Begins work on ARM64, first assembler test.

runtime/vm/simulator_arm64.h

Index: runtime/vm/simulator_arm64.h
===================================================================
--- runtime/vm/simulator_arm64.h	(revision 0)
+++ runtime/vm/simulator_arm64.h	(revision 0)
@@ -0,0 +1,160 @@
+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Declares a Simulator for ARM64 instructions if we are not generating a native
+// ARM64 binary. This Simulator allows us to run and debug ARM64 code generation
+// on regular desktop machines.
+// Dart calls into generated code by "calling" the InvokeDartCode stub,
+// which will start execution in the Simulator or forwards to the real entry
+// on a ARM64 HW platform.
+
+#ifndef VM_SIMULATOR_ARM64_H_
+#define VM_SIMULATOR_ARM64_H_
+
+#ifndef VM_SIMULATOR_H_
+#error Do not include simulator_arm64.h directly; use simulator.h.
+#endif
+
+#include "vm/constants_arm64.h"
+#include "vm/object.h"
+
+namespace dart {
+
+class Isolate;
+
+class Simulator {
+ public:
+  static const uword kSimulatorStackUnderflowSize = 64;
+
+  Simulator();
+  ~Simulator();
+
+  // The currently executing Simulator instance, which is associated to the
+  // current isolate
+  static Simulator* Current();
+
+  // Accessors for register state.
+  void set_register(Register reg, int64_t value, R31Type r31t = R31IsUndef);
+  int64_t get_register(Register reg, R31Type r31t = R31IsUndef) const;
+  void set_wregister(Register reg, int32_t value, R31Type r31t = R31IsUndef);
+  int32_t get_wregister(Register reg, R31Type r31t = R31IsUndef) const;
+
+  int64_t get_pc() const;
+  void set_pc(int64_t pc);
+
+  // Accessor to the internal simulator stack top.
+  uword StackTop() const;
+
+  // The isolate's top_exit_frame_info refers to a Dart frame in the simulator
+  // stack. The simulator's top_exit_frame_info refers to a C++ frame in the
+  // native stack.
+  uword top_exit_frame_info() const { return top_exit_frame_info_; }
+  void set_top_exit_frame_info(uword value) { top_exit_frame_info_ = value; }
+
+  // Call on program start.
+  static void InitOnce() {}
+
+  // Dart generally calls into generated code with 5 parameters. This is a
+  // convenience function, which sets up the simulator state and grabs the
+  // result on return. The return value is R0. The parameters are placed in
+  // R0-3.
+  int64_t Call(int64_t entry,
+               int64_t parameter0,
+               int64_t parameter1,
+               int64_t parameter2,
+               int64_t parameter3);
+
+  void Longjmp(uword pc,
+               uword sp,
+               uword fp,
+               RawObject* raw_exception,
+               RawObject* raw_stacktrace) {
+    UNIMPLEMENTED();
+  }
+
+ private:
+  // Known bad pc value to ensure that the simulator does not execute
+  // without being properly setup.
+  static const uword kBadLR = -1;
+  // A pc value used to signal the simulator to stop execution.  Generally
+  // the lr is set to this value on transition from native C code to
+  // simulated execution, so that the simulator can "return" to the native
+  // C code.
+  static const uword kEndSimulatingPC = -2;
+
+  // CPU state.
+  int64_t registers_[kNumberOfCpuRegisters];
+  bool n_flag_;
+  bool z_flag_;
+  bool c_flag_;
+  bool v_flag_;
+
+  // Simulator support.
+  int64_t pc_;
+  char* stack_;
+  bool pc_modified_;
+  intptr_t icount_;
+  static int64_t flag_stop_sim_at_;
+  uword top_exit_frame_info_;
+
+  // Registered breakpoints.
+  Instr* break_pc_;
+  int64_t break_instr_;
+
+  // Illegal memory access support.
+  static bool IsIllegalAddress(uword addr) {
+    return addr < 64*1024;
+  }
+  void HandleIllegalAccess(uword addr, Instr* instr);
+
+  // Handles a legal instruction that the simulator does not implement.
+  void UnimplementedInstruction(Instr* instr);
+
+  // Unsupported instructions use Format to print an error and stop execution.
+  void Format(Instr* instr, const char* format);
+
+  // Helper functions to set the conditional flags in the architecture state.
+  void SetNZFlagsW(int32_t val);
+  bool CarryFromW(int32_t left, int32_t right);
+  bool BorrowFromW(int32_t left, int32_t right);
+  bool OverflowFromW(
+      int32_t alu_out, int32_t left, int32_t right, bool addition);
+
+  void SetNZFlagsX(int64_t val);
+  bool CarryFromX(int64_t left, int64_t right);
+  bool BorrowFromX(int64_t left, int64_t right);
+  bool OverflowFromX(
+      int64_t alu_out, int64_t left, int64_t right, bool addition);
+
+  void SetCFlag(bool val);
+  void SetVFlag(bool val);
+
+  int64_t ShiftOperand(uint8_t reg_size,
+                       int64_t value,
+                       Shift shift_type,
+                       uint8_t amount);
+
+  int64_t ExtendOperand(uint8_t reg_size,
+                        int64_t value,
+                        Extend extend_type,
+                        uint8_t amount);
+
+  int64_t DecodeShiftExtendOperand(Instr* instr);
+
+  // Decode instructions.
+  void InstructionDecode(Instr* instr);
+  #define DECODE_OP(op)                                                        \
+    void Decode##op(Instr* instr);
+  APPLY_OP_LIST(DECODE_OP)
+  #undef DECODE_OP
+
+  // Executes ARM64 instructions until the PC reaches kEndSimulatingPC.
+  void Execute();
+
+  DISALLOW_COPY_AND_ASSIGN(Simulator);
+};
+
+}  // namespace dart
+
+#endif  // VM_SIMULATOR_ARM64_H_