Faster invocation of custom comparator function.

src/x64/virtual-frame-x64.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 806 matching lines @@
     arg1->ToRegister(rax);
     arg0->ToRegister(rdx);
   }
 
   arg0->Unuse();
   arg1->Unuse();
   return RawCallStub(stub);
 }
 
 
+Result VirtualFrame::CallJSFunction(int arg_count) {
+  Result function = Pop();
+
+  // InvokeFunction requires function in rdi.  Move it in there.
+  function.ToRegister(rdi);
+  function.Unuse();
+
+  // +1 for receiver.
+  PrepareForCall(arg_count + 1, arg_count + 1);
+  ASSERT(cgen()->HasValidEntryRegisters());
+  ParameterCount count(arg_count);
+  __ InvokeFunction(rdi, count, CALL_FUNCTION);
+  RestoreContextRegister();
+  Result result = cgen()->allocator()->Allocate(rax);
+  ASSERT(result.is_valid());
+  return result;
+}
+
+
 void VirtualFrame::SyncElementBelowStackPointer(int index) {
   // Emit code to write elements below the stack pointer to their
   // (already allocated) stack address.
   ASSERT(index <= stack_pointer_);
   FrameElement element = elements_[index];
   ASSERT(!element.is_synced());
   switch (element.type()) {
     case FrameElement::INVALID:
       break;
 
@@ skipping 275 matching lines @@
   // Grow the expression stack by handler size less one (the return
   // address is already pushed by a call instruction).
   Adjust(kHandlerSize - 1);
   __ PushTryHandler(IN_JAVASCRIPT, type);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal