Move backend specific files to separate directories.

src/simulator-arm.cc

-// 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 "constants-arm.h"
-#include "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__)