Support unaligned integer loads on ARM and MIPS.

runtime/vm/assembler_mips.h

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef RUNTIME_VM_ASSEMBLER_MIPS_H_
 #define RUNTIME_VM_ASSEMBLER_MIPS_H_
 
 #ifndef RUNTIME_VM_ASSEMBLER_H_
 #error Do not include assembler_mips.h directly; use assembler.h instead.
 #endif
@@ skipping 1581 matching lines @@
   // Set up a Dart frame for a function compiled for on-stack replacement.
   // The frame layout is a normal Dart frame, but the frame is partially set
   // up on entry (it is the frame of the unoptimized code).
   void EnterOsrFrame(intptr_t extra_size);
 
   Address ElementAddressForIntIndex(bool is_external,
                                     intptr_t cid,
                                     intptr_t index_scale,
                                     Register array,
                                     intptr_t index) const;
+  void LoadElementAddressForIntIndex(Register address,
+                                     bool is_external,
+                                     intptr_t cid,
+                                     intptr_t index_scale,
+                                     Register array,
+                                     intptr_t index);
   Address ElementAddressForRegIndex(bool is_load,
                                     bool is_external,
                                     intptr_t cid,
                                     intptr_t index_scale,
                                     Register array,
                                     Register index);
+  void LoadElementAddressForRegIndex(Register address,
+                                     bool is_load,
+                                     bool is_external,
+                                     intptr_t cid,
+                                     intptr_t index_scale,
+                                     Register array,
+                                     Register index);
+
+  void LoadHalfWordUnaligned(Register dst, Register addr, Register tmp);
+  void LoadHalfWordUnsignedUnaligned(Register dst, Register addr, Register tmp);
+  void StoreHalfWordUnaligned(Register src, Register addr, Register tmp);
+  void LoadWordUnaligned(Register dst, Register addr, Register tmp);
+  void StoreWordUnaligned(Register src, Register addr, Register tmp);
 
   static Address VMTagAddress() {
     return Address(THR, Thread::vm_tag_offset());
   }
 
   // On some other platforms, we draw a distinction between safe and unsafe
   // smis.
   static bool IsSafe(const Object& object) { return true; }
   static bool IsSafeSmi(const Object& object) { return object.IsSmi(); }
 
@@ skipping 140 matching lines @@
                                   Register value,
                                   Label* no_update);
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_ASSEMBLER_MIPS_H_