Support unaligned integer loads on ARM and MIPS.

runtime/vm/assembler_arm.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_ARM_H_
 #define RUNTIME_VM_ASSEMBLER_ARM_H_
 
 #ifndef RUNTIME_VM_ASSEMBLER_H_
 #error Do not include assembler_arm.h directly; use assembler.h instead.
 #endif
@@ skipping 953 matching lines @@
                                         Heap::Space space);
 
   Address ElementAddressForIntIndex(bool is_load,
                                     bool is_external,
                                     intptr_t cid,
                                     intptr_t index_scale,
                                     Register array,
                                     intptr_t index,
                                     Register temp);
 
+  void LoadElementAddressForIntIndex(Register address,
+                                     bool is_load,
+                                     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);
+
   // If allocation tracing for |cid| is enabled, will jump to |trace| label,
   // which will allocate in the runtime where tracing occurs.
   void MaybeTraceAllocation(intptr_t cid,
                             Register temp_reg,
                             Label* trace);
 
   // Inlined allocation of an instance of class 'cls', code has no runtime
   // calls. Jump to 'failure' if the instance cannot be allocated here.
   // Allocated instance is returned in 'instance_reg'.
   // Only the tags field of the object is initialized.
@@ skipping 181 matching lines @@
                                   Register value,
                                   Label* no_update);
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_ASSEMBLER_ARM_H_