Improve property access with keys that can always be converted into a symbol string.

src/ic.cc

 // Copyright 2006-2009 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
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@@ skipping 1125 matching lines @@
 
 #ifdef DEBUG
   TraceIC("LoadIC", name, state, target());
 #endif
 }
 
 
 MaybeObject* KeyedLoadIC::Load(State state,
                                Handle<Object> object,
                                Handle<Object> key) {
+  // Check for values that can be converted into a symbol.

[Mads Ager (chromium), 2011/03/31 09:41:49]

Could you file a bug report stating that this is put in because Kraken 1.1 is
not released in the web runner. Kraken 1.0 accesses undefined and NaN in arrays
a lot and this speeds it up. We have put it in so people do not make wrong
conclusions based on broken benchmarks. Once the web runner is updated to Kraken
1.1 which does correct array accesses we should get rid of this again.

+  HandleScope scope(isolate());
+  if (key->IsHeapNumber() &&
+      isnan(HeapNumber::cast(*key)->value())) {
+    key = isolate()->factory()->nan_symbol();
+  } else if (key->IsUndefined()) {
+    key = isolate()->factory()->undefined_symbol();
+  }
+
   if (key->IsSymbol()) {
     Handle<String> name = Handle<String>::cast(key);
 
     // If the object is undefined or null it's illegal to try to get any
     // of its properties; throw a TypeError in that case.
     if (object->IsUndefined() || object->IsNull()) {
       return TypeError("non_object_property_load", object, name);
     }
 
     if (FLAG_use_ic) {
@@ skipping 1214 matching lines @@
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal