Force pretenuring of closures that are immediately assigned to...

src/x64/full-codegen-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 819 matching lines @@
   // Remove the pointers stored on the stack.
   __ bind(loop_statement.break_target());
   __ addq(rsp, Immediate(5 * kPointerSize));
 
   // Exit and decrement the loop depth.
   __ bind(&exit);
   decrement_loop_depth();
 }
 
 
-void FullCodeGenerator::EmitNewClosure(Handle<SharedFunctionInfo> info) {
+void FullCodeGenerator::EmitNewClosure(Handle<SharedFunctionInfo> info,
+                                       bool pretenure) {
   // Use the fast case closure allocation code that allocates in new
   // space for nested functions that don't need literals cloning.
-  if (scope()->is_function_scope() && info->num_literals() == 0) {
+  if (scope()->is_function_scope() &&
+      info->num_literals() == 0 &&
+      !pretenure) {
     FastNewClosureStub stub;
     __ Push(info);
     __ CallStub(&stub);
   } else {
     __ push(rsi);
     __ Push(info);
-    __ CallRuntime(Runtime::kNewClosure, 2);
+    __ Push(pretenure ? Factory::true_value() : Factory::false_value());
+    __ CallRuntime(Runtime::kNewClosure, 3);
   }
   context()->Plug(rax);
 }
 
 
 void FullCodeGenerator::VisitVariableProxy(VariableProxy* expr) {
   Comment cmnt(masm_, "[ VariableProxy");
   EmitVariableLoad(expr->var());
 }
 
@@ skipping 2604 matching lines @@
   __ ret(0);
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64