1];
}
}
it_conditions_[count] = kConditionCodeNames[first_cond]; // The implicit 't'.
it_conditions_[count + 1] = ""; // No condition code for the IT itself...
DumpCond(args, first_cond); // ...because it's considered an argument.
}
break;
}
default:
break;
}
} else if (((instr & 0xF000) == 0x5000) || ((instr & 0xE000) == 0x6000) ||
((instr & 0xE000) == 0x8000)) {
// Load/store single data item
uint16_t opA = instr >> 12;
// uint16_t opB = (instr >> 9) & 7;
switch (opA) {
case 0x6: {
// STR Rt, [Rn, #imm] - 01100 iiiii nnn ttt
// LDR Rt, [Rn, #imm] - 01101 iiiii nnn ttt
uint16_t imm5 = (instr >> 6) & 0x1F;
ThumbRegister Rn(instr, 3);
ThumbRegister Rt(instr, 0);
opcode << ((instr & 0x800) == 0 ? "str" : "ldr");
args << Rt << ", [" << Rn << ", #" << (imm5 << 2) << "]";
break;
}
case 0x9: {
// STR Rt, [SP, #imm] - 01100 ttt iiiiiiii
// LDR Rt, [SP, #imm] - 01101 ttt iiiiiiii
uint16_t imm8 = instr & 0xFF;
ThumbRegister Rt(instr, 8);
opcode << ((instr & 0x800) == 0 ? "str" : "ldr");
args << Rt << ", [sp, #" << (imm8 << 2) << "]";
break;
}
default:
break;
}
} else if (opcode1 == 0x38 || opcode1 == 0x39) {
uint16_t imm11 = instr & 0x7FFF;
int32_t imm32 = imm11 << 1;
imm32 = (imm32 << 20) >> 20; // sign extend 12 bit immediate
opcode << "b";
DumpBranchTarget(args, instr_ptr + 4, imm32);
}
// Apply any IT-block conditions to the opcode if necessary.
if (!it_conditions_.empty()) {
opcode << it_conditions_.back();
it_conditions_.pop_back();
}
os << StringPrintf("%p: %04x \t%-7s ", instr_ptr, instr, opcode.str().c_str()) << args.str() << '\n';
}
return 2;
}
} // namespace arm
} // namespace art