Narrow cases where Sparse/Smart versions of Array methods are used

src/runtime/runtime-array.cc

 // Copyright 2014 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 "src/v8.h"
 
 #include "src/arguments.h"
 #include "src/runtime/runtime-utils.h"
 
 namespace v8 {
@@ skipping 1025 matching lines @@
   HandleScope scope(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(JSObject, array, 0);
   RUNTIME_ASSERT(!array->HasExternalArrayElements() &&
                  !array->HasFixedTypedArrayElements());
   JSObject::NormalizeElements(array);
   return *array;
 }
 
 
+RUNTIME_FUNCTION(Runtime_HasComplexElements) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, array, 0);
+  for (PrototypeIterator iter(isolate, array,
+                              PrototypeIterator::START_AT_RECEIVER);
+       !iter.IsAtEnd(); iter.Advance()) {
+    if (PrototypeIterator::GetCurrent(iter)->IsJSProxy()) {
+      return isolate->heap()->true_value();
+    }
+    Handle<JSObject> current =
+        Handle<JSObject>::cast(PrototypeIterator::GetCurrent(iter));
+    if (current->HasIndexedInterceptor()) {
+      return isolate->heap()->true_value();
+    }
+    if (!current->HasDictionaryElements()) continue;
+    if (current->element_dictionary()->HasComplexElements()) {
+      return isolate->heap()->true_value();
+    }
+  }
+  return isolate->heap()->false_value();
+}
+
+
 // TODO(dcarney): remove this function when TurboFan supports it.
 // Takes the object to be iterated over and the result of GetPropertyNamesFast
 // Returns pair (cache_array, cache_type).
 RUNTIME_FUNCTION_RETURN_PAIR(Runtime_ForInInit) {
   SealHandleScope scope(isolate);
   DCHECK(args.length() == 2);
   // This simulates CONVERT_ARG_HANDLE_CHECKED for calls returning pairs.
   // Not worth creating a macro atm as this function should be removed.
   if (!args[0]->IsJSReceiver() || !args[1]->IsObject()) {
     Object* error = isolate->ThrowIllegalOperation();
@@ skipping 95 matching lines @@
 }
 
 
 RUNTIME_FUNCTION(RuntimeReference_FastOneByteArrayJoin) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 2);
   return isolate->heap()->undefined_value();
 }
 }
 }  // namespace v8::internal