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// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include <setjmp.h> // NOLINT
#include <stdlib.h>
#include "vm/globals.h"
#if defined(TARGET_ARCH_ARM)
// Only build the simulator if not compiling for real ARM hardware.
#if defined(USING_SIMULATOR)
#include "vm/simulator.h"
#include "vm/compiler/assembler/assembler.h"
#include "vm/compiler/assembler/disassembler.h"
#include "vm/constants_arm.h"
#include "vm/cpu.h"
#include "vm/native_arguments.h"
#include "vm/os_thread.h"
#include "vm/stack_frame.h"
namespace dart {
DEFINE_FLAG(uint64_t,
trace_sim_after,
ULLONG_MAX,
"Trace simulator execution after instruction count reached.");
DEFINE_FLAG(uint64_t,
stop_sim_at,
ULLONG_MAX,
"Instruction address or instruction count to stop simulator at.");
// This macro provides a platform independent use of sscanf. The reason for
// SScanF not being implemented in a platform independent way through
// OS in the same way as SNPrint is that the Windows C Run-Time
// Library does not provide vsscanf.
#define SScanF sscanf // NOLINT
// SimulatorSetjmpBuffer are linked together, and the last created one
// is referenced by the Simulator. When an exception is thrown, the exception
// runtime looks at where to jump and finds the corresponding
// SimulatorSetjmpBuffer based on the stack pointer of the exception handler.
// The runtime then does a Longjmp on that buffer to return to the simulator.
class SimulatorSetjmpBuffer {
public:
void Longjmp() {
// "This" is now the last setjmp buffer.
simulator_->set_last_setjmp_buffer(this);
longjmp(buffer_, 1);
}
explicit SimulatorSetjmpBuffer(Simulator* sim) {
simulator_ = sim;
link_ = sim->last_setjmp_buffer();
sim->set_last_setjmp_buffer(this);
sp_ = static_cast<uword>(sim->get_register(SP));
}
~SimulatorSetjmpBuffer() {
ASSERT(simulator_->last_setjmp_buffer() == this);
simulator_->set_last_setjmp_buffer(link_);
}
SimulatorSetjmpBuffer* link() { return link_; }
uword sp() { return sp_; }
private:
uword sp_;
Simulator* simulator_;
SimulatorSetjmpBuffer* link_;
jmp_buf buffer_;
friend class Simulator;
};
// The SimulatorDebugger class is used by the simulator while debugging
// simulated ARM code.
class SimulatorDebugger {
public:
explicit SimulatorDebugger(Simulator* sim);
~SimulatorDebugger();
void Stop(Instr* instr, const char* message);
void Debug();
char* ReadLine(const char* prompt);
private:
Simulator* sim_;
bool GetValue(char* desc, uint32_t* value);
bool GetFValue(char* desc, float* value);
bool GetDValue(char* desc, double* value);
static TokenPosition GetApproximateTokenIndex(const Code& code, uword pc);
static void PrintDartFrame(uword pc,
uword fp,
uword sp,
const Function& function,
TokenPosition token_pos,
bool is_optimized,
bool is_inlined);
void PrintBacktrace();
// Set or delete a breakpoint. Returns true if successful.
bool SetBreakpoint(Instr* breakpc);
bool DeleteBreakpoint(Instr* breakpc);
// Undo and redo all breakpoints. This is needed to bracket disassembly and
// execution to skip past breakpoints when run from the debugger.
void UndoBreakpoints();
void RedoBreakpoints();
};
SimulatorDebugger::SimulatorDebugger(Simulator* sim) {
sim_ = sim;
}
SimulatorDebugger::~SimulatorDebugger() {}
void SimulatorDebugger::Stop(Instr* instr, const char* message) {
OS::PrintErr("Simulator hit %s\n", message);
Debug();
}
static Register LookupCpuRegisterByName(const char* name) {
static const char* kNames[] = {
"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
"r11", "r12", "r13", "r14", "r15", "pc", "lr", "sp", "ip", "fp", "pp"};
static const Register kRegisters[] = {R0, R1, R2, R3, R4, R5, R6, R7,
R8, R9, R10, R11, R12, R13, R14, R15,
PC, LR, SP, IP, FP, PP};
ASSERT(ARRAY_SIZE(kNames) == ARRAY_SIZE(kRegisters));
for (unsigned i = 0; i < ARRAY_SIZE(kNames); i++) {
if (strcmp(kNames[i], name) == 0) {
return kRegisters[i];
}
}
return kNoRegister;
}
static SRegister LookupSRegisterByName(const char* name) {
int reg_nr = -1;
bool ok = SScanF(name, "s%d", &reg_nr);
if (ok && (0 <= reg_nr) && (reg_nr < kNumberOfSRegisters)) {
return static_cast<SRegister>(reg_nr);
}
return kNoSRegister;
}
static DRegister LookupDRegisterByName(const char* name) {
int reg_nr = -1;
bool ok = SScanF(name, "d%d", &reg_nr);
if (ok && (0 <= reg_nr) && (reg_nr < kNumberOfDRegisters)) {
return static_cast<DRegister>(reg_nr);
}
return kNoDRegister;
}
bool SimulatorDebugger::GetValue(char* desc, uint32_t* value) {
Register reg = LookupCpuRegisterByName(desc);
if (reg != kNoRegister) {
if (reg == PC) {
*value = sim_->get_pc();
} else {
*value = sim_->get_register(reg);
}
return true;
}
if (desc[0] == '*') {
uint32_t addr;
if (GetValue(desc + 1, &addr)) {
if (Simulator::IsIllegalAddress(addr)) {
return false;
}
*value = *(reinterpret_cast<uint32_t*>(addr));
return true;
}
}
bool retval = SScanF(desc, "0x%x", value) == 1;
if (!retval) {
retval = SScanF(desc, "%x", value) == 1;
}
return retval;
}
bool SimulatorDebugger::GetFValue(char* desc, float* value) {
SRegister sreg = LookupSRegisterByName(desc);
if (sreg != kNoSRegister) {
*value = sim_->get_sregister(sreg);
return true;
}
if (desc[0] == '*') {
uint32_t addr;
if (GetValue(desc + 1, &addr)) {
if (Simulator::IsIllegalAddress(addr)) {
return false;
}
*value = *(reinterpret_cast<float*>(addr));
return true;
}
}
return false;
}
bool SimulatorDebugger::GetDValue(char* desc, double* value) {
DRegister dreg = LookupDRegisterByName(desc);
if (dreg != kNoDRegister) {
*value = sim_->get_dregister(dreg);
return true;
}
if (desc[0] == '*') {
uint32_t addr;
if (GetValue(desc + 1, &addr)) {
if (Simulator::IsIllegalAddress(addr)) {
return false;
}
*value = *(reinterpret_cast<double*>(addr));
return true;
}
}
return false;
}
TokenPosition SimulatorDebugger::GetApproximateTokenIndex(const Code& code,
uword pc) {
TokenPosition token_pos = TokenPosition::kNoSource;
uword pc_offset = pc - code.PayloadStart();
const PcDescriptors& descriptors =
PcDescriptors::Handle(code.pc_descriptors());
PcDescriptors::Iterator iter(descriptors, RawPcDescriptors::kAnyKind);
while (iter.MoveNext()) {
if (iter.PcOffset() == pc_offset) {
return iter.TokenPos();
} else if (!token_pos.IsReal() && (iter.PcOffset() > pc_offset)) {
token_pos = iter.TokenPos();
}
}
return token_pos;
}
void SimulatorDebugger::PrintDartFrame(uword pc,
uword fp,
uword sp,
const Function& function,
TokenPosition token_pos,
bool is_optimized,
bool is_inlined) {
const Script& script = Script::Handle(function.script());
const String& func_name = String::Handle(function.QualifiedScrubbedName());
const String& url = String::Handle(script.url());
intptr_t line = -1;
intptr_t column = -1;
if (token_pos.IsReal()) {
script.GetTokenLocation(token_pos, &line, &column);
}
OS::PrintErr(
"pc=0x%" Px " fp=0x%" Px " sp=0x%" Px " %s%s (%s:%" Pd ":%" Pd ")\n", pc,
fp, sp, is_optimized ? (is_inlined ? "inlined " : "optimized ") : "",
func_name.ToCString(), url.ToCString(), line, column);
}
void SimulatorDebugger::PrintBacktrace() {
StackFrameIterator frames(
sim_->get_register(FP), sim_->get_register(SP), sim_->get_pc(),
ValidationPolicy::kDontValidateFrames, Thread::Current(),
StackFrameIterator::kNoCrossThreadIteration);
StackFrame* frame = frames.NextFrame();
ASSERT(frame != NULL);
Function& function = Function::Handle();
Function& inlined_function = Function::Handle();
Code& code = Code::Handle();
Code& unoptimized_code = Code::Handle();
while (frame != NULL) {
if (frame->IsDartFrame()) {
ASSERT(!frame->is_interpreted()); // Not yet supported.
code = frame->LookupDartCode();
function = code.function();
if (code.is_optimized()) {
// For optimized frames, extract all the inlined functions if any
// into the stack trace.
InlinedFunctionsIterator it(code, frame->pc());
while (!it.Done()) {
// Print each inlined frame with its pc in the corresponding
// unoptimized frame.
inlined_function = it.function();
unoptimized_code = it.code();
uword unoptimized_pc = it.pc();
it.Advance();
if (!it.Done()) {
PrintDartFrame(
unoptimized_pc, frame->fp(), frame->sp(), inlined_function,
GetApproximateTokenIndex(unoptimized_code, unoptimized_pc),
true, true);
}
}
// Print the optimized inlining frame below.
}
PrintDartFrame(frame->pc(), frame->fp(), frame->sp(), function,
GetApproximateTokenIndex(code, frame->pc()),
code.is_optimized(), false);
} else {
OS::PrintErr("pc=0x%" Px " fp=0x%" Px " sp=0x%" Px " %s frame\n",
frame->pc(), frame->fp(), frame->sp(),
frame->IsEntryFrame()
? "entry"
: frame->IsExitFrame()
? "exit"
: frame->IsStubFrame() ? "stub" : "invalid");
}
frame = frames.NextFrame();
}
}
bool SimulatorDebugger::SetBreakpoint(Instr* breakpc) {
// Check if a breakpoint can be set. If not return without any side-effects.
if (sim_->break_pc_ != NULL) {
return false;
}
// Set the breakpoint.
sim_->break_pc_ = breakpc;
sim_->break_instr_ = breakpc->InstructionBits();
// Not setting the breakpoint instruction in the code itself. It will be set
// when the debugger shell continues.
return true;
}
bool SimulatorDebugger::DeleteBreakpoint(Instr* breakpc) {
if (sim_->break_pc_ != NULL) {
sim_->break_pc_->SetInstructionBits(sim_->break_instr_);
}
sim_->break_pc_ = NULL;
sim_->break_instr_ = 0;
return true;
}
void SimulatorDebugger::UndoBreakpoints() {
if (sim_->break_pc_ != NULL) {
sim_->break_pc_->SetInstructionBits(sim_->break_instr_);
}
}
void SimulatorDebugger::RedoBreakpoints() {
if (sim_->break_pc_ != NULL) {
sim_->break_pc_->SetInstructionBits(Instr::kSimulatorBreakpointInstruction);
}
}
void SimulatorDebugger::Debug() {
intptr_t last_pc = -1;
bool done = false;
#define COMMAND_SIZE 63
#define ARG_SIZE 255
#define STR(a) #a
#define XSTR(a) STR(a)
char cmd[COMMAND_SIZE + 1];
char arg1[ARG_SIZE + 1];
char arg2[ARG_SIZE + 1];
// make sure to have a proper terminating character if reaching the limit
cmd[COMMAND_SIZE] = 0;
arg1[ARG_SIZE] = 0;
arg2[ARG_SIZE] = 0;
// Undo all set breakpoints while running in the debugger shell. This will
// make them invisible to all commands.
UndoBreakpoints();
while (!done) {
if (last_pc != sim_->get_pc()) {
last_pc = sim_->get_pc();
if (Simulator::IsIllegalAddress(last_pc)) {
OS::PrintErr("pc is out of bounds: 0x%" Px "\n", last_pc);
} else {
if (FLAG_support_disassembler) {
Disassembler::Disassemble(last_pc, last_pc + Instr::kInstrSize);
} else {
OS::PrintErr("Disassembler not supported in this mode.\n");
}
}
}
char* line = ReadLine("sim> ");
if (line == NULL) {
FATAL("ReadLine failed");
} else {
// Use sscanf to parse the individual parts of the command line. At the
// moment no command expects more than two parameters.
int args = SScanF(line,
"%" XSTR(COMMAND_SIZE) "s "
"%" XSTR(ARG_SIZE) "s "
"%" XSTR(ARG_SIZE) "s",
cmd, arg1, arg2);
if ((strcmp(cmd, "h") == 0) || (strcmp(cmd, "help") == 0)) {
OS::PrintErr(
"c/cont -- continue execution\n"
"disasm -- disassemble instrs at current pc location\n"
" other variants are:\n"
" disasm <address>\n"
" disasm <address> <number_of_instructions>\n"
" by default 10 instrs are disassembled\n"
"del -- delete breakpoints\n"
"flags -- print flag values\n"
"gdb -- transfer control to gdb\n"
"h/help -- print this help string\n"
"break <address> -- set break point at specified address\n"
"p/print <reg or icount or value or *addr> -- print integer\n"
"ps/printsingle <sreg or *addr> -- print float value\n"
"pd/printdouble <dreg or *addr> -- print double value\n"
"po/printobject <*reg or *addr> -- print object\n"
"si/stepi -- single step an instruction\n"
"trace -- toggle execution tracing mode\n"
"bt -- print backtrace\n"
"unstop -- if current pc is a stop instr make it a nop\n"
"q/quit -- Quit the debugger and exit the program\n");
} else if ((strcmp(cmd, "quit") == 0) || (strcmp(cmd, "q") == 0)) {
OS::PrintErr("Quitting\n");
OS::Exit(0);
} else if ((strcmp(cmd, "si") == 0) || (strcmp(cmd, "stepi") == 0)) {
sim_->InstructionDecode(reinterpret_cast<Instr*>(sim_->get_pc()));
} else if ((strcmp(cmd, "c") == 0) || (strcmp(cmd, "cont") == 0)) {
// Execute the one instruction we broke at with breakpoints disabled.
sim_->InstructionDecode(reinterpret_cast<Instr*>(sim_->get_pc()));
// Leave the debugger shell.
done = true;
} else if ((strcmp(cmd, "p") == 0) || (strcmp(cmd, "print") == 0)) {
if (args == 2) {
uint32_t value;
if (strcmp(arg1, "icount") == 0) {
const uint64_t icount = sim_->get_icount();
OS::PrintErr("icount: %" Pu64 " 0x%" Px64 "\n", icount, icount);
} else if (GetValue(arg1, &value)) {
OS::PrintErr("%s: %u 0x%x\n", arg1, value, value);
} else {
OS::PrintErr("%s unrecognized\n", arg1);
}
} else {
OS::PrintErr("print <reg or icount or value or *addr>\n");
}
} else if ((strcmp(cmd, "ps") == 0) ||
(strcmp(cmd, "printsingle") == 0)) {
if (args == 2) {
float fvalue;
if (GetFValue(arg1, &fvalue)) {
uint32_t value = bit_cast<uint32_t, float>(fvalue);
OS::PrintErr("%s: 0%u 0x%x %.8g\n", arg1, value, value, fvalue);
} else {
OS::PrintErr("%s unrecognized\n", arg1);
}
} else {
OS::PrintErr("printfloat <sreg or *addr>\n");
}
} else if ((strcmp(cmd, "pd") == 0) ||
(strcmp(cmd, "printdouble") == 0)) {
if (args == 2) {
double dvalue;
if (GetDValue(arg1, &dvalue)) {
uint64_t long_value = bit_cast<uint64_t, double>(dvalue);
OS::PrintErr("%s: %llu 0x%llx %.8g\n", arg1, long_value, long_value,
dvalue);
} else {
OS::PrintErr("%s unrecognized\n", arg1);
}
} else {
OS::PrintErr("printdouble <dreg or *addr>\n");
}
} else if ((strcmp(cmd, "po") == 0) ||
(strcmp(cmd, "printobject") == 0)) {
if (args == 2) {
uint32_t value;
// Make the dereferencing '*' optional.
if (((arg1[0] == '*') && GetValue(arg1 + 1, &value)) ||
GetValue(arg1, &value)) {
if (Isolate::Current()->heap()->Contains(value)) {
OS::PrintErr("%s: \n", arg1);
#if defined(DEBUG)
const Object& obj =
Object::Handle(reinterpret_cast<RawObject*>(value));
obj.Print();
#endif // defined(DEBUG)
} else {
OS::PrintErr("0x%x is not an object reference\n", value);
}
} else {
OS::PrintErr("%s unrecognized\n", arg1);
}
} else {
OS::PrintErr("printobject <*reg or *addr>\n");
}
} else if (strcmp(cmd, "disasm") == 0) {
uint32_t start = 0;
uint32_t end = 0;
if (args == 1) {
start = sim_->get_pc();
end = start + (10 * Instr::kInstrSize);
} else if (args == 2) {
if (GetValue(arg1, &start)) {
// No length parameter passed, assume 10 instructions.
if (Simulator::IsIllegalAddress(start)) {
// If start isn't a valid address, warn and use PC instead.
OS::PrintErr("First argument yields invalid address: 0x%x\n",
start);
OS::PrintErr("Using PC instead\n");
start = sim_->get_pc();
}
end = start + (10 * Instr::kInstrSize);
}
} else {
uint32_t length;
if (GetValue(arg1, &start) && GetValue(arg2, &length)) {
if (Simulator::IsIllegalAddress(start)) {
// If start isn't a valid address, warn and use PC instead.
OS::PrintErr("First argument yields invalid address: 0x%x\n",
start);
OS::PrintErr("Using PC instead\n");
start = sim_->get_pc();
}
end = start + (length * Instr::kInstrSize);
}
}
if ((start > 0) && (end > start)) {
if (FLAG_support_disassembler) {
Disassembler::Disassemble(start, end);
} else {
OS::PrintErr("Disassembler not supported in this mode.\n");
}
} else {
OS::PrintErr("disasm [<address> [<number_of_instructions>]]\n");
}
} else if (strcmp(cmd, "gdb") == 0) {
OS::PrintErr("relinquishing control to gdb\n");
OS::DebugBreak();
OS::PrintErr("regaining control from gdb\n");
} else if (strcmp(cmd, "break") == 0) {
if (args == 2) {
uint32_t addr;
if (GetValue(arg1, &addr)) {
if (!SetBreakpoint(reinterpret_cast<Instr*>(addr))) {
OS::PrintErr("setting breakpoint failed\n");
}
} else {
OS::PrintErr("%s unrecognized\n", arg1);
}
} else {
OS::PrintErr("break <addr>\n");
}
} else if (strcmp(cmd, "del") == 0) {
if (!DeleteBreakpoint(NULL)) {
OS::PrintErr("deleting breakpoint failed\n");
}
} else if (strcmp(cmd, "flags") == 0) {
OS::PrintErr("APSR: ");
OS::PrintErr("N flag: %d; ", sim_->n_flag_);
OS::PrintErr("Z flag: %d; ", sim_->z_flag_);
OS::PrintErr("C flag: %d; ", sim_->c_flag_);
OS::PrintErr("V flag: %d\n", sim_->v_flag_);
OS::PrintErr("FPSCR: ");
OS::PrintErr("N flag: %d; ", sim_->fp_n_flag_);
OS::PrintErr("Z flag: %d; ", sim_->fp_z_flag_);
OS::PrintErr("C flag: %d; ", sim_->fp_c_flag_);
OS::PrintErr("V flag: %d\n", sim_->fp_v_flag_);
} else if (strcmp(cmd, "unstop") == 0) {
intptr_t stop_pc = sim_->get_pc() - Instr::kInstrSize;
Instr* stop_instr = reinterpret_cast<Instr*>(stop_pc);
if (stop_instr->IsSvc() || stop_instr->IsBkpt()) {
stop_instr->SetInstructionBits(Instr::kNopInstruction);
} else {
OS::PrintErr("Not at debugger stop.\n");
}
} else if (strcmp(cmd, "trace") == 0) {
if (FLAG_trace_sim_after == ULLONG_MAX) {
FLAG_trace_sim_after = sim_->get_icount();
OS::PrintErr("execution tracing on\n");
} else {
FLAG_trace_sim_after = ULLONG_MAX;
OS::PrintErr("execution tracing off\n");
}
} else if (strcmp(cmd, "bt") == 0) {
PrintBacktrace();
} else {
OS::PrintErr("Unknown command: %s\n", cmd);
}
}
delete[] line;
}
// Add all the breakpoints back to stop execution and enter the debugger
// shell when hit.
RedoBreakpoints();
#undef COMMAND_SIZE
#undef ARG_SIZE
#undef STR
#undef XSTR
}
char* SimulatorDebugger::ReadLine(const char* prompt) {
char* result = NULL;
char line_buf[256];
intptr_t offset = 0;
bool keep_going = true;
OS::PrintErr("%s", prompt);
while (keep_going) {
if (fgets(line_buf, sizeof(line_buf), stdin) == NULL) {
// fgets got an error. Just give up.
if (result != NULL) {
delete[] result;
}
return NULL;
}
intptr_t len = strlen(line_buf);
if (len > 1 && line_buf[len - 2] == '\\' && line_buf[len - 1] == '\n') {
// When we read a line that ends with a "\" we remove the escape and
// append the remainder.
line_buf[len - 2] = '\n';
line_buf[len - 1] = 0;
len -= 1;
} else if ((len > 0) && (line_buf[len - 1] == '\n')) {
// Since we read a new line we are done reading the line. This
// will exit the loop after copying this buffer into the result.
keep_going = false;
}
if (result == NULL) {
// Allocate the initial result and make room for the terminating '\0'
result = new char[len + 1];
if (result == NULL) {
// OOM, so cannot readline anymore.
return NULL;
}
} else {
// Allocate a new result with enough room for the new addition.
intptr_t new_len = offset + len + 1;
char* new_result = new char[new_len];
if (new_result == NULL) {
// OOM, free the buffer allocated so far and return NULL.
delete[] result;
return NULL;
} else {
// Copy the existing input into the new array and set the new
// array as the result.
memmove(new_result, result, offset);
delete[] result;
result = new_result;
}
}
// Copy the newly read line into the result.
memmove(result + offset, line_buf, len);
offset += len;
}
ASSERT(result != NULL);
result[offset] = '\0';
return result;
}
void Simulator::Init() {}
Simulator::Simulator() : exclusive_access_addr_(0), exclusive_access_value_(0) {
// Setup simulator support first. Some of this information is needed to
// setup the architecture state.
// We allocate the stack here, the size is computed as the sum of
// the size specified by the user and the buffer space needed for
// handling stack overflow exceptions. To be safe in potential
// stack underflows we also add some underflow buffer space.
stack_ =
new char[(OSThread::GetSpecifiedStackSize() +
OSThread::kStackSizeBufferMax + kSimulatorStackUnderflowSize)];
// Low address.
stack_limit_ = reinterpret_cast<uword>(stack_);
// Limit for StackOverflowError.
overflow_stack_limit_ = stack_limit_ + OSThread::kStackSizeBufferMax;
// High address.
stack_base_ = overflow_stack_limit_ + OSThread::GetSpecifiedStackSize();
pc_modified_ = false;
icount_ = 0;
break_pc_ = NULL;
break_instr_ = 0;
last_setjmp_buffer_ = NULL;
// Setup architecture state.
// All registers are initialized to zero to start with.
for (int i = 0; i < kNumberOfCpuRegisters; i++) {
registers_[i] = 0;
}
n_flag_ = false;
z_flag_ = false;
c_flag_ = false;
v_flag_ = false;
// The sp is initialized to point to the bottom (high address) of the
// allocated stack area.
registers_[SP] = stack_base();
// The lr and pc are initialized to a known bad value that will cause an
// access violation if the simulator ever tries to execute it.
registers_[PC] = kBadLR;
registers_[LR] = kBadLR;
// All double-precision registers are initialized to zero.
for (int i = 0; i < kNumberOfDRegisters; i++) {
dregisters_[i] = 0;
}
// Since VFP registers are overlapping, single-precision registers should
// already be initialized.
ASSERT(2 * kNumberOfDRegisters >= kNumberOfSRegisters);
for (int i = 0; i < kNumberOfSRegisters; i++) {
ASSERT(sregisters_[i] == 0.0);
}
fp_n_flag_ = false;
fp_z_flag_ = false;
fp_c_flag_ = false;
fp_v_flag_ = false;
}
Simulator::~Simulator() {
delete[] stack_;
Isolate* isolate = Isolate::Current();
if (isolate != NULL) {
isolate->set_simulator(NULL);
}
}
// When the generated code calls an external reference we need to catch that in
// the simulator. The external reference will be a function compiled for the
// host architecture. We need to call that function instead of trying to
// execute it with the simulator. We do that by redirecting the external
// reference to a svc (supervisor call) instruction that is handled by
// the simulator. We write the original destination of the jump just at a known
// offset from the svc instruction so the simulator knows what to call.
class Redirection {
public:
uword address_of_svc_instruction() {
return reinterpret_cast<uword>(&svc_instruction_);
}
uword external_function() const { return external_function_; }
Simulator::CallKind call_kind() const { return call_kind_; }
int argument_count() const { return argument_count_; }
static Redirection* Get(uword external_function,
Simulator::CallKind call_kind,
int argument_count) {
MutexLocker ml(mutex_);
for (Redirection* current = list_; current != NULL;
current = current->next_) {
if (current->external_function_ == external_function) return current;
}
Redirection* redirection =
new Redirection(external_function, call_kind, argument_count);
redirection->next_ = list_;
// Use a memory fence to ensure all pending writes are written at the time
// of updating the list head, so the profiling thread always has a valid
// list to look at.
Redirection* old_head = list_;
Redirection* replaced_list_head =
AtomicOperations::CompareAndSwapPointer<Redirection>(&list_, old_head,
redirection);
ASSERT(old_head == replaced_list_head);
return redirection;
}
static Redirection* FromSvcInstruction(Instr* svc_instruction) {
char* addr_of_svc = reinterpret_cast<char*>(svc_instruction);
char* addr_of_redirection =
addr_of_svc - OFFSET_OF(Redirection, svc_instruction_);
return reinterpret_cast<Redirection*>(addr_of_redirection);
}
// Please note that this function is called by the signal handler of the
// profiling thread. It can therefore run at any point in time and is not
// allowed to hold any locks - which is precisely the reason why the list is
// prepend-only and a memory fence is used when writing the list head [list_]!
static uword FunctionForRedirect(uword address_of_svc) {
Redirection* current;
for (current = list_; current != NULL; current = current->next_) {
if (current->address_of_svc_instruction() == address_of_svc) {
return current->external_function_;
}
}
return 0;
}
private:
Redirection(uword external_function,
Simulator::CallKind call_kind,
int argument_count)
: external_function_(external_function),
call_kind_(call_kind),
argument_count_(argument_count),
svc_instruction_(Instr::kSimulatorRedirectInstruction),
next_(NULL) {}
uword external_function_;
Simulator::CallKind call_kind_;
int argument_count_;
uint32_t svc_instruction_;
Redirection* next_;
static Redirection* list_;
static Mutex* mutex_;
};
Redirection* Redirection::list_ = NULL;
Mutex* Redirection::mutex_ = new Mutex();
uword Simulator::RedirectExternalReference(uword function,
CallKind call_kind,
int argument_count) {
Redirection* redirection =
Redirection::Get(function, call_kind, argument_count);
return redirection->address_of_svc_instruction();
}
uword Simulator::FunctionForRedirect(uword redirect) {
return Redirection::FunctionForRedirect(redirect);
}
// Get the active Simulator for the current isolate.
Simulator* Simulator::Current() {
Simulator* simulator = Isolate::Current()->simulator();
if (simulator == NULL) {
simulator = new Simulator();
Isolate::Current()->set_simulator(simulator);
}
return simulator;
}
// Sets the register in the architecture state. It will also deal with updating
// Simulator internal state for special registers such as PC.
DART_FORCE_INLINE void Simulator::set_register(Register reg, int32_t value) {
ASSERT((reg >= 0) && (reg < kNumberOfCpuRegisters));
if (reg == PC) {
pc_modified_ = true;
}
registers_[reg] = value;
}
// Raw access to the PC register.
DART_FORCE_INLINE void Simulator::set_pc(int32_t value) {
pc_modified_ = true;
registers_[PC] = value;
}
// Accessors for VFP register state.
DART_FORCE_INLINE void Simulator::set_sregister(SRegister reg, float value) {
ASSERT(TargetCPUFeatures::vfp_supported());
ASSERT((reg >= 0) && (reg < kNumberOfSRegisters));
sregisters_[reg] = bit_cast<int32_t, float>(value);
}
DART_FORCE_INLINE float Simulator::get_sregister(SRegister reg) const {
ASSERT(TargetCPUFeatures::vfp_supported());
ASSERT((reg >= 0) && (reg < kNumberOfSRegisters));
return bit_cast<float, int32_t>(sregisters_[reg]);
}
DART_FORCE_INLINE void Simulator::set_dregister(DRegister reg, double value) {
ASSERT(TargetCPUFeatures::vfp_supported());
ASSERT((reg >= 0) && (reg < kNumberOfDRegisters));
dregisters_[reg] = bit_cast<int64_t, double>(value);
}
DART_FORCE_INLINE double Simulator::get_dregister(DRegister reg) const {
ASSERT(TargetCPUFeatures::vfp_supported());
ASSERT((reg >= 0) && (reg < kNumberOfDRegisters));
return bit_cast<double, int64_t>(dregisters_[reg]);
}
void Simulator::set_qregister(QRegister reg, const simd_value_t& value) {
ASSERT(TargetCPUFeatures::neon_supported());
ASSERT((reg >= 0) && (reg < kNumberOfQRegisters));
qregisters_[reg].data_[0] = value.data_[0];
qregisters_[reg].data_[1] = value.data_[1];
qregisters_[reg].data_[2] = value.data_[2];
qregisters_[reg].data_[3] = value.data_[3];
}
void Simulator::get_qregister(QRegister reg, simd_value_t* value) const {
ASSERT(TargetCPUFeatures::neon_supported());
// TODO(zra): Replace this test with an assert after we support
// 16 Q registers.
if ((reg >= 0) && (reg < kNumberOfQRegisters)) {
*value = qregisters_[reg];
}
}
void Simulator::set_sregister_bits(SRegister reg, int32_t value) {
ASSERT(TargetCPUFeatures::vfp_supported());
ASSERT((reg >= 0) && (reg < kNumberOfSRegisters));
sregisters_[reg] = value;
}
int32_t Simulator::get_sregister_bits(SRegister reg) const {
ASSERT(TargetCPUFeatures::vfp_supported());
ASSERT((reg >= 0) && (reg < kNumberOfSRegisters));
return sregisters_[reg];
}
void Simulator::set_dregister_bits(DRegister reg, int64_t value) {
ASSERT(TargetCPUFeatures::vfp_supported());
ASSERT((reg >= 0) && (reg < kNumberOfDRegisters));
dregisters_[reg] = value;
}
int64_t Simulator::get_dregister_bits(DRegister reg) const {
ASSERT(TargetCPUFeatures::vfp_supported());
ASSERT((reg >= 0) && (reg < kNumberOfDRegisters));
return dregisters_[reg];
}
void Simulator::HandleIllegalAccess(uword addr, Instr* instr) {
uword fault_pc = get_pc();
// The debugger will not be able to single step past this instruction, but
// it will be possible to disassemble the code and inspect registers.
char buffer[128];
snprintf(buffer, sizeof(buffer),
"illegal memory access at 0x%" Px ", pc=0x%" Px "\n", addr,
fault_pc);
SimulatorDebugger dbg(this);
dbg.Stop(instr, buffer);
// The debugger will return control in non-interactive mode.
FATAL("Cannot continue execution after illegal memory access.");
}
// Processor versions prior to ARMv7 could not do unaligned reads and writes.
// On some ARM platforms an interrupt is caused. On others it does a funky
// rotation thing. However, from version v7, unaligned access is supported.
// Note that simulator runs have the runtime system running directly on the host
// system and only generated code is executed in the simulator. Since the host
// is typically IA32 we will get the correct ARMv7-like behaviour on unaligned
// accesses, but we should actually not generate code accessing unaligned data,
// so we still want to know and abort if we encounter such code.
void Simulator::UnalignedAccess(const char* msg, uword addr, Instr* instr) {
// The debugger will not be able to single step past this instruction, but
// it will be possible to disassemble the code and inspect registers.
char buffer[64];
snprintf(buffer, sizeof(buffer), "unaligned %s at 0x%" Px ", pc=%p\n", msg,
addr, instr);
SimulatorDebugger dbg(this);
dbg.Stop(instr, buffer);
// The debugger will return control in non-interactive mode.
FATAL("Cannot continue execution after unaligned access.");
}
void Simulator::UnimplementedInstruction(Instr* instr) {
char buffer[64];
snprintf(buffer, sizeof(buffer), "Unimplemented instruction: pc=%p\n", instr);
SimulatorDebugger dbg(this);
dbg.Stop(instr, buffer);
FATAL("Cannot continue execution after unimplemented instruction.");
}
DART_FORCE_INLINE intptr_t Simulator::ReadW(uword addr, Instr* instr) {
if ((addr & 3) == 0) {
intptr_t* ptr = reinterpret_cast<intptr_t*>(addr);
return *ptr;
}
UnalignedAccess("read", addr, instr);
return 0;
}
DART_FORCE_INLINE void Simulator::WriteW(uword addr,
intptr_t value,
Instr* instr) {
if ((addr & 3) == 0) {
intptr_t* ptr = reinterpret_cast<intptr_t*>(addr);
*ptr = value;
return;
}
UnalignedAccess("write", addr, instr);
}
DART_FORCE_INLINE uint16_t Simulator::ReadHU(uword addr, Instr* instr) {
if ((addr & 1) == 0) {
uint16_t* ptr = reinterpret_cast<uint16_t*>(addr);
return *ptr;
}
UnalignedAccess("unsigned halfword read", addr, instr);
return 0;
}
DART_FORCE_INLINE int16_t Simulator::ReadH(uword addr, Instr* instr) {
if ((addr & 1) == 0) {
int16_t* ptr = reinterpret_cast<int16_t*>(addr);
return *ptr;
}
UnalignedAccess("signed halfword read", addr, instr);
return 0;
}
DART_FORCE_INLINE void Simulator::WriteH(uword addr,
uint16_t value,
Instr* instr) {
if ((addr & 1) == 0) {
uint16_t* ptr = reinterpret_cast<uint16_t*>(addr);
*ptr = value;
return;
}
UnalignedAccess("halfword write", addr, instr);
}
DART_FORCE_INLINE uint8_t Simulator::ReadBU(uword addr) {
uint8_t* ptr = reinterpret_cast<uint8_t*>(addr);
return *ptr;
}
DART_FORCE_INLINE int8_t Simulator::ReadB(uword addr) {
int8_t* ptr = reinterpret_cast<int8_t*>(addr);
return *ptr;
}
DART_FORCE_INLINE void Simulator::WriteB(uword addr, uint8_t value) {
uint8_t* ptr = reinterpret_cast<uint8_t*>(addr);
*ptr = value;
}
void Simulator::ClearExclusive() {
exclusive_access_addr_ = 0;
exclusive_access_value_ = 0;
}
intptr_t Simulator::ReadExclusiveW(uword addr, Instr* instr) {
exclusive_access_addr_ = addr;
exclusive_access_value_ = ReadW(addr, instr);
return exclusive_access_value_;
}
intptr_t Simulator::WriteExclusiveW(uword addr, intptr_t value, Instr* instr) {
// In a well-formed code store-exclusive instruction should always follow
// a corresponding load-exclusive instruction with the same address.
ASSERT((exclusive_access_addr_ == 0) || (exclusive_access_addr_ == addr));
if (exclusive_access_addr_ != addr) {
return 1; // Failure.
}
uword old_value = exclusive_access_value_;
ClearExclusive();
if (AtomicOperations::CompareAndSwapWord(reinterpret_cast<uword*>(addr),
old_value, value) == old_value) {
return 0; // Success.
}
return 1; // Failure.
}
bool Simulator::IsTracingExecution() const {
return icount_ > FLAG_trace_sim_after;
}
// Unsupported instructions use Format to print an error and stop execution.
void Simulator::Format(Instr* instr, const char* format) {
OS::PrintErr("Simulator found unsupported instruction:\n 0x%p: %s\n", instr,
format);
UNIMPLEMENTED();
}
// Checks if the current instruction should be executed based on its
// condition bits.
DART_FORCE_INLINE bool Simulator::ConditionallyExecute(Instr* instr) {
switch (instr->ConditionField()) {
case EQ:
return z_flag_;
case NE:
return !z_flag_;
case CS:
return c_flag_;
case CC:
return !c_flag_;
case MI:
return n_flag_;
case PL:
return !n_flag_;
case VS:
return v_flag_;
case VC:
return !v_flag_;
case HI:
return c_flag_ && !z_flag_;
case LS:
return !c_flag_ || z_flag_;
case GE:
return n_flag_ == v_flag_;
case LT:
return n_flag_ != v_flag_;
case GT:
return !z_flag_ && (n_flag_ == v_flag_);
case LE:
return z_flag_ || (n_flag_ != v_flag_);
case AL:
return true;
default:
UNREACHABLE();
}
return false;
}
// Calculate and set the Negative and Zero flags.
DART_FORCE_INLINE void Simulator::SetNZFlags(int32_t val) {
n_flag_ = (val < 0);
z_flag_ = (val == 0);
}
// Set the Carry flag.
DART_FORCE_INLINE void Simulator::SetCFlag(bool val) {
c_flag_ = val;
}
// Set the oVerflow flag.
DART_FORCE_INLINE void Simulator::SetVFlag(bool val) {
v_flag_ = val;
}
// Calculate C flag value for additions (and subtractions with adjusted args).
DART_FORCE_INLINE bool Simulator::CarryFrom(int32_t left,
int32_t right,
int32_t carry) {
uint64_t uleft = static_cast<uint32_t>(left);
uint64_t uright = static_cast<uint32_t>(right);
uint64_t ucarry = static_cast<uint32_t>(carry);
return ((uleft + uright + ucarry) >> 32) != 0;
}
// Calculate V flag value for additions (and subtractions with adjusted args).
DART_FORCE_INLINE bool Simulator::OverflowFrom(int32_t left,
int32_t right,
int32_t carry) {
int64_t result = static_cast<int64_t>(left) + right + carry;
return (result >> 31) != (result >> 32);
}
// Addressing Mode 1 - Data-processing operands:
// Get the value based on the shifter_operand with register.
int32_t Simulator::GetShiftRm(Instr* instr, bool* carry_out) {
Shift shift = instr->ShiftField();
int shift_amount = instr->ShiftAmountField();
int32_t result = get_register(instr->RmField());
if (instr->Bit(4) == 0) {
// by immediate
if ((shift == ROR) && (shift_amount == 0)) {
UnimplementedInstruction(instr);
} else if (((shift == LSR) || (shift == ASR)) && (shift_amount == 0)) {
shift_amount = 32;
}
switch (shift) {
case ASR: {
if (shift_amount == 0) {
if (result < 0) {
result = 0xffffffff;
*carry_out = true;
} else {
result = 0;
*carry_out = false;
}
} else {
result >>= (shift_amount - 1);
*carry_out = (result & 1) == 1;
result >>= 1;
}
break;
}
case LSL: {
if (shift_amount == 0) {
*carry_out = c_flag_;
} else {
result <<= (shift_amount - 1);
*carry_out = (result < 0);
result <<= 1;
}
break;
}
case LSR: {
if (shift_amount == 0) {
result = 0;
*carry_out = c_flag_;
} else {
uint32_t uresult = static_cast<uint32_t>(result);
uresult >>= (shift_amount - 1);
*carry_out = (uresult & 1) == 1;
uresult >>= 1;
result = static_cast<int32_t>(uresult);
}
break;
}
case ROR: {
UnimplementedInstruction(instr);
break;
}
default: {
UNREACHABLE();
break;
}
}
} else {
// by register
Register rs = instr->RsField();
shift_amount = get_register(rs) & 0xff;
switch (shift) {
case ASR: {
if (shift_amount == 0) {
*carry_out = c_flag_;
} else if (shift_amount < 32) {
result >>= (shift_amount - 1);
*carry_out = (result & 1) == 1;
result >>= 1;
} else {
ASSERT(shift_amount >= 32);
if (result < 0) {
*carry_out = true;
result = 0xffffffff;
} else {
*carry_out = false;
result = 0;
}
}
break;
}
case LSL: {
if (shift_amount == 0) {
*carry_out = c_flag_;
} else if (shift_amount < 32) {
result <<= (shift_amount - 1);
*carry_out = (result < 0);
result <<= 1;
} else if (shift_amount == 32) {
*carry_out = (result & 1) == 1;
result = 0;
} else {
ASSERT(shift_amount > 32);
*carry_out = false;
result = 0;
}
break;
}
case LSR: {
if (shift_amount == 0) {
*carry_out = c_flag_;
} else if (shift_amount < 32) {
uint32_t uresult = static_cast<uint32_t>(result);
uresult >>= (shift_amount - 1);
*carry_out = (uresult & 1) == 1;
uresult >>= 1;
result = static_cast<int32_t>(uresult);
} else if (shift_amount == 32) {
*carry_out = (result < 0);
result = 0;
} else {
*carry_out = false;
result = 0;
}
break;
}
case ROR: {
UnimplementedInstruction(instr);
break;
}
default: {
UNREACHABLE();
break;
}
}
}
return result;
}
// Addressing Mode 1 - Data-processing operands:
// Get the value based on the shifter_operand with immediate.
DART_FORCE_INLINE int32_t Simulator::GetImm(Instr* instr, bool* carry_out) {
int rotate = instr->RotateField() * 2;
int immed8 = instr->Immed8Field();
int imm = (immed8 >> rotate) | (immed8 << (32 - rotate));
*carry_out = (rotate == 0) ? c_flag_ : (imm < 0);
return imm;
}
// Addressing Mode 4 - Load and Store Multiple
void Simulator::HandleRList(Instr* instr, bool load) {
Register rn = instr->RnField();
int32_t rn_val = get_register(rn);
int rlist = instr->RlistField();
int num_regs = Utils::CountOneBits32(static_cast<uint32_t>(rlist));
uword address = 0;
uword end_address = 0;
switch (instr->PUField()) {
case 0: {
// Print("da");
address = rn_val - (num_regs * 4) + 4;
end_address = rn_val + 4;
rn_val = rn_val - (num_regs * 4);
break;
}
case 1: {
// Print("ia");
address = rn_val;
end_address = rn_val + (num_regs * 4);
rn_val = rn_val + (num_regs * 4);
break;
}
case 2: {
// Print("db");
address = rn_val - (num_regs * 4);
end_address = rn_val;
rn_val = address;
break;
}
case 3: {
// Print("ib");
address = rn_val + 4;
end_address = rn_val + (num_regs * 4) + 4;
rn_val = rn_val + (num_regs * 4);
break;
}
default: {
UNREACHABLE();
break;
}
}
if (IsIllegalAddress(address)) {
HandleIllegalAccess(address, instr);
} else {
if (instr->HasW()) {
set_register(rn, rn_val);
}
int reg = 0;
while (rlist != 0) {
if ((rlist & 1) != 0) {
if (load) {
set_register(static_cast<Register>(reg), ReadW(address, instr));
} else {
WriteW(address, get_register(static_cast<Register>(reg)), instr);
}
address += 4;
}
reg++;
rlist >>= 1;
}
ASSERT(end_address == address);
}
}
// Calls into the Dart runtime are based on this interface.
typedef void (*SimulatorRuntimeCall)(NativeArguments arguments);
// Calls to leaf Dart runtime functions are based on this interface.
typedef int32_t (*SimulatorLeafRuntimeCall)(int32_t r0,
int32_t r1,
int32_t r2,
int32_t r3,
int32_t r4);
// Calls to leaf float Dart runtime functions are based on this interface.
typedef double (*SimulatorLeafFloatRuntimeCall)(double d0, double d1);
// Calls to native Dart functions are based on this interface.
typedef void (*SimulatorBootstrapNativeCall)(NativeArguments* arguments);
typedef void (*SimulatorNativeCall)(NativeArguments* arguments, uword target);
void Simulator::SupervisorCall(Instr* instr) {
int svc = instr->SvcField();
switch (svc) {
case Instr::kSimulatorRedirectCode: {
SimulatorSetjmpBuffer buffer(this);
if (!setjmp(buffer.buffer_)) {
int32_t saved_lr = get_register(LR);
Redirection* redirection = Redirection::FromSvcInstruction(instr);
uword external = redirection->external_function();
if (IsTracingExecution()) {
THR_Print("Call to host function at 0x%" Pd "\n", external);
}
if (redirection->call_kind() == kRuntimeCall) {
NativeArguments arguments(NULL, 0, NULL, NULL);
ASSERT(sizeof(NativeArguments) == 4 * kWordSize);
arguments.thread_ = reinterpret_cast<Thread*>(get_register(R0));
arguments.argc_tag_ = get_register(R1);
arguments.argv_ = reinterpret_cast<RawObject**>(get_register(R2));
arguments.retval_ = reinterpret_cast<RawObject**>(get_register(R3));
SimulatorRuntimeCall target =
reinterpret_cast<SimulatorRuntimeCall>(external);
target(arguments);
set_register(R0, icount_); // Zap result register from void function.
set_register(R1, icount_);
} else if (redirection->call_kind() == kLeafRuntimeCall) {
ASSERT((0 <= redirection->argument_count()) &&
(redirection->argument_count() <= 5));
int32_t r0 = get_register(R0);
int32_t r1 = get_register(R1);
int32_t r2 = get_register(R2);
int32_t r3 = get_register(R3);
int32_t r4 = *reinterpret_cast<int32_t*>(get_register(SP));
SimulatorLeafRuntimeCall target =
reinterpret_cast<SimulatorLeafRuntimeCall>(external);
r0 = target(r0, r1, r2, r3, r4);
set_register(R0, r0); // Set returned result from function.
set_register(R1, icount_); // Zap unused result register.
} else if (redirection->call_kind() == kLeafFloatRuntimeCall) {
ASSERT((0 <= redirection->argument_count()) &&
(redirection->argument_count() <= 2));
SimulatorLeafFloatRuntimeCall target =
reinterpret_cast<SimulatorLeafFloatRuntimeCall>(external);
if (TargetCPUFeatures::hardfp_supported()) {
// If we're doing "hardfp", the double arguments are already in the
// floating point registers.
double d0 = get_dregister(D0);
double d1 = get_dregister(D1);
d0 = target(d0, d1);
set_dregister(D0, d0);
} else {
// If we're not doing "hardfp", we must be doing "soft" or "softfp",
// So take the double arguments from the integer registers.
uint32_t r0 = get_register(R0);
int32_t r1 = get_register(R1);
uint32_t r2 = get_register(R2);
int32_t r3 = get_register(R3);
int64_t a0 = Utils::LowHighTo64Bits(r0, r1);
int64_t a1 = Utils::LowHighTo64Bits(r2, r3);
double d0 = bit_cast<double, int64_t>(a0);
double d1 = bit_cast<double, int64_t>(a1);
d0 = target(d0, d1);
a0 = bit_cast<int64_t, double>(d0);
r0 = Utils::Low32Bits(a0);
r1 = Utils::High32Bits(a0);
set_register(R0, r0);
set_register(R1, r1);
}
} else if (redirection->call_kind() == kBootstrapNativeCall) {
ASSERT(redirection->argument_count() == 1);
NativeArguments* arguments;
arguments = reinterpret_cast<NativeArguments*>(get_register(R0));
SimulatorBootstrapNativeCall target =
reinterpret_cast<SimulatorBootstrapNativeCall>(external);
target(arguments);
set_register(R0, icount_); // Zap result register from void function.
} else {
ASSERT(redirection->call_kind() == kNativeCall);
NativeArguments* arguments;
arguments = reinterpret_cast<NativeArguments*>(get_register(R0));
uword target_func = get_register(R1);
SimulatorNativeCall target =
reinterpret_cast<SimulatorNativeCall>(external);
target(arguments, target_func);
set_register(R0, icount_); // Zap result register from void function.
set_register(R1, icount_);
}
// Zap caller-saved registers, since the actual runtime call could have
// used them.
set_register(R2, icount_);
set_register(R3, icount_);
set_register(IP, icount_);
set_register(LR, icount_);
if (TargetCPUFeatures::vfp_supported()) {
double zap_dvalue = static_cast<double>(icount_);
// Do not zap D0, as it may contain a float result.
for (int i = D1; i <= D7; i++) {
set_dregister(static_cast<DRegister>(i), zap_dvalue);
}
// The above loop also zaps overlapping registers S2-S15.
// Registers D8-D15 (overlapping with S16-S31) are preserved.
#if defined(VFPv3_D32)
for (int i = D16; i <= D31; i++) {
set_dregister(static_cast<DRegister>(i), zap_dvalue);
}
#endif
}
// Return.
set_pc(saved_lr);
} else {
// Coming via long jump from a throw. Continue to exception handler.
}
break;
}
case Instr::kSimulatorBreakCode: {
SimulatorDebugger dbg(this);
dbg.Stop(instr, "breakpoint");
break;
}
default: {
UNREACHABLE();
break;
}
}
}
// Handle execution based on instruction types.
// Instruction types 0 and 1 are both rolled into one function because they
// only differ in the handling of the shifter_operand.
DART_FORCE_INLINE void Simulator::DecodeType01(Instr* instr) {
if (!instr->IsDataProcessing()) {
// miscellaneous, multiply, sync primitives, extra loads and stores.
if (instr->IsMiscellaneous()) {
switch (instr->Bits(4, 3)) {
case 1: {
if (instr->Bits(21, 2) == 0x3) {
// Format(instr, "clz'cond 'rd, 'rm");
Register rm = instr->RmField();
Register rd = instr->RdField();
int32_t rm_val = get_register(rm);
int32_t rd_val = 0;
if (rm_val != 0) {
while (rm_val > 0) {
rd_val++;
rm_val <<= 1;
}
} else {
rd_val = 32;
}
set_register(rd, rd_val);
} else {
ASSERT(instr->Bits(21, 2) == 0x1);
// Format(instr, "bx'cond 'rm");
Register rm = instr->RmField();
int32_t rm_val = get_register(rm);
set_pc(rm_val);
}
break;
}
case 3: {
ASSERT(instr->Bits(21, 2) == 0x1);
// Format(instr, "blx'cond 'rm");
Register rm = instr->RmField();
int32_t rm_val = get_register(rm);
intptr_t pc = get_pc();
set_register(LR, pc + Instr::kInstrSize);
set_pc(rm_val);
break;
}
case 7: {
if ((instr->Bits(21, 2) == 0x1) && (instr->ConditionField() == AL)) {
// Format(instr, "bkpt #'imm12_4");
SimulatorDebugger dbg(this);
int32_t imm = instr->BkptField();
char buffer[32];
snprintf(buffer, sizeof(buffer), "bkpt #0x%x", imm);
set_pc(get_pc() + Instr::kInstrSize);
dbg.Stop(instr, buffer);
} else {
// Format(instr, "smc'cond");
UnimplementedInstruction(instr);
}
break;
}
default: {
UnimplementedInstruction(instr);
break;
}
}
} else if (instr->IsMultiplyOrSyncPrimitive()) {
if (instr->Bit(24) == 0) {
// multiply instructions.
Register rn = instr->RnField();
Register rd = instr->RdField();
Register rs = instr->RsField();
Register rm = instr->RmField();
int32_t rm_val = get_register(rm);
int32_t rs_val = get_register(rs);
int32_t rd_val = 0;
switch (instr->Bits(21, 3)) {
case 1:
// Registers rd, rn, rm, ra are encoded as rn, rm, rs, rd.
// Format(instr, "mla'cond's 'rn, 'rm, 'rs, 'rd");
case 3: {
// Registers rd, rn, rm, ra are encoded as rn, rm, rs, rd.
// Format(instr, "mls'cond's 'rn, 'rm, 'rs, 'rd");
rd_val = get_register(rd);
FALL_THROUGH;
}
case 0: {
// Registers rd, rn, rm are encoded as rn, rm, rs.
// Format(instr, "mul'cond's 'rn, 'rm, 'rs");
int32_t alu_out = rm_val * rs_val;
if (instr->Bits(21, 3) == 3) { // mls
if (TargetCPUFeatures::arm_version() != ARMv7) {
UnimplementedInstruction(instr);
break;
}
alu_out = -alu_out;
}
alu_out += rd_val;
set_register(rn, alu_out);
if (instr->HasS()) {
SetNZFlags(alu_out);
}
break;
}
case 4:
// Registers rd_lo, rd_hi, rn, rm are encoded as rd, rn, rm, rs.
// Format(instr, "umull'cond's 'rd, 'rn, 'rm, 'rs");
case 6: {
// Registers rd_lo, rd_hi, rn, rm are encoded as rd, rn, rm, rs.
// Format(instr, "smull'cond's 'rd, 'rn, 'rm, 'rs");
int64_t result;
if (instr->Bits(21, 3) == 4) { // umull
uint64_t left_op = static_cast<uint32_t>(rm_val);
uint64_t right_op = static_cast<uint32_t>(rs_val);
result = left_op * right_op; // Unsigned multiplication.
} else { // smull
int64_t left_op = static_cast<int32_t>(rm_val);
int64_t right_op = static_cast<int32_t>(rs_val);
result = left_op * right_op; // Signed multiplication.
}
int32_t hi_res = Utils::High32Bits(result);
int32_t lo_res = Utils::Low32Bits(result);
set_register(rd, lo_res);
set_register(rn, hi_res);
if (instr->HasS()) {
if (lo_res != 0) {
// Collapse bits 0..31 into bit 32 so that 32-bit Z check works.
hi_res |= 1;
}
ASSERT((result == 0) == (hi_res == 0)); // Z bit
ASSERT(((result & (1LL << 63)) != 0) == (hi_res < 0)); // N bit
SetNZFlags(hi_res);
}
break;
}
case 2:
// Registers rd_lo, rd_hi, rn, rm are encoded as rd, rn, rm, rs.
// Format(instr, "umaal'cond's 'rd, 'rn, 'rm, 'rs");
if (TargetCPUFeatures::arm_version() == ARMv5TE) {
// umaal is only in ARMv6 and above.
UnimplementedInstruction(instr);
}
FALL_THROUGH;
case 5:
// Registers rd_lo, rd_hi, rn, rm are encoded as rd, rn, rm, rs.
// Format(instr, "umlal'cond's 'rd, 'rn, 'rm, 'rs");
case 7: {
// Registers rd_lo, rd_hi, rn, rm are encoded as rd, rn, rm, rs.
// Format(instr, "smlal'cond's 'rd, 'rn, 'rm, 'rs");
int32_t rd_lo_val = get_register(rd);
int32_t rd_hi_val = get_register(rn);
uint32_t accum_lo = static_cast<uint32_t>(rd_lo_val);
int32_t accum_hi = static_cast<int32_t>(rd_hi_val);
int64_t accum = Utils::LowHighTo64Bits(accum_lo, accum_hi);
int64_t result;
if (instr->Bits(21, 3) == 5) { // umlal
uint64_t left_op = static_cast<uint32_t>(rm_val);
uint64_t right_op = static_cast<uint32_t>(rs_val);
result = accum + left_op * right_op; // Unsigned multiplication.
} else if (instr->Bits(21, 3) == 7) { // smlal
int64_t left_op = static_cast<int32_t>(rm_val);
int64_t right_op = static_cast<int32_t>(rs_val);
result = accum + left_op * right_op; // Signed multiplication.
} else {
ASSERT(instr->Bits(21, 3) == 2); // umaal
ASSERT(!instr->HasS());
uint64_t left_op = static_cast<uint32_t>(rm_val);
uint64_t right_op = static_cast<uint32_t>(rs_val);
result = left_op * right_op + // Unsigned multiplication.
static_cast<uint32_t>(rd_lo_val) +
static_cast<uint32_t>(rd_hi_val);
}
int32_t hi_res = Utils::High32Bits(result);
int32_t lo_res = Utils::Low32Bits(result);
set_register(rd, lo_res);
set_register(rn, hi_res);
if (instr->HasS()) {
if (lo_res != 0) {
// Collapse bits 0..31 into bit 32 so that 32-bit Z check works.
hi_res |= 1;
}
ASSERT((result == 0) == (hi_res == 0)); // Z bit
ASSERT(((result & (1LL << 63)) != 0) == (hi_res < 0)); // N bit
SetNZFlags(hi_res);
}
break;
}
default: {
UnimplementedInstruction(instr);
break;
}
}
} else {
if (TargetCPUFeatures::arm_version() == ARMv5TE) {
UnimplementedInstruction(instr);
return;
}
// synchronization primitives
Register rd = instr->RdField();
Register rn = instr->RnField();
uword addr = get_register(rn);
switch (instr->Bits(20, 4)) {
case 8: {
// Format(instr, "strex'cond 'rd, 'rm, ['rn]");
if (IsIllegalAddress(addr)) {
HandleIllegalAccess(addr, instr);
} else {
Register rm = instr->RmField();
set_register(rd, WriteExclusiveW(addr, get_register(rm), instr));
}
break;
}
case 9: {
// Format(instr, "ldrex'cond 'rd, ['rn]");
if (IsIllegalAddress(addr)) {
HandleIllegalAccess(addr, instr);
} else {
set_register(rd, ReadExclusiveW(addr, instr));
}
break;
}
default: {
UnimplementedInstruction(instr);
break;
}
}
}
} else if (instr->Bit(25) == 1) {
// 16-bit immediate loads, msr (immediate), and hints
switch (instr->Bits(20, 5)) {
case 16:
case 20: {
if (TargetCPUFeatures::arm_version() == ARMv7) {
uint16_t imm16 = instr->MovwField();
Register rd = instr->RdField();
if (instr->Bit(22) == 0) {
// Format(instr, "movw'cond 'rd, #'imm4_12");
set_register(rd, imm16);
} else {
// Format(instr, "movt'cond 'rd, #'imm4_12");
set_register(rd, (get_register(rd) & 0xffff) | (imm16 << 16));
}
} else {
UnimplementedInstruction(instr);
}
break;
}
case 18: {
if ((instr->Bits(16, 4) == 0) && (instr->Bits(0, 8) == 0)) {
// Format(instr, "nop'cond");
} else {
UnimplementedInstruction(instr);
}
break;
}
default: {
UnimplementedInstruction(instr);
break;
}
}
} else {
// extra load/store instructions
Register rd = instr->RdField();
Register rn = instr->RnField();
int32_t rn_val = get_register(rn);
uword addr = 0;
bool write_back = false;
if (instr->Bit(22) == 0) {
Register rm = instr->RmField();
int32_t rm_val = get_register(rm);
switch (instr->PUField()) {
case 0: {
// Format(instr, "'memop'cond'x 'rd2, ['rn], -'rm");
ASSERT(!instr->HasW());
addr = rn_val;
rn_val -= rm_val;
write_back = true;
break;
}
case 1: {
// Format(instr, "'memop'cond'x 'rd2, ['rn], +'rm");
ASSERT(!instr->HasW());
addr = rn_val;
rn_val += rm_val;
write_back = true;
break;
}
case 2: {
// Format(instr, "'memop'cond'x 'rd2, ['rn, -'rm]'w");
rn_val -= rm_val;
addr = rn_val;
write_back = instr->HasW();
break;
}
case 3: {
// Format(instr, "'memop'cond'x 'rd2, ['rn, +'rm]'w");
rn_val += rm_val;
addr = rn_val;
write_back = instr->HasW();
break;
}
default: {
// The PU field is a 2-bit field.
UNREACHABLE();
break;
}
}
} else {
int32_t imm_val = (instr->ImmedHField() << 4) | instr->ImmedLField();
switch (instr->PUField()) {
case 0: {
// Format(instr, "'memop'cond'x 'rd2, ['rn], #-'off8");
ASSERT(!instr->HasW());
addr = rn_val;
rn_val -= imm_val;
write_back = true;
break;
}
case 1: {
// Format(instr, "'memop'cond'x 'rd2, ['rn], #+'off8");
ASSERT(!instr->HasW());
addr = rn_val;
rn_val += imm_val;
write_back = true;
break;
}
case 2: {
// Format(instr, "'memop'cond'x 'rd2, ['rn, #-'off8]'w");
rn_val -= imm_val;
addr = rn_val;
write_back = instr->HasW();
break;
}
case 3: {
// Format(instr, "'memop'cond'x 'rd2, ['rn, #+'off8]'w");
rn_val += imm_val;
addr = rn_val;
write_back = instr->HasW();
break;
}
default: {
// The PU field is a 2-bit field.
UNREACHABLE();
break;
}
}
}
if (IsIllegalAddress(addr)) {
HandleIllegalAccess(addr, instr);
} else {
if (write_back) {
ASSERT(rd != rn); // Unpredictable.
set_register(rn, rn_val);
}
if (!instr->HasSign()) {
if (instr->HasL()) {
uint16_t val = ReadHU(addr, instr);
set_register(rd, val);
} else {
uint16_t val = get_register(rd);
WriteH(addr, val, instr);
}
} else if (instr->HasL()) {
if (instr->HasH()) {
int16_t val = ReadH(addr, instr);
set_register(rd, val);
} else {
int8_t val = ReadB(addr);
set_register(rd, val);
}
} else if ((rd & 1) == 0) {
Register rd1 = static_cast<Register>(rd | 1);
ASSERT(rd1 < kNumberOfCpuRegisters);
if (instr->HasH()) {
int32_t val_low = get_register(rd);
int32_t val_high = get_register(rd1);
WriteW(addr, val_low, instr);
WriteW(addr + 4, val_high, instr);
} else {
int32_t val_low = ReadW(addr, instr);
int32_t val_high = ReadW(addr + 4, instr);
set_register(rd, val_low);
set_register(rd1, val_high);
}
} else {
UnimplementedInstruction(instr);
}
}
}
} else {
Register rd = instr->RdField();
Register rn = instr->RnField();
int32_t rn_val = get_register(rn);
int32_t shifter_operand = 0;
bool shifter_carry_out = 0;
if (instr->TypeField() == 0) {
shifter_operand = GetShiftRm(instr, &shifter_carry_out);
} else {
ASSERT(instr->TypeField() == 1);
shifter_operand = GetImm(instr, &shifter_carry_out);
}
int32_t carry_in;
int32_t alu_out;
switch (instr->OpcodeField()) {
case AND: {
// Format(instr, "and'cond's 'rd, 'rn, 'shift_rm");
// Format(instr, "and'cond's 'rd, 'rn, 'imm");
alu_out = rn_val & shifter_operand;
set_register(rd, alu_out);
if (instr->HasS()) {
SetNZFlags(alu_out);
SetCFlag(shifter_carry_out);
}
break;
}
case EOR: {
// Format(instr, "eor'cond's 'rd, 'rn, 'shift_rm");
// Format(instr, "eor'cond's 'rd, 'rn, 'imm");
alu_out = rn_val ^ shifter_operand;
set_register(rd, alu_out);
if (instr->HasS()) {
SetNZFlags(alu_out);
SetCFlag(shifter_carry_out);
}
break;
}
case SUB: {
// Format(instr, "sub'cond's 'rd, 'rn, 'shift_rm");
// Format(instr, "sub'cond's 'rd, 'rn, 'imm");
alu_out = rn_val - shifter_operand;
set_register(rd, alu_out);
if (instr->HasS()) {
SetNZFlags(alu_out);
SetCFlag(CarryFrom(rn_val, ~shifter_operand, 1));
SetVFlag(OverflowFrom(rn_val, ~shifter_operand, 1));
}
break;
}
case RSB: {
// Format(instr, "rsb'cond's 'rd, 'rn, 'shift_rm");
// Format(instr, "rsb'cond's 'rd, 'rn, 'imm");
alu_out = shifter_operand - rn_val;
set_register(rd, alu_out);
if (instr->HasS()) {
SetNZFlags(alu_out);
SetCFlag(CarryFrom(shifter_operand, ~rn_val, 1));
SetVFlag(OverflowFrom(shifter_operand, ~rn_val, 1));
}
break;
}
case ADD: {
// Format(instr, "add'cond's 'rd, 'rn, 'shift_rm");
// Format(instr, "add'cond's 'rd, 'rn, 'imm");
alu_out = rn_val + shifter_operand;
set_register(rd, alu_out);
if (instr->HasS()) {
SetNZFlags(alu_out);
SetCFlag(CarryFrom(rn_val, shifter_operand, 0));
SetVFlag(OverflowFrom(rn_val, shifter_operand, 0));
}
break;
}
case ADC: {
// Format(instr, "adc'cond's 'rd, 'rn, 'shift_rm");
// Format(instr, "adc'cond's 'rd, 'rn, 'imm");
carry_in = c_flag_ ? 1 : 0;
alu_out = rn_val + shifter_operand + carry_in;
set_register(rd, alu_out);
if (instr->HasS()) {
SetNZFlags(alu_out);
SetCFlag(CarryFrom(rn_val, shifter_operand, carry_in));
SetVFlag(OverflowFrom(rn_val, shifter_operand, carry_in));
}
break;
}
case SBC: {
// Format(instr, "sbc'cond's 'rd, 'rn, 'shift_rm");
// Format(instr, "sbc'cond's 'rd, 'rn, 'imm");
carry_in = c_flag_ ? 1 : 0;
alu_out = rn_val + ~shifter_operand + carry_in;
set_register(rd, alu_out);
if (instr->HasS()) {
SetNZFlags(alu_out);
SetCFlag(CarryFrom(rn_val, ~shifter_operand, carry_in));
SetVFlag(OverflowFrom(rn_val, ~shifter_operand, carry_in));
}
break;
}
case RSC: {
// Format(instr, "rsc'cond's 'rd, 'rn, 'shift_rm");
// Format(instr, "rsc'cond's 'rd, 'rn, 'imm");
carry_in = c_flag_ ? 1 : 0;
alu_out = shifter_operand + ~rn_val + carry_in;
set_register(rd, alu_out);
if (instr->HasS()) {
SetNZFlags(alu_out);
SetCFlag(CarryFrom(shifter_operand, ~rn_val, carry_in));
SetVFlag(OverflowFrom(shifter_operand, ~rn_val, carry_in));
}
break;
}
case TST: {
if (instr->HasS()) {
// Format(instr, "tst'cond 'rn, 'shift_rm");
// Format(instr, "tst'cond 'rn, 'imm");
alu_out = rn_val & shifter_operand;
SetNZFlags(alu_out);
SetCFlag(shifter_carry_out);
} else {
UnimplementedInstruction(instr);
}
break;
}
case TEQ: {
if (instr->HasS()) {
// Format(instr, "teq'cond 'rn, 'shift_rm");
// Format(instr, "teq'cond 'rn, 'imm");
alu_out = rn_val ^ shifter_operand;
SetNZFlags(alu_out);
SetCFlag(shifter_carry_out);
} else {
UnimplementedInstruction(instr);
}
break;
}
case CMP: {
if (instr->HasS()) {
// Format(instr, "cmp'cond 'rn, 'shift_rm");
// Format(instr, "cmp'cond 'rn, 'imm");
alu_out = rn_val - shifter_operand;
SetNZFlags(alu_out);
SetCFlag(CarryFrom(rn_val, ~shifter_operand, 1));
SetVFlag(OverflowFrom(rn_val, ~shifter_operand, 1));
} else {
UnimplementedInstruction(instr);
}
break;
}
case CMN: {
if (instr->HasS()) {
// Format(instr, "cmn'cond 'rn, 'shift_rm");
// Format(instr, "cmn'cond 'rn, 'imm");
alu_out = rn_val + shifter_operand;
SetNZFlags(alu_out);
SetCFlag(CarryFrom(rn_val, shifter_operand, 0));
SetVFlag(OverflowFrom(rn_val, shifter_operand, 0));
} else {
UnimplementedInstruction(instr);
}
break;
}
case ORR: {
// Format(instr, "orr'cond's 'rd, 'rn, 'shift_rm");
// Format(instr, "orr'cond's 'rd, 'rn, 'imm");
alu_out = rn_val | shifter_operand;
set_register(rd, alu_out);
if (instr->HasS()) {
SetNZFlags(alu_out);
SetCFlag(shifter_carry_out);
}
break;
}
case MOV: {
// Format(instr, "mov'cond's 'rd, 'shift_rm");
// Format(instr, "mov'cond's 'rd, 'imm");
alu_out = shifter_operand;
set_register(rd, alu_out);
if (instr->HasS()) {
SetNZFlags(alu_out);
SetCFlag(shifter_carry_out);
}
break;
}
case BIC: {
// Format(instr, "bic'cond's 'rd, 'rn, 'shift_rm");
// Format(instr, "bic'cond's 'rd, 'rn, 'imm");
alu_out = rn_val & ~shifter_operand;
set_register(rd, alu_out);
if (instr->HasS()) {
SetNZFlags(alu_out);
SetCFlag(shifter_carry_out);
}
break;
}
case MVN: {
// Format(instr, "mvn'cond's 'rd, 'shift_rm");
// Format(instr, "mvn'cond's 'rd, 'imm");
alu_out = ~shifter_operand;
set_register(rd, alu_out);
if (instr->HasS()) {
SetNZFlags(alu_out);
SetCFlag(shifter_carry_out);
}
break;
}
default: {
UNREACHABLE();
break;
}
}
}
}
DART_FORCE_INLINE void Simulator::DecodeType2(Instr* instr) {
Register rd = instr->RdField();
Register rn = instr->RnField();
int32_t rn_val = get_register(rn);
int32_t im_val = instr->Offset12Field();
uword addr = 0;
bool write_back = false;
switch (instr->PUField()) {
case 0: {
// Format(instr, "'memop'cond'b 'rd, ['rn], #-'off12");
ASSERT(!instr->HasW());
addr = rn_val;
rn_val -= im_val;
write_back = true;
break;
}
case 1: {
// Format(instr, "'memop'cond'b 'rd, ['rn], #+'off12");
ASSERT(!instr->HasW());
addr = rn_val;
rn_val += im_val;
write_back = true;
break;
}
case 2: {
// Format(instr, "'memop'cond'b 'rd, ['rn, #-'off12]'w");
rn_val -= im_val;
addr = rn_val;
write_back = instr->HasW();
break;
}
case 3: {
// Format(instr, "'memop'cond'b 'rd, ['rn, #+'off12]'w");
rn_val += im_val;
addr = rn_val;
write_back = instr->HasW();
break;
}
default: {
UNREACHABLE();
break;
}
}
if (IsIllegalAddress(addr)) {
HandleIllegalAccess(addr, instr);
} else {
if (write_back) {
ASSERT(rd != rn); // Unpredictable.
set_register(rn, rn_val);
}
if (instr->HasB()) {
if (instr->HasL()) {
unsigned char val = ReadBU(addr);
set_register(rd, val);
} else {
unsigned char val = get_register(rd);
WriteB(addr, val);
}
} else {
if (instr->HasL()) {
set_register(rd, ReadW(addr, instr));
} else {
WriteW(addr, get_register(rd), instr);
}
}
}
}
void Simulator::DoDivision(Instr* instr) {
const Register rd = instr->DivRdField();
const Register rn = instr->DivRnField();
const Register rm = instr->DivRmField();
if (!TargetCPUFeatures::integer_division_supported()) {
UnimplementedInstruction(instr);
return;
}
// ARMv7-a does not trap on divide-by-zero. The destination register is just
// set to 0.
if (get_register(rm) == 0) {
set_register(rd, 0);
return;
}
if (instr->Bit(21) == 1) {
// unsigned division.
uint32_t rn_val = static_cast<uint32_t>(get_register(rn));
uint32_t rm_val = static_cast<uint32_t>(get_register(rm));
uint32_t result = rn_val / rm_val;
set_register(rd, static_cast<int32_t>(result));
} else {
// signed division.
int32_t rn_val = get_register(rn);
int32_t rm_val = get_register(rm);
int32_t result;
if ((rn_val == static_cast<int32_t>(0x80000000)) &&
(rm_val == static_cast<int32_t>(0xffffffff))) {
result = 0x80000000;
} else {
result = rn_val / rm_val;
}
set_register(rd, result);
}
}
void Simulator::DecodeType3(Instr* instr) {
if (instr->IsDivision()) {
DoDivision(instr);
return;
}
Register rd = instr->RdField();
Register rn = instr->RnField();
int32_t rn_val = get_register(rn);
bool shifter_carry_out = 0;
int32_t shifter_operand = GetShiftRm(instr, &shifter_carry_out);
uword addr = 0;
bool write_back = false;
switch (instr->PUField()) {
case 0: {
// Format(instr, "'memop'cond'b 'rd, ['rn], -'shift_rm");
ASSERT(!instr->HasW());
addr = rn_val;
rn_val -= shifter_operand;
write_back = true;
break;
}
case 1: {
// Format(instr, "'memop'cond'b 'rd, ['rn], +'shift_rm");
ASSERT(!instr->HasW());
addr = rn_val;
rn_val += shifter_operand;
write_back = true;
break;
}
case 2: {
// Format(instr, "'memop'cond'b 'rd, ['rn, -'shift_rm]'w");
rn_val -= shifter_operand;
addr = rn_val;
write_back = instr->HasW();
break;
}
case 3: {
// Format(instr, "'memop'cond'b 'rd, ['rn, +'shift_rm]'w");
rn_val += shifter_operand;
addr = rn_val;
write_back = instr->HasW();
break;
}
default: {
UNREACHABLE();
break;
}
}
if (IsIllegalAddress(addr)) {
HandleIllegalAccess(addr, instr);
} else {
if (write_back) {
ASSERT(rd != rn); // Unpredictable.
set_register(rn, rn_val);
}
if (instr->HasB()) {
if (instr->HasL()) {
unsigned char val = ReadBU(addr);
set_register(rd, val);
} else {
unsigned char val = get_register(rd);
WriteB(addr, val);
}
} else {
if (instr->HasL()) {
set_register(rd, ReadW(addr, instr));
} else {
WriteW(addr, get_register(rd), instr);
}
}
}
}
void Simulator::DecodeType4(Instr* instr) {
ASSERT(instr->Bit(22) == 0); // only allowed to be set in privileged mode
if (instr->HasL()) {
// Format(instr, "ldm'cond'pu 'rn'w, 'rlist");
HandleRList(instr, true);
} else {
// Format(instr, "stm'cond'pu 'rn'w, 'rlist");
HandleRList(instr, false);
}
}
void Simulator::DecodeType5(Instr* instr) {
// Format(instr, "b'l'cond 'target");
int off = (instr->SImmed24Field() << 2) + 8;
intptr_t pc = get_pc();
if (instr->HasLink()) {
set_register(LR, pc + Instr::kInstrSize);
}
set_pc(pc + off);
}
void Simulator::DecodeType6(Instr* instr) {
if (instr->IsVFPDoubleTransfer()) {
Register rd = instr->RdField();
Register rn = instr->RnField();
if (instr->Bit(8) == 0) {
SRegister sm = instr->SmField();
SRegister sm1 = static_cast<SRegister>(sm + 1);
ASSERT(sm1 < kNumberOfSRegisters);
if (instr->Bit(20) == 1) {
// Format(instr, "vmovrrs'cond 'rd, 'rn, {'sm', 'sm1}");
set_register(rd, get_sregister_bits(sm));
set_register(rn, get_sregister_bits(sm1));
} else {
// Format(instr, "vmovsrr'cond {'sm, 'sm1}, 'rd', 'rn");
set_sregister_bits(sm, get_register(rd));
set_sregister_bits(sm1, get_register(rn));
}
} else {
DRegister dm = instr->DmField();
if (instr->Bit(20) == 1) {
// Format(instr, "vmovrrd'cond 'rd, 'rn, 'dm");
int64_t dm_val = get_dregister_bits(dm);
set_register(rd, Utils::Low32Bits(dm_val));
set_register(rn, Utils::High32Bits(dm_val));
} else {
// Format(instr, "vmovdrr'cond 'dm, 'rd, 'rn");
int64_t dm_val =
Utils::LowHighTo64Bits(get_register(rd), get_register(rn));
set_dregister_bits(dm, dm_val);
}
}
} else if (instr->IsVFPLoadStore()) {
Register rn = instr->RnField();
int32_t addr = get_register(rn);
int32_t imm_val = instr->Bits(0, 8) << 2;
if (instr->Bit(23) == 1) {
addr += imm_val;
} else {
addr -= imm_val;
}
if (IsIllegalAddress(addr)) {
HandleIllegalAccess(addr, instr);
} else {
if (instr->Bit(8) == 0) {
SRegister sd = instr->SdField();
if (instr->Bit(20) == 1) { // vldrs
// Format(instr, "vldrs'cond 'sd, ['rn, #+'off10]");
// Format(instr, "vldrs'cond 'sd, ['rn, #-'off10]");
set_sregister_bits(sd, ReadW(addr, instr));
} else { // vstrs
// Format(instr, "vstrs'cond 'sd, ['rn, #+'off10]");
// Format(instr, "vstrs'cond 'sd, ['rn, #-'off10]");
WriteW(addr, get_sregister_bits(sd), instr);
}
} else {
DRegister dd = instr->DdField();
if (instr->Bit(20) == 1) { // vldrd
// Format(instr, "vldrd'cond 'dd, ['rn, #+'off10]");
// Format(instr, "vldrd'cond 'dd, ['rn, #-'off10]");
int64_t dd_val = Utils::LowHighTo64Bits(ReadW(addr, instr),
ReadW(addr + 4, instr));
set_dregister_bits(dd, dd_val);
} else { // vstrd
// Format(instr, "vstrd'cond 'dd, ['rn, #+'off10]");
// Format(instr, "vstrd'cond 'dd, ['rn, #-'off10]");
int64_t dd_val = get_dregister_bits(dd);
WriteW(addr, Utils::Low32Bits(dd_val), instr);
WriteW(addr + 4, Utils::High32Bits(dd_val), instr);
}
}
}
} else if (instr->IsVFPMultipleLoadStore()) {
Register rn = instr->RnField();
int32_t addr = get_register(rn);
int32_t imm_val = instr->Bits(0, 8);
if (instr->Bit(23) == 0) {
addr -= (imm_val << 2);
}
if (instr->HasW()) {
if (instr->Bit(23) == 1) {
set_register(rn, addr + (imm_val << 2));
} else {
set_register(rn, addr); // already subtracted from addr
}
}
if (IsIllegalAddress(addr)) {
HandleIllegalAccess(addr, instr);
} else {
if (instr->Bit(8) == 0) {
int32_t regs_cnt = imm_val;
int32_t start = instr->Bit(22) | (instr->Bits(12, 4) << 1);
for (int i = start; i < start + regs_cnt; i++) {
SRegister sd = static_cast<SRegister>(i);
if (instr->Bit(20) == 1) {
// Format(instr, "vldms'cond'pu 'rn'w, 'slist");
set_sregister_bits(sd, ReadW(addr, instr));
} else {
// Format(instr, "vstms'cond'pu 'rn'w, 'slist");
WriteW(addr, get_sregister_bits(sd), instr);
}
addr += 4;
}
} else {
int32_t regs_cnt = imm_val >> 1;
int32_t start = (instr->Bit(22) << 4) | instr->Bits(12, 4);
if ((regs_cnt <= 16) && (start + regs_cnt <= kNumberOfDRegisters)) {
for (int i = start; i < start + regs_cnt; i++) {
DRegister dd = static_cast<DRegister>(i);
if (instr->Bit(20) == 1) {
// Format(instr, "vldmd'cond'pu 'rn'w, 'dlist");
int64_t dd_val = Utils::LowHighTo64Bits(ReadW(addr, instr),
ReadW(addr + 4, instr));
set_dregister_bits(dd, dd_val);
} else {
// Format(instr, "vstmd'cond'pu 'rn'w, 'dlist");
int64_t dd_val = get_dregister_bits(dd);
WriteW(addr, Utils::Low32Bits(dd_val), instr);
WriteW(addr + 4, Utils::High32Bits(dd_val), instr);
}
addr += 8;
}
} else {
UnimplementedInstruction(instr);
}
}
}
} else {
UnimplementedInstruction(instr);
}
}
void Simulator::DecodeType7(Instr* instr) {
if (instr->Bit(24) == 1) {
// Format(instr, "svc #'svc");
SupervisorCall(instr);
} else if (instr->IsVFPDataProcessingOrSingleTransfer()) {
if (instr->Bit(4) == 0) {
// VFP Data Processing
SRegister sd;
SRegister sn;
SRegister sm;
DRegister dd;
DRegister dn;
DRegister dm;
if (instr->Bit(8) == 0) {
sd = instr->SdField();
sn = instr->SnField();
sm = instr->SmField();
dd = kNoDRegister;
dn = kNoDRegister;
dm = kNoDRegister;
} else {
sd = kNoSRegister;
sn = kNoSRegister;
sm = kNoSRegister;
dd = instr->DdField();
dn = instr->DnField();
dm = instr->DmField();
}
switch (instr->Bits(20, 4) & 0xb) {
case 1: // vnmla, vnmls, vnmul
default: {
UnimplementedInstruction(instr);
break;
}
case 0: { // vmla, vmls floating-point
if (instr->Bit(8) == 0) {
float addend = get_sregister(sn) * get_sregister(sm);
float sd_val = get_sregister(sd);
if (instr->Bit(6) == 0) {
// Format(instr, "vmlas'cond 'sd, 'sn, 'sm");
} else {
// Format(instr, "vmlss'cond 'sd, 'sn, 'sm");