- Added fast case for extending the JSObject properties storage....

src/stub-cache-arm.cc

 // Copyright 2006-2008 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 398 matching lines @@
 
   // Stub never generated for non-global objects that require access
   // checks.
   ASSERT(object->IsJSGlobalObject() || !object->IsAccessCheckNeeded());
 
   // Get the properties array
   __ ldr(r1, FieldMemOperand(r3, JSObject::kPropertiesOffset));
 
   // Perform map transition for the receiver if necessary.
   if (transition != NULL) {
-    // Update the map of the object; no write barrier updating is
-    // needed because the map is never in new space.
-    __ mov(ip, Operand(Handle<Map>(transition)));
-    __ str(ip, FieldMemOperand(r3, HeapObject::kMapOffset));
+    if (object->map()->unused_property_fields() == 0) {
+      // The properties must be extended before we can store the value.
+      // We jump to a runtime call that extends the propeties array.
+      __ mov(r2, Operand(Handle<Map>(transition)));
+      Handle<Code> ic(Builtins::builtin(Builtins::StoreIC_ExtendStorage));
+      __ Jump(ic, RelocInfo::CODE_TARGET);
+    } else {
+      // Update the map of the object; no write barrier updating is
+      // needed because the map is never in new space.
+      __ mov(ip, Operand(Handle<Map>(transition)));
+      __ str(ip, FieldMemOperand(r3, HeapObject::kMapOffset));
+    }
   }
 
   // Write to the properties array.
   int offset = index * kPointerSize + Array::kHeaderSize;
   __ str(r0, FieldMemOperand(r1, offset));
 
   // Skip updating write barrier if storing a smi.
   __ tst(r0, Operand(kSmiTagMask));
   __ b(eq, &exit);
 
@@ skipping 356 matching lines @@
                                                   String* name) {
   UNIMPLEMENTED();
   return Heap::undefined_value();
 }
 
 
 
 #undef __
 
 } }  // namespace v8::internal