Perform string add in generated code on IA-32 platforms...

src/runtime.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
 //       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 3765 matching lines @@
   // NewNumberFromDouble may return a Smi instead of a Number object
   return Heap::NewNumberFromDouble(x);
 }
 
 
 static Object* Runtime_StringAdd(Arguments args) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
   CONVERT_CHECKED(String, str1, args[0]);
   CONVERT_CHECKED(String, str2, args[1]);
+  Counters::string_add_runtime.Increment();
   return Heap::AllocateConsString(str1, str2);
 }
 
 
 template<typename sinkchar>
 static inline void StringBuilderConcatHelper(String* special,
                                              sinkchar* sink,
                                              FixedArray* fixed_array,
                                              int array_length) {
   int position = 0;
@@ skipping 4162 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     Counters::gc_last_resort_from_js.Increment();
     Heap::CollectAllGarbage(false);
   }
 }
 
 
 } }  // namespace v8::internal