fast path for api function creation

src/builtins.cc

 // Copyright 2012 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/api.h"
 #include "src/api-natives.h"
 #include "src/arguments.h"
 #include "src/base/once.h"
@@ skipping 1129 matching lines @@
 
  private:
   DISALLOW_COPY_AND_ASSIGN(RelocatableArguments);
 };
 
 }  // namespace
 
 
 MaybeHandle<Object> Builtins::InvokeApiFunction(Handle<JSFunction> function,
                                                 Handle<Object> receiver,
-                                                int argc,
-                                                Handle<Object> args[]) {
+                                                int argc, Handle<Object> args[],
+                                                bool is_construct) {
   // Construct BuiltinArguments object: function, arguments reversed, receiver.
   const int kBufferSize = 32;
   Object* small_argv[kBufferSize];
   Object** argv;
   if (argc + 2 <= kBufferSize) {
     argv = small_argv;
   } else {
     argv = new Object* [argc + 2];
   }
   argv[argc + 1] = *receiver;
   for (int i = 0; i < argc; ++i) {
     argv[argc - i] = *args[i];
   }
   argv[0] = *function;
   MaybeHandle<Object> result;
   {
     auto isolate = function->GetIsolate();
     RelocatableArguments arguments(isolate, argc + 2, &argv[argc + 1]);
-    result = HandleApiCallHelper<false>(isolate, arguments);
+    if (is_construct) {
+      result = HandleApiCallHelper<true>(isolate, arguments);
+    } else {
+      result = HandleApiCallHelper<false>(isolate, arguments);
+    }
   }
   if (argv != small_argv) {
     delete[] argv;
   }
   return result;
 }
 
 
 // Helper function to handle calls to non-function objects created through the
 // API. The object can be called as either a constructor (using new) or just as
@@ skipping 470 matching lines @@
 }
 BUILTIN_LIST_C(DEFINE_BUILTIN_ACCESSOR_C)
 BUILTIN_LIST_A(DEFINE_BUILTIN_ACCESSOR_A)
 BUILTIN_LIST_H(DEFINE_BUILTIN_ACCESSOR_H)
 BUILTIN_LIST_DEBUG_A(DEFINE_BUILTIN_ACCESSOR_A)
 #undef DEFINE_BUILTIN_ACCESSOR_C
 #undef DEFINE_BUILTIN_ACCESSOR_A
 
 
 } }  // namespace v8::internal