Revert "Refactor transitioning stores."

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "x64/lithium-codegen-x64.h"
 #include "code-stubs.h"
@@ skipping 4003 matching lines @@
         Register value = ToRegister(instr->value());
         Condition cc = masm()->CheckSmi(value);
         DeoptimizeIf(cc, instr->environment());
 
         // We know now that value is not a smi, so we can omit the check below.
         check_needed = OMIT_SMI_CHECK;
       }
     }
   } else if (representation.IsDouble()) {
     ASSERT(access.IsInobject());
+    ASSERT(!hinstr->has_transition());
     ASSERT(!hinstr->NeedsWriteBarrier());
     XMMRegister value = ToDoubleRegister(instr->value());
     __ movsd(FieldOperand(object, offset), value);
     return;
   }
 
+  if (hinstr->has_transition()) {
+    Handle<Map> transition = hinstr->transition_map();
+    AddDeprecationDependency(transition);
+    if (!hinstr->NeedsWriteBarrierForMap()) {
+      __ Move(FieldOperand(object, HeapObject::kMapOffset), transition);
+    } else {
+      Register temp = ToRegister(instr->temp());
+      __ Move(kScratchRegister, transition);
+      __ movp(FieldOperand(object, HeapObject::kMapOffset), kScratchRegister);
+      // Update the write barrier for the map field.
+      __ RecordWriteField(object,
+                          HeapObject::kMapOffset,
+                          kScratchRegister,
+                          temp,
+                          kSaveFPRegs,
+                          OMIT_REMEMBERED_SET,
+                          OMIT_SMI_CHECK);
+    }
+  }
+
   // Do the store.
   Register write_register = object;
   if (!access.IsInobject()) {
     write_register = ToRegister(instr->temp());
     __ movp(write_register, FieldOperand(object, JSObject::kPropertiesOffset));
   }
 
   if (representation.IsSmi() && SmiValuesAre32Bits() &&
       hinstr->value()->representation().IsInteger32()) {
     ASSERT(hinstr->store_mode() == STORE_TO_INITIALIZED_ENTRY);
@@ skipping 1659 matching lines @@
   __ bind(deferred->exit());
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64