Merged r13420 into 3.12 branch.

src/mips/lithium-codegen-mips.cc

 // Copyright 2012 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
@@ skipping 3800 matching lines @@
   ElementsKind from_kind = from_map->elements_kind();
   ElementsKind to_kind = to_map->elements_kind();
 
   __ mov(ToRegister(instr->result()), object_reg);
 
   Label not_applicable;
   __ lw(scratch, FieldMemOperand(object_reg, HeapObject::kMapOffset));
   __ Branch(&not_applicable, ne, scratch, Operand(from_map));
 
   __ li(new_map_reg, Operand(to_map));
-  if (IsFastSmiElementsKind(from_kind) && IsFastObjectElementsKind(to_kind)) {
+  if (IsSimpleMapChangeTransition(from_kind, to_kind)) {
     __ sw(new_map_reg, FieldMemOperand(object_reg, HeapObject::kMapOffset));
     // Write barrier.
     __ RecordWriteField(object_reg, HeapObject::kMapOffset, new_map_reg,
                         scratch, kRAHasBeenSaved, kDontSaveFPRegs);
   } else if (IsFastSmiElementsKind(from_kind) &&
              IsFastDoubleElementsKind(to_kind)) {
     Register fixed_object_reg = ToRegister(instr->temp_reg());
     ASSERT(fixed_object_reg.is(a2));
     ASSERT(new_map_reg.is(a3));
     __ mov(fixed_object_reg, object_reg);
@@ skipping 1433 matching lines @@
   __ Subu(scratch, result, scratch);
   __ lw(result, FieldMemOperand(scratch,
                                 FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal