Only remove the code object that caused the monomorphic prototype...

src/ic.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 125 matching lines @@
   Map* map = GetCodeCacheMapForObject(receiver);
 
   // Decide whether the inline cache failed because of changes to the
   // receiver itself or changes to one of its prototypes.
   //
   // If there are changes to the receiver itself, the map of the
   // receiver will have changed and the current target will not be in
   // the receiver map's code cache.  Therefore, if the current target
   // is in the receiver map's code cache, the inline cache failed due
   // to prototype check failure.
-  if (map->IncludedInCodeCache(target)) {
+  int index = map->IndexInCodeCache(target);
+  if (index >= 0) {
     // For keyed load/store, the most likely cause of cache failure is
     // that the key has changed.  We do not distinguish between
     // prototype and non-prototype failures for keyed access.
     Code::Kind kind = target->kind();
     if (kind == Code::KEYED_LOAD_IC || kind == Code::KEYED_STORE_IC) {
       return MONOMORPHIC;
     }
 
-    // Clear the code cache for this map to avoid hitting the same
-    // invalid stub again.  It seems likely that most of the code in
-    // the cache is invalid if one of the stubs is so we flush the
-    // entire code cache.
-    map->ClearCodeCache();
+    // Remove the target from the code cache to avoid hitting the same
+    // invalid stub again.
+    map->RemoveFromCodeCache(index);
 
     return MONOMORPHIC_PROTOTYPE_FAILURE;
   }
 
   // The builtins object is special.  It only changes when JavaScript
   // builtins are loaded lazily.  It is important to keep inline
   // caches for the builtins object monomorphic.  Therefore, if we get
   // an inline cache miss for the builtins object after lazily loading
   // JavaScript builtins, we clear the code cache and return
   // uninitialized as the state to force the inline cache back to
@@ skipping 986 matching lines @@
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal