Beings adding SIMD support to arm64.

runtime/vm/simulator_arm64.h

 // 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 SimulatorSetjmpBuffer;
 
 typedef struct {
-  int64_t lo;
-  int64_t hi;
+  union {
+    int64_t i64[2];
+    int32_t i32[4];
+  } bits;
 } simd_value_t;
 
 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.
   // The default value for R31Type has to be R31IsSP because get_register is
   // accessed from architecture independent code through SPREG without
   // specifying the type. We also can't translate a dummy value for SPREG into
   // a real value because the architecture independent code expects SPREG to
   // be a real register value.
   void set_register(Register reg, int64_t value, R31Type r31t = R31IsSP);
   int64_t get_register(Register reg, R31Type r31t = R31IsSP) const;
   void set_wregister(Register reg, int32_t value, R31Type r31t = R31IsSP);
   int32_t get_wregister(Register reg, R31Type r31t = R31IsSP) const;
 
-  // Get and set a V register in double ('d') mode. Setting clears the high
-  // 64 bits of the V register. Getting ignores the high 64 bits.
-  int64_t get_vregisterd(VRegister reg) const;
-  void set_vregisterd(VRegister reg, int64_t value);
+  int32_t get_vregisters(VRegister reg, int idx) const;
+  void set_vregisters(VRegister reg, int idx, int32_t value);
+
+  int64_t get_vregisterd(VRegister reg, int idx) const;
+  void set_vregisterd(VRegister reg, int idx, int64_t value);
+
   void get_vregister(VRegister reg, simd_value_t* value) const;
   void set_vregister(VRegister reg, const simd_value_t& value);
 
   int64_t get_pc() const;
   int64_t get_last_pc() const;
   void set_pc(int64_t pc);
 
   // Accessor to the internal simulator stack top.
   uword StackTop() const;
 
@@ skipping 150 matching lines @@
   }
 
   friend class SimulatorDebugger;
   friend class SimulatorSetjmpBuffer;
   DISALLOW_COPY_AND_ASSIGN(Simulator);
 };
 
 }  // namespace dart
 
 #endif  // VM_SIMULATOR_ARM64_H_