Implement simple fast-path code for functions containing this property stores and global variables.

src/data-flow.cc

 // Copyright 2010 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 178 matching lines @@
     CatchExtensionObject* expr) {
   UNREACHABLE();
 }
 
 
 void AstLabeler::VisitAssignment(Assignment* expr) {
   Property* prop = expr->target()->AsProperty();
   ASSERT(prop != NULL);
   if (prop != NULL) {
     ASSERT(prop->key()->IsPropertyName());
-    if (prop->obj()->AsVariableProxy() == NULL ||
-        !prop->obj()->AsVariableProxy()->var()->is_this())
+    VariableProxy* proxy = prop->obj()->AsVariableProxy();
+    if (proxy != NULL && proxy->var()->is_this()) {
+      has_this_properties_ = true;
+    } else {
       Visit(prop->obj());
+    }
   }
   Visit(expr->value());
   expr->set_num(next_number_++);
 }
 
 
 void AstLabeler::VisitThrow(Throw* expr) {
   UNREACHABLE();
 }
 
@@ skipping 43 matching lines @@
 void AstLabeler::VisitThisFunction(ThisFunction* expr) {
   UNREACHABLE();
 }
 
 
 void AstLabeler::VisitDeclaration(Declaration* decl) {
   UNREACHABLE();
 }
 
 } }  // namespace v8::internal