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Unified Diff: src/arm/simulator-arm.cc

Issue 92068: Move backend specific files to separate directories. (Closed)
Patch Set: Added CPPPATH flag and made all includes use same base path. Created 11 years, 8 months ago
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Index: src/arm/simulator-arm.cc
diff --git a/src/arm/simulator-arm.cc b/src/arm/simulator-arm.cc
new file mode 100644
index 0000000000000000000000000000000000000000..9737e953998b417d2fed149d916503c74a2fb0f4
--- /dev/null
+++ b/src/arm/simulator-arm.cc
@@ -0,0 +1,1687 @@
+// Copyright 2008 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following
+// disclaimer in the documentation and/or other materials provided
+// with the distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <stdlib.h>
+
+#include "v8.h"
+
+#include "disasm.h"
+#include "arm/constants-arm.h"
+#include "arm/simulator-arm.h"
+
+#if !defined(__arm__)
+
+// Only build the simulator if not compiling for real ARM hardware.
+namespace assembler { namespace arm {
+
+using ::v8::internal::Object;
+using ::v8::internal::PrintF;
+using ::v8::internal::OS;
+using ::v8::internal::ReadLine;
+using ::v8::internal::DeleteArray;
+
+// This macro provides a platform independent use of sscanf. The reason for
+// SScanF not being implemented in a platform independent was through
+// ::v8::internal::OS in the same way as SNPrintF is that the Windows C Run-Time
+// Library does not provide vsscanf.
+#define SScanF sscanf // NOLINT
+
+// The Debugger class is used by the simulator while debugging simulated ARM
+// code.
+class Debugger {
+ public:
+ explicit Debugger(Simulator* sim);
+ ~Debugger();
+
+ void Stop(Instr* instr);
+ void Debug();
+
+ private:
+ static const instr_t kBreakpointInstr =
+ ((AL << 28) | (7 << 25) | (1 << 24) | break_point);
+ static const instr_t kNopInstr =
+ ((AL << 28) | (13 << 21));
+
+ Simulator* sim_;
+
+ bool GetValue(char* desc, int32_t* value);
+
+ // 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();
+};
+
+
+Debugger::Debugger(Simulator* sim) {
+ sim_ = sim;
+}
+
+
+Debugger::~Debugger() {
+}
+
+
+
+#ifdef GENERATED_CODE_COVERAGE
+static FILE* coverage_log = NULL;
+
+
+static void InitializeCoverage() {
+ char* file_name = getenv("V8_GENERATED_CODE_COVERAGE_LOG");
+ if (file_name != NULL) {
+ coverage_log = fopen(file_name, "aw+");
+ }
+}
+
+
+void Debugger::Stop(Instr* instr) {
+ char* str = reinterpret_cast<char*>(instr->InstructionBits() & 0x0fffffff);
+ if (strlen(str) > 0) {
+ if (coverage_log != NULL) {
+ fprintf(coverage_log, "%s\n", str);
+ fflush(coverage_log);
+ }
+ instr->SetInstructionBits(0xe1a00000); // Overwrite with nop.
+ }
+ sim_->set_pc(sim_->get_pc() + Instr::kInstrSize);
+}
+
+#else // ndef GENERATED_CODE_COVERAGE
+
+static void InitializeCoverage() {
+}
+
+
+void Debugger::Stop(Instr* instr) {
+ const char* str = (const char*)(instr->InstructionBits() & 0x0fffffff);
+ PrintF("Simulator hit %s\n", str);
+ sim_->set_pc(sim_->get_pc() + Instr::kInstrSize);
+ Debug();
+}
+#endif
+
+
+static const char* reg_names[] = { "r0", "r1", "r2", "r3",
+ "r4", "r5", "r6", "r7",
+ "r8", "r9", "r10", "r11",
+ "r12", "r13", "r14", "r15",
+ "pc", "lr", "sp", "ip",
+ "fp", "sl", ""};
+
+static int reg_nums[] = { 0, 1, 2, 3,
+ 4, 5, 6, 7,
+ 8, 9, 10, 11,
+ 12, 13, 14, 15,
+ 15, 14, 13, 12,
+ 11, 10};
+
+
+static int RegNameToRegNum(char* name) {
+ int reg = 0;
+ while (*reg_names[reg] != 0) {
+ if (strcmp(reg_names[reg], name) == 0) {
+ return reg_nums[reg];
+ }
+ reg++;
+ }
+ return -1;
+}
+
+
+bool Debugger::GetValue(char* desc, int32_t* value) {
+ int regnum = RegNameToRegNum(desc);
+ if (regnum >= 0) {
+ if (regnum == 15) {
+ *value = sim_->get_pc();
+ } else {
+ *value = sim_->get_register(regnum);
+ }
+ return true;
+ } else {
+ return SScanF(desc, "%i", value) == 1;
+ }
+ return false;
+}
+
+
+bool Debugger::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 Debugger::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 Debugger::UndoBreakpoints() {
+ if (sim_->break_pc_ != NULL) {
+ sim_->break_pc_->SetInstructionBits(sim_->break_instr_);
+ }
+}
+
+
+void Debugger::RedoBreakpoints() {
+ if (sim_->break_pc_ != NULL) {
+ sim_->break_pc_->SetInstructionBits(kBreakpointInstr);
+ }
+}
+
+
+void Debugger::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()) {
+ disasm::NameConverter converter;
+ disasm::Disassembler dasm(converter);
+ // use a reasonably large buffer
+ v8::internal::EmbeddedVector<char, 256> buffer;
+ dasm.InstructionDecode(buffer,
+ reinterpret_cast<byte*>(sim_->get_pc()));
+ PrintF(" 0x%x %s\n", sim_->get_pc(), buffer.start());
+ last_pc = sim_->get_pc();
+ }
+ char* line = ReadLine("sim> ");
+ if (line == NULL) {
+ break;
+ } 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, "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) {
+ int32_t value;
+ if (GetValue(arg1, &value)) {
+ PrintF("%s: %d 0x%x\n", arg1, value, value);
+ } else {
+ PrintF("%s unrecognized\n", arg1);
+ }
+ } else {
+ PrintF("print value\n");
+ }
+ } else if ((strcmp(cmd, "po") == 0)
+ || (strcmp(cmd, "printobject") == 0)) {
+ if (args == 2) {
+ int32_t value;
+ if (GetValue(arg1, &value)) {
+ Object* obj = reinterpret_cast<Object*>(value);
+ USE(obj);
+ PrintF("%s: \n", arg1);
+#if defined(DEBUG)
+ obj->PrintLn();
+#endif // defined(DEBUG)
+ } else {
+ PrintF("%s unrecognized\n", arg1);
+ }
+ } else {
+ PrintF("printobject value\n");
+ }
+ } else if (strcmp(cmd, "disasm") == 0) {
+ disasm::NameConverter converter;
+ disasm::Disassembler dasm(converter);
+ // use a reasonably large buffer
+ v8::internal::EmbeddedVector<char, 256> buffer;
+
+ byte* cur = NULL;
+ byte* end = NULL;
+
+ if (args == 1) {
+ cur = reinterpret_cast<byte*>(sim_->get_pc());
+ end = cur + (10 * Instr::kInstrSize);
+ } else if (args == 2) {
+ int32_t value;
+ if (GetValue(arg1, &value)) {
+ cur = reinterpret_cast<byte*>(value);
+ // no length parameter passed, assume 10 instructions
+ end = cur + (10 * Instr::kInstrSize);
+ }
+ } else {
+ int32_t value1;
+ int32_t value2;
+ if (GetValue(arg1, &value1) && GetValue(arg2, &value2)) {
+ cur = reinterpret_cast<byte*>(value1);
+ end = cur + (value2 * Instr::kInstrSize);
+ }
+ }
+
+ while (cur < end) {
+ dasm.InstructionDecode(buffer, cur);
+ PrintF(" 0x%x %s\n", cur, buffer.start());
+ cur += Instr::kInstrSize;
+ }
+ } else if (strcmp(cmd, "gdb") == 0) {
+ PrintF("relinquishing control to gdb\n");
+ v8::internal::OS::DebugBreak();
+ PrintF("regaining control from gdb\n");
+ } else if (strcmp(cmd, "break") == 0) {
+ if (args == 2) {
+ int32_t value;
+ if (GetValue(arg1, &value)) {
+ if (!SetBreakpoint(reinterpret_cast<Instr*>(value))) {
+ PrintF("setting breakpoint failed\n");
+ }
+ } else {
+ PrintF("%s unrecognized\n", arg1);
+ }
+ } else {
+ PrintF("break addr\n");
+ }
+ } else if (strcmp(cmd, "del") == 0) {
+ if (!DeleteBreakpoint(NULL)) {
+ PrintF("deleting breakpoint failed\n");
+ }
+ } else if (strcmp(cmd, "flags") == 0) {
+ PrintF("N flag: %d; ", sim_->n_flag_);
+ PrintF("Z flag: %d; ", sim_->z_flag_);
+ PrintF("C flag: %d; ", sim_->c_flag_);
+ PrintF("V flag: %d\n", sim_->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->ConditionField() == special_condition) {
+ stop_instr->SetInstructionBits(kNopInstr);
+ } else {
+ PrintF("Not at debugger stop.");
+ }
+ } else {
+ PrintF("Unknown command: %s\n", cmd);
+ }
+ }
+ DeleteArray(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
+}
+
+
+Simulator::Simulator() {
+ // Setup simulator support first. Some of this information is needed to
+ // setup the architecture state.
+ size_t stack_size = 1 * 1024*1024; // allocate 1MB for stack
+ stack_ = reinterpret_cast<char*>(malloc(stack_size));
+ pc_modified_ = false;
+ icount_ = 0;
+ break_pc_ = NULL;
+ break_instr_ = 0;
+
+ // Setup architecture state.
+ // All registers are initialized to zero to start with.
+ for (int i = 0; i < num_registers; 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. To be safe in potential stack underflows we leave
+ // some buffer below.
+ registers_[sp] = reinterpret_cast<int32_t>(stack_) + stack_size - 64;
+ // 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] = bad_lr;
+ registers_[lr] = bad_lr;
+ InitializeCoverage();
+}
+
+
+// Create one simulator per thread and keep it in thread local storage.
+static v8::internal::Thread::LocalStorageKey simulator_key =
+ v8::internal::Thread::CreateThreadLocalKey();
+
+// Get the active Simulator for the current thread.
+Simulator* Simulator::current() {
+ Simulator* sim = reinterpret_cast<Simulator*>(
+ v8::internal::Thread::GetThreadLocal(simulator_key));
+ if (sim == NULL) {
+ // TODO(146): delete the simulator object when a thread goes away.
+ sim = new Simulator();
+ v8::internal::Thread::SetThreadLocal(simulator_key, sim);
+ }
+ return sim;
+}
+
+
+// Sets the register in the architecture state. It will also deal with updating
+// Simulator internal state for special registers such as PC.
+void Simulator::set_register(int reg, int32_t value) {
+ ASSERT((reg >= 0) && (reg < num_registers));
+ if (reg == pc) {
+ pc_modified_ = true;
+ }
+ registers_[reg] = value;
+}
+
+
+// Get the register from the architecture state. This function does handle
+// the special case of accessing the PC register.
+int32_t Simulator::get_register(int reg) const {
+ ASSERT((reg >= 0) && (reg < num_registers));
+ return registers_[reg] + ((reg == pc) ? Instr::kPCReadOffset : 0);
+}
+
+
+// Raw access to the PC register.
+void Simulator::set_pc(int32_t value) {
+ pc_modified_ = true;
+ registers_[pc] = value;
+}
+
+
+// Raw access to the PC register without the special adjustment when reading.
+int32_t Simulator::get_pc() const {
+ return registers_[pc];
+}
+
+
+// For use in calls that take two double values, constructed from r0, r1, r2
+// and r3.
+void Simulator::GetFpArgs(double* x, double* y) {
+ // We use a char buffer to get around the strict-aliasing rules which
+ // otherwise allow the compiler to optimize away the copy.
+ char buffer[2 * sizeof(registers_[0])];
+ // Registers 0 and 1 -> x.
+ memcpy(buffer, registers_, sizeof(buffer));
+ memcpy(x, buffer, sizeof(buffer));
+ // Registers 2 and 3 -> y.
+ memcpy(buffer, registers_ + 2, sizeof(buffer));
+ memcpy(y, buffer, sizeof(buffer));
+}
+
+
+void Simulator::SetFpResult(const double& result) {
+ char buffer[2 * sizeof(registers_[0])];
+ memcpy(buffer, &result, sizeof(buffer));
+ // result -> registers 0 and 1.
+ memcpy(registers_, buffer, sizeof(buffer));
+}
+
+
+void Simulator::TrashCallerSaveRegisters() {
+ // We don't trash the registers with the return value.
+ registers_[2] = 0x50Bad4U;
+ registers_[3] = 0x50Bad4U;
+ registers_[12] = 0x50Bad4U;
+}
+
+
+// The ARM cannot do unaligned reads and writes. On some ARM platforms an
+// interrupt is caused. On others it does a funky rotation thing. For now we
+// simply disallow unaligned reads, but at some point we may want to move to
+// emulating the rotate behaviour. 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 not
+// get the correct ARM-like behaviour on unaligned accesses.
+
+int Simulator::ReadW(int32_t addr, Instr* instr) {
+ if ((addr & 3) == 0) {
+ intptr_t* ptr = reinterpret_cast<intptr_t*>(addr);
+ return *ptr;
+ }
+ PrintF("Unaligned read at %x\n", addr);
+ UNIMPLEMENTED();
+ return 0;
+}
+
+
+void Simulator::WriteW(int32_t addr, int value, Instr* instr) {
+ if ((addr & 3) == 0) {
+ intptr_t* ptr = reinterpret_cast<intptr_t*>(addr);
+ *ptr = value;
+ return;
+ }
+ PrintF("Unaligned write at %x, pc=%p\n", addr, instr);
+ UNIMPLEMENTED();
+}
+
+
+uint16_t Simulator::ReadHU(int32_t addr, Instr* instr) {
+ if ((addr & 1) == 0) {
+ uint16_t* ptr = reinterpret_cast<uint16_t*>(addr);
+ return *ptr;
+ }
+ PrintF("Unaligned read at %x, pc=%p\n", addr, instr);
+ UNIMPLEMENTED();
+ return 0;
+}
+
+
+int16_t Simulator::ReadH(int32_t addr, Instr* instr) {
+ if ((addr & 1) == 0) {
+ int16_t* ptr = reinterpret_cast<int16_t*>(addr);
+ return *ptr;
+ }
+ PrintF("Unaligned read at %x\n", addr);
+ UNIMPLEMENTED();
+ return 0;
+}
+
+
+void Simulator::WriteH(int32_t addr, uint16_t value, Instr* instr) {
+ if ((addr & 1) == 0) {
+ uint16_t* ptr = reinterpret_cast<uint16_t*>(addr);
+ *ptr = value;
+ return;
+ }
+ PrintF("Unaligned write at %x, pc=%p\n", addr, instr);
+ UNIMPLEMENTED();
+}
+
+
+void Simulator::WriteH(int32_t addr, int16_t value, Instr* instr) {
+ if ((addr & 1) == 0) {
+ int16_t* ptr = reinterpret_cast<int16_t*>(addr);
+ *ptr = value;
+ return;
+ }
+ PrintF("Unaligned write at %x, pc=%p\n", addr, instr);
+ UNIMPLEMENTED();
+}
+
+
+uint8_t Simulator::ReadBU(int32_t addr) {
+ uint8_t* ptr = reinterpret_cast<uint8_t*>(addr);
+ return *ptr;
+}
+
+
+int8_t Simulator::ReadB(int32_t addr) {
+ int8_t* ptr = reinterpret_cast<int8_t*>(addr);
+ return *ptr;
+}
+
+
+void Simulator::WriteB(int32_t addr, uint8_t value) {
+ uint8_t* ptr = reinterpret_cast<uint8_t*>(addr);
+ *ptr = value;
+}
+
+
+void Simulator::WriteB(int32_t addr, int8_t value) {
+ int8_t* ptr = reinterpret_cast<int8_t*>(addr);
+ *ptr = value;
+}
+
+
+// Returns the limit of the stack area to enable checking for stack overflows.
+uintptr_t Simulator::StackLimit() const {
+ // Leave a safety margin of 256 bytes to prevent overrunning the stack when
+ // pushing values.
+ return reinterpret_cast<uintptr_t>(stack_) + 256;
+}
+
+
+// Unsupported instructions use Format to print an error and stop execution.
+void Simulator::Format(Instr* instr, const char* format) {
+ PrintF("Simulator found unsupported instruction:\n 0x%x: %s\n",
+ instr, format);
+ UNIMPLEMENTED();
+}
+
+
+// Checks if the current instruction should be executed based on its
+// condition bits.
+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.
+void Simulator::SetNZFlags(int32_t val) {
+ n_flag_ = (val < 0);
+ z_flag_ = (val == 0);
+}
+
+
+// Set the Carry flag.
+void Simulator::SetCFlag(bool val) {
+ c_flag_ = val;
+}
+
+
+// Set the oVerflow flag.
+void Simulator::SetVFlag(bool val) {
+ v_flag_ = val;
+}
+
+
+// Calculate C flag value for additions.
+bool Simulator::CarryFrom(int32_t left, int32_t right) {
+ uint32_t uleft = static_cast<uint32_t>(left);
+ uint32_t uright = static_cast<uint32_t>(right);
+ uint32_t urest = 0xffffffffU - uleft;
+
+ return (uright > urest);
+}
+
+
+// Calculate C flag value for subtractions.
+bool Simulator::BorrowFrom(int32_t left, int32_t right) {
+ uint32_t uleft = static_cast<uint32_t>(left);
+ uint32_t uright = static_cast<uint32_t>(right);
+
+ return (uright > uleft);
+}
+
+
+// Calculate V flag value for additions and subtractions.
+bool Simulator::OverflowFrom(int32_t alu_out,
+ int32_t left, int32_t right, bool addition) {
+ bool overflow;
+ if (addition) {
+ // operands have the same sign
+ overflow = ((left >= 0 && right >= 0) || (left < 0 && right < 0))
+ // and operands and result have different sign
+ && ((left < 0 && alu_out >= 0) || (left >= 0 && alu_out < 0));
+ } else {
+ // operands have different signs
+ overflow = ((left < 0 && right >= 0) || (left >= 0 && right < 0))
+ // and first operand and result have different signs
+ && ((left < 0 && alu_out >= 0) || (left >= 0 && alu_out < 0));
+ }
+ return overflow;
+}
+
+
+// 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)) {
+ UNIMPLEMENTED();
+ return result;
+ } 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: {
+ UNIMPLEMENTED();
+ break;
+ }
+
+ default: {
+ UNREACHABLE();
+ break;
+ }
+ }
+ } else {
+ // by register
+ int 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: {
+ UNIMPLEMENTED();
+ break;
+ }
+
+ default: {
+ UNREACHABLE();
+ break;
+ }
+ }
+ }
+ return result;
+}
+
+
+// Addressing Mode 1 - Data-processing operands:
+// Get the value based on the shifter_operand with immediate.
+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;
+}
+
+
+static int count_bits(int bit_vector) {
+ int count = 0;
+ while (bit_vector != 0) {
+ if ((bit_vector & 1) != 0) {
+ count++;
+ }
+ bit_vector >>= 1;
+ }
+ return count;
+}
+
+
+// Addressing Mode 4 - Load and Store Multiple
+void Simulator::HandleRList(Instr* instr, bool load) {
+ int rn = instr->RnField();
+ int32_t rn_val = get_register(rn);
+ int rlist = instr->RlistField();
+ int num_regs = count_bits(rlist);
+
+ intptr_t start_address = 0;
+ intptr_t end_address = 0;
+ switch (instr->PUField()) {
+ case 0: {
+ // Print("da");
+ UNIMPLEMENTED();
+ break;
+ }
+ case 1: {
+ // Print("ia");
+ start_address = rn_val;
+ end_address = rn_val + (num_regs * 4) - 4;
+ rn_val = rn_val + (num_regs * 4);
+ break;
+ }
+ case 2: {
+ // Print("db");
+ start_address = rn_val - (num_regs * 4);
+ end_address = rn_val - 4;
+ rn_val = start_address;
+ break;
+ }
+ case 3: {
+ // Print("ib");
+ UNIMPLEMENTED();
+ break;
+ }
+ default: {
+ UNREACHABLE();
+ break;
+ }
+ }
+ if (instr->HasW()) {
+ set_register(rn, rn_val);
+ }
+ intptr_t* address = reinterpret_cast<intptr_t*>(start_address);
+ int reg = 0;
+ while (rlist != 0) {
+ if ((rlist & 1) != 0) {
+ if (load) {
+ set_register(reg, *address);
+ } else {
+ *address = get_register(reg);
+ }
+ address += 1;
+ }
+ reg++;
+ rlist >>= 1;
+ }
+ ASSERT(end_address == ((intptr_t)address) - 4);
+}
+
+
+// Calls into the V8 runtime are based on this very simple interface.
+// Note: To be able to return two values from some calls the code in runtime.cc
+// uses the ObjectPair which is essentially two 32-bit values stuffed into a
+// 64-bit value. With the code below we assume that all runtime calls return
+// 64 bits of result. If they don't, the r1 result register contains a bogus
+// value, which is fine because it is caller-saved.
+typedef int64_t (*SimulatorRuntimeCall)(intptr_t arg0, intptr_t arg1);
+
+
+// Software interrupt instructions are used by the simulator to call into the
+// C-based V8 runtime.
+void Simulator::SoftwareInterrupt(Instr* instr) {
+ int swi = instr->SwiField();
+ switch (swi) {
+ case call_rt_r5: {
+ SimulatorRuntimeCall target =
+ reinterpret_cast<SimulatorRuntimeCall>(get_register(r5));
+ intptr_t arg0 = get_register(r0);
+ intptr_t arg1 = get_register(r1);
+ int64_t result = target(arg0, arg1);
+ int32_t lo_res = static_cast<int32_t>(result);
+ int32_t hi_res = static_cast<int32_t>(result >> 32);
+ set_register(r0, lo_res);
+ set_register(r1, hi_res);
+ set_pc(reinterpret_cast<int32_t>(instr) + Instr::kInstrSize);
+ break;
+ }
+ case call_rt_r2: {
+ SimulatorRuntimeCall target =
+ reinterpret_cast<SimulatorRuntimeCall>(get_register(r2));
+ intptr_t arg0 = get_register(r0);
+ intptr_t arg1 = get_register(r1);
+ int64_t result = target(arg0, arg1);
+ int32_t lo_res = static_cast<int32_t>(result);
+ int32_t hi_res = static_cast<int32_t>(result >> 32);
+ set_register(r0, lo_res);
+ set_register(r1, hi_res);
+ set_pc(reinterpret_cast<int32_t>(instr) + Instr::kInstrSize);
+ break;
+ }
+ case break_point: {
+ Debugger dbg(this);
+ dbg.Debug();
+ break;
+ }
+ {
+ double x, y, z;
+ case simulator_fp_add:
+ GetFpArgs(&x, &y);
+ z = x + y;
+ SetFpResult(z);
+ TrashCallerSaveRegisters();
+ set_pc(reinterpret_cast<int32_t>(instr) + Instr::kInstrSize);
+ break;
+ case simulator_fp_sub:
+ GetFpArgs(&x, &y);
+ z = x - y;
+ SetFpResult(z);
+ TrashCallerSaveRegisters();
+ set_pc(reinterpret_cast<int32_t>(instr) + Instr::kInstrSize);
+ break;
+ case simulator_fp_mul:
+ GetFpArgs(&x, &y);
+ z = x * y;
+ SetFpResult(z);
+ TrashCallerSaveRegisters();
+ set_pc(reinterpret_cast<int32_t>(instr) + Instr::kInstrSize);
+ 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.
+void Simulator::DecodeType01(Instr* instr) {
+ int type = instr->TypeField();
+ if ((type == 0) && instr->IsSpecialType0()) {
+ // multiply instruction or extra loads and stores
+ if (instr->Bits(7, 4) == 9) {
+ if (instr->Bit(24) == 0) {
+ // multiply instructions
+ int rd = instr->RdField();
+ int rm = instr->RmField();
+ int rs = instr->RsField();
+ int32_t rs_val = get_register(rs);
+ int32_t rm_val = get_register(rm);
+ if (instr->Bit(23) == 0) {
+ if (instr->Bit(21) == 0) {
+ // Format(instr, "mul'cond's 'rd, 'rm, 'rs");
+ int32_t alu_out = rm_val * rs_val;
+ set_register(rd, alu_out);
+ if (instr->HasS()) {
+ SetNZFlags(alu_out);
+ }
+ } else {
+ Format(instr, "mla'cond's 'rd, 'rm, 'rs, 'rn");
+ }
+ } else {
+ // Format(instr, "'um'al'cond's 'rn, 'rd, 'rs, 'rm");
+ int rn = instr->RnField();
+ int32_t hi_res = 0;
+ int32_t lo_res = 0;
+ if (instr->Bit(22) == 0) {
+ // signed multiply
+ UNIMPLEMENTED();
+ } else {
+ // unsigned multiply
+ uint64_t left_op = rm_val;
+ uint64_t right_op = rs_val;
+ uint64_t result = left_op * right_op;
+ hi_res = static_cast<int32_t>(result >> 32);
+ lo_res = static_cast<int32_t>(result & 0xffffffff);
+ }
+ set_register(rn, hi_res);
+ set_register(rd, lo_res);
+ if (instr->HasS()) {
+ UNIMPLEMENTED();
+ }
+ }
+ } else {
+ UNIMPLEMENTED(); // not used by V8
+ }
+ } else {
+ // extra load/store instructions
+ int rd = instr->RdField();
+ int rn = instr->RnField();
+ int32_t rn_val = get_register(rn);
+ int32_t addr = 0;
+ if (instr->Bit(22) == 0) {
+ int rm = instr->RmField();
+ int32_t rm_val = get_register(rm);
+ switch (instr->PUField()) {
+ case 0: {
+ // Format(instr, "'memop'cond'sign'h 'rd, ['rn], -'rm");
+ ASSERT(!instr->HasW());
+ addr = rn_val;
+ rn_val -= rm_val;
+ set_register(rn, rn_val);
+ break;
+ }
+ case 1: {
+ // Format(instr, "'memop'cond'sign'h 'rd, ['rn], +'rm");
+ ASSERT(!instr->HasW());
+ addr = rn_val;
+ rn_val += rm_val;
+ set_register(rn, rn_val);
+ break;
+ }
+ case 2: {
+ // Format(instr, "'memop'cond'sign'h 'rd, ['rn, -'rm]'w");
+ rn_val -= rm_val;
+ addr = rn_val;
+ if (instr->HasW()) {
+ set_register(rn, rn_val);
+ }
+ break;
+ }
+ case 3: {
+ // Format(instr, "'memop'cond'sign'h 'rd, ['rn, +'rm]'w");
+ rn_val += rm_val;
+ addr = rn_val;
+ if (instr->HasW()) {
+ set_register(rn, rn_val);
+ }
+ 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'sign'h 'rd, ['rn], #-'off8");
+ ASSERT(!instr->HasW());
+ addr = rn_val;
+ rn_val -= imm_val;
+ set_register(rn, rn_val);
+ break;
+ }
+ case 1: {
+ // Format(instr, "'memop'cond'sign'h 'rd, ['rn], #+'off8");
+ ASSERT(!instr->HasW());
+ addr = rn_val;
+ rn_val += imm_val;
+ set_register(rn, rn_val);
+ break;
+ }
+ case 2: {
+ // Format(instr, "'memop'cond'sign'h 'rd, ['rn, #-'off8]'w");
+ rn_val -= imm_val;
+ addr = rn_val;
+ if (instr->HasW()) {
+ set_register(rn, rn_val);
+ }
+ break;
+ }
+ case 3: {
+ // Format(instr, "'memop'cond'sign'h 'rd, ['rn, #+'off8]'w");
+ rn_val += imm_val;
+ addr = rn_val;
+ if (instr->HasW()) {
+ set_register(rn, rn_val);
+ }
+ break;
+ }
+ default: {
+ // The PU field is a 2-bit field.
+ UNREACHABLE();
+ break;
+ }
+ }
+ }
+ if (instr->HasH()) {
+ if (instr->HasSign()) {
+ if (instr->HasL()) {
+ int16_t val = ReadH(addr, instr);
+ set_register(rd, val);
+ } else {
+ int16_t val = get_register(rd);
+ WriteH(addr, val, instr);
+ }
+ } else {
+ 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 {
+ // signed byte loads
+ ASSERT(instr->HasSign());
+ ASSERT(instr->HasL());
+ int8_t val = ReadB(addr);
+ set_register(rd, val);
+ }
+ return;
+ }
+ } else {
+ int rd = instr->RdField();
+ int rn = instr->RnField();
+ int32_t rn_val = get_register(rn);
+ int32_t shifter_operand = 0;
+ bool shifter_carry_out = 0;
+ if (type == 0) {
+ shifter_operand = GetShiftRm(instr, &shifter_carry_out);
+ } else {
+ ASSERT(instr->TypeField() == 1);
+ shifter_operand = GetImm(instr, &shifter_carry_out);
+ }
+ 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(!BorrowFrom(rn_val, shifter_operand));
+ SetVFlag(OverflowFrom(alu_out, rn_val, shifter_operand, false));
+ }
+ 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(!BorrowFrom(shifter_operand, rn_val));
+ SetVFlag(OverflowFrom(alu_out, shifter_operand, rn_val, false));
+ }
+ 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));
+ SetVFlag(OverflowFrom(alu_out, rn_val, shifter_operand, true));
+ }
+ break;
+ }
+
+ case ADC: {
+ Format(instr, "adc'cond's 'rd, 'rn, 'shift_rm");
+ Format(instr, "adc'cond's 'rd, 'rn, 'imm");
+ break;
+ }
+
+ case SBC: {
+ Format(instr, "sbc'cond's 'rd, 'rn, 'shift_rm");
+ Format(instr, "sbc'cond's 'rd, 'rn, 'imm");
+ break;
+ }
+
+ case RSC: {
+ Format(instr, "rsc'cond's 'rd, 'rn, 'shift_rm");
+ Format(instr, "rsc'cond's 'rd, 'rn, 'imm");
+ 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 {
+ UNIMPLEMENTED();
+ }
+ 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 {
+ UNIMPLEMENTED();
+ }
+ 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(!BorrowFrom(rn_val, shifter_operand));
+ SetVFlag(OverflowFrom(alu_out, rn_val, shifter_operand, false));
+ } else {
+ UNIMPLEMENTED();
+ }
+ break;
+ }
+
+ case CMN: {
+ if (instr->HasS()) {
+ Format(instr, "cmn'cond 'rn, 'shift_rm");
+ Format(instr, "cmn'cond 'rn, 'imm");
+ } else {
+ UNIMPLEMENTED();
+ }
+ 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;
+ }
+ }
+ }
+}
+
+
+void Simulator::DecodeType2(Instr* instr) {
+ int rd = instr->RdField();
+ int rn = instr->RnField();
+ int32_t rn_val = get_register(rn);
+ int32_t im_val = instr->Offset12Field();
+ int32_t addr = 0;
+ switch (instr->PUField()) {
+ case 0: {
+ // Format(instr, "'memop'cond'b 'rd, ['rn], #-'off12");
+ ASSERT(!instr->HasW());
+ addr = rn_val;
+ rn_val -= im_val;
+ set_register(rn, rn_val);
+ break;
+ }
+ case 1: {
+ // Format(instr, "'memop'cond'b 'rd, ['rn], #+'off12");
+ ASSERT(!instr->HasW());
+ addr = rn_val;
+ rn_val += im_val;
+ set_register(rn, rn_val);
+ break;
+ }
+ case 2: {
+ // Format(instr, "'memop'cond'b 'rd, ['rn, #-'off12]'w");
+ rn_val -= im_val;
+ addr = rn_val;
+ if (instr->HasW()) {
+ set_register(rn, rn_val);
+ }
+ break;
+ }
+ case 3: {
+ // Format(instr, "'memop'cond'b 'rd, ['rn, #+'off12]'w");
+ rn_val += im_val;
+ addr = rn_val;
+ if (instr->HasW()) {
+ set_register(rn, rn_val);
+ }
+ break;
+ }
+ default: {
+ UNREACHABLE();
+ break;
+ }
+ }
+ if (instr->HasB()) {
+ if (instr->HasL()) {
+ byte val = ReadBU(addr);
+ set_register(rd, val);
+ } else {
+ byte 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::DecodeType3(Instr* instr) {
+ int rd = instr->RdField();
+ int rn = instr->RnField();
+ int32_t rn_val = get_register(rn);
+ bool shifter_carry_out = 0;
+ int32_t shifter_operand = GetShiftRm(instr, &shifter_carry_out);
+ int32_t addr = 0;
+ switch (instr->PUField()) {
+ case 0: {
+ ASSERT(!instr->HasW());
+ Format(instr, "'memop'cond'b 'rd, ['rn], -'shift_rm");
+ break;
+ }
+ case 1: {
+ ASSERT(!instr->HasW());
+ Format(instr, "'memop'cond'b 'rd, ['rn], +'shift_rm");
+ break;
+ }
+ case 2: {
+ // Format(instr, "'memop'cond'b 'rd, ['rn, -'shift_rm]'w");
+ addr = rn_val - shifter_operand;
+ if (instr->HasW()) {
+ set_register(rn, addr);
+ }
+ break;
+ }
+ case 3: {
+ // Format(instr, "'memop'cond'b 'rd, ['rn, +'shift_rm]'w");
+ addr = rn_val + shifter_operand;
+ if (instr->HasW()) {
+ set_register(rn, addr);
+ }
+ break;
+ }
+ default: {
+ UNREACHABLE();
+ break;
+ }
+ }
+ if (instr->HasB()) {
+ UNIMPLEMENTED();
+ } 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) {
+ UNIMPLEMENTED();
+}
+
+
+void Simulator::DecodeType7(Instr* instr) {
+ if (instr->Bit(24) == 1) {
+ // Format(instr, "swi 'swi");
+ SoftwareInterrupt(instr);
+ } else {
+ UNIMPLEMENTED();
+ }
+}
+
+
+// Executes the current instruction.
+void Simulator::InstructionDecode(Instr* instr) {
+ pc_modified_ = false;
+ if (instr->ConditionField() == special_condition) {
+ Debugger dbg(this);
+ dbg.Stop(instr);
+ return;
+ }
+ if (::v8::internal::FLAG_trace_sim) {
+ disasm::NameConverter converter;
+ disasm::Disassembler dasm(converter);
+ // use a reasonably large buffer
+ v8::internal::EmbeddedVector<char, 256> buffer;
+ dasm.InstructionDecode(buffer,
+ reinterpret_cast<byte*>(instr));
+ PrintF(" 0x%x %s\n", instr, buffer.start());
+ }
+ if (ConditionallyExecute(instr)) {
+ switch (instr->TypeField()) {
+ case 0:
+ case 1: {
+ DecodeType01(instr);
+ break;
+ }
+ case 2: {
+ DecodeType2(instr);
+ break;
+ }
+ case 3: {
+ DecodeType3(instr);
+ break;
+ }
+ case 4: {
+ DecodeType4(instr);
+ break;
+ }
+ case 5: {
+ DecodeType5(instr);
+ break;
+ }
+ case 6: {
+ DecodeType6(instr);
+ break;
+ }
+ case 7: {
+ DecodeType7(instr);
+ break;
+ }
+ default: {
+ UNIMPLEMENTED();
+ break;
+ }
+ }
+ }
+ if (!pc_modified_) {
+ set_register(pc, reinterpret_cast<int32_t>(instr) + Instr::kInstrSize);
+ }
+}
+
+
+//
+void Simulator::Execute() {
+ // Get the PC to simulate. Cannot use the accessor here as we need the
+ // raw PC value and not the one used as input to arithmetic instructions.
+ int program_counter = get_pc();
+
+ if (::v8::internal::FLAG_stop_sim_at == 0) {
+ // Fast version of the dispatch loop without checking whether the simulator
+ // should be stopping at a particular executed instruction.
+ while (program_counter != end_sim_pc) {
+ Instr* instr = reinterpret_cast<Instr*>(program_counter);
+ icount_++;
+ InstructionDecode(instr);
+ program_counter = get_pc();
+ }
+ } else {
+ // FLAG_stop_sim_at is at the non-default value. Stop in the debugger when
+ // we reach the particular instuction count.
+ while (program_counter != end_sim_pc) {
+ Instr* instr = reinterpret_cast<Instr*>(program_counter);
+ icount_++;
+ if (icount_ == ::v8::internal::FLAG_stop_sim_at) {
+ Debugger dbg(this);
+ dbg.Debug();
+ } else {
+ InstructionDecode(instr);
+ }
+ program_counter = get_pc();
+ }
+ }
+}
+
+
+Object* Simulator::Call(int32_t entry, int32_t p0, int32_t p1, int32_t p2,
+ int32_t p3, int32_t p4) {
+ // Setup parameters
+ set_register(r0, p0);
+ set_register(r1, p1);
+ set_register(r2, p2);
+ set_register(r3, p3);
+ intptr_t* stack_pointer = reinterpret_cast<intptr_t*>(get_register(sp));
+ *(--stack_pointer) = p4;
+ set_register(sp, reinterpret_cast<int32_t>(stack_pointer));
+
+ // Prepare to execute the code at entry
+ set_register(pc, entry);
+ // Put down marker for end of simulation. The simulator will stop simulation
+ // when the PC reaches this value. By saving the "end simulation" value into
+ // the LR the simulation stops when returning to this call point.
+ set_register(lr, end_sim_pc);
+
+ // Remember the values of callee-saved registers.
+ // The code below assumes that r9 is not used as sb (static base) in
+ // simulator code and therefore is regarded as a callee-saved register.
+ int32_t r4_val = get_register(r4);
+ int32_t r5_val = get_register(r5);
+ int32_t r6_val = get_register(r6);
+ int32_t r7_val = get_register(r7);
+ int32_t r8_val = get_register(r8);
+ int32_t r9_val = get_register(r9);
+ int32_t r10_val = get_register(r10);
+ int32_t r11_val = get_register(r11);
+
+ // Setup the callee-saved registers with a known value. To be able to check
+ // that they are preserved properly across JS execution.
+ int32_t callee_saved_value = icount_;
+ set_register(r4, callee_saved_value);
+ set_register(r5, callee_saved_value);
+ set_register(r6, callee_saved_value);
+ set_register(r7, callee_saved_value);
+ set_register(r8, callee_saved_value);
+ set_register(r9, callee_saved_value);
+ set_register(r10, callee_saved_value);
+ set_register(r11, callee_saved_value);
+
+ // Start the simulation
+ Execute();
+
+ // Check that the callee-saved registers have been preserved.
+ CHECK_EQ(get_register(r4), callee_saved_value);
+ CHECK_EQ(get_register(r5), callee_saved_value);
+ CHECK_EQ(get_register(r6), callee_saved_value);
+ CHECK_EQ(get_register(r7), callee_saved_value);
+ CHECK_EQ(get_register(r8), callee_saved_value);
+ CHECK_EQ(get_register(r9), callee_saved_value);
+ CHECK_EQ(get_register(r10), callee_saved_value);
+ CHECK_EQ(get_register(r11), callee_saved_value);
+
+ // Restore callee-saved registers with the original value.
+ set_register(r4, r4_val);
+ set_register(r5, r5_val);
+ set_register(r6, r6_val);
+ set_register(r7, r7_val);
+ set_register(r8, r8_val);
+ set_register(r9, r9_val);
+ set_register(r10, r10_val);
+ set_register(r11, r11_val);
+
+ int result = get_register(r0);
+ return reinterpret_cast<Object*>(result);
+}
+
+} } // namespace assembler::arm
+
+#endif // !defined(__arm__)
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