Some string optimizations:

src/codegen.cc

 // Copyright 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 342 matching lines @@
 
 // Special cases: These 'runtime calls' manipulate the current
 // frame and are only used 1 or two places, so we generate them
 // inline instead of generating calls to them.  They are used
 // for implementing Function.prototype.call() and
 // Function.prototype.apply().
 CodeGenerator::InlineRuntimeLUT CodeGenerator::kInlineRuntimeLUT[] = {
   {&CodeGenerator::GenerateIsSmi, "_IsSmi"},
   {&CodeGenerator::GenerateIsNonNegativeSmi, "_IsNonNegativeSmi"},
   {&CodeGenerator::GenerateIsArray, "_IsArray"},
+  {&CodeGenerator::GenerateIsRegExp, "_IsRegExp"},
   {&CodeGenerator::GenerateIsConstructCall, "_IsConstructCall"},
   {&CodeGenerator::GenerateArgumentsLength, "_ArgumentsLength"},
   {&CodeGenerator::GenerateArgumentsAccess, "_Arguments"},
   {&CodeGenerator::GenerateClassOf, "_ClassOf"},
   {&CodeGenerator::GenerateValueOf, "_ValueOf"},
   {&CodeGenerator::GenerateSetValueOf, "_SetValueOf"},
   {&CodeGenerator::GenerateFastCharCodeAt, "_FastCharCodeAt"},
   {&CodeGenerator::GenerateObjectEquals, "_ObjectEquals"},
   {&CodeGenerator::GenerateLog, "_Log"},
   {&CodeGenerator::GenerateRandomPositiveSmi, "_RandomPositiveSmi"},
@@ skipping 150 matching lines @@
   }
 }
 
 
 void ApiGetterEntryStub::SetCustomCache(Code* value) {
   info()->set_load_stub_cache(value);
 }
 
 
 } }  // namespace v8::internal