Faster invocation of custom comparator function.

src/x64/codegen-x64.cc

Index: src/x64/codegen-x64.cc
diff --git a/src/x64/codegen-x64.cc b/src/x64/codegen-x64.cc
index 3b03477c45ba06d69bde43b3021a7483204b7832..54c5b5c75af16e07c10eb7b10df70a4ecef46ccb 100644
--- a/src/x64/codegen-x64.cc
+++ b/src/x64/codegen-x64.cc
@@ -4140,6 +4140,22 @@ void CodeGenerator::GenerateNumberToString(ZoneList<Expression*>* args) {
 }
 
 
+void CodeGenerator::GenerateCallFunction(ZoneList<Expression*>* args) {
+  Comment cmnt(masm_, "[ GenerateCallFunction");
+
+  ASSERT(args->length() >= 2);
+
+  int n_args = args->length() - 2;  // for receiver and function.
+  Load(args->at(0));  // receiver
+  for (int i = 0; i < n_args; i++) {
+    Load(args->at(i + 1));
+  }
+  Load(args->at(n_args + 1));  // function
+  Result result = frame_->CallJSFunction(n_args);
+  frame_->Push(&result);
+}
+
+
 void CodeGenerator::GenerateMathSin(ZoneList<Expression*>* args) {
   ASSERT_EQ(args->length(), 1);
   // Load the argument on the stack and jump to the runtime.