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

src/ia32/codegen-ia32.cc

Index: src/ia32/codegen-ia32.cc
===================================================================
--- src/ia32/codegen-ia32.cc	(revision 5865)
+++ src/ia32/codegen-ia32.cc	(working copy)
@@ -4897,7 +4897,8 @@
 
 
 Result CodeGenerator::InstantiateFunction(
-    Handle<SharedFunctionInfo> function_info) {
+    Handle<SharedFunctionInfo> function_info,
+    bool pretenure) {
   // The inevitable call will sync frame elements to memory anyway, so
   // we do it eagerly to allow us to push the arguments directly into
   // place.
@@ -4905,7 +4906,9 @@
 
   // 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() && function_info->num_literals() == 0) {
+  if (scope()->is_function_scope() &&
+      function_info->num_literals() == 0 &&
+      !pretenure) {
     FastNewClosureStub stub;
     frame()->EmitPush(Immediate(function_info));
     return frame()->CallStub(&stub, 1);
@@ -4914,7 +4917,10 @@
     // shared function info.
     frame()->EmitPush(esi);
     frame()->EmitPush(Immediate(function_info));
-    return frame()->CallRuntime(Runtime::kNewClosure, 2);
+    frame()->EmitPush(Immediate(pretenure
+                                ? Factory::true_value()
+                                : Factory::false_value()));
+    return frame()->CallRuntime(Runtime::kNewClosure, 3);
   }
 }
 
@@ -4930,7 +4936,7 @@
     SetStackOverflow();
     return;
   }
-  Result result = InstantiateFunction(function_info);
+  Result result = InstantiateFunction(function_info, node->pretenure());
   frame()->Push(&result);
 }
 
@@ -4939,7 +4945,7 @@
     SharedFunctionInfoLiteral* node) {
   ASSERT(!in_safe_int32_mode());
   Comment cmnt(masm_, "[ SharedFunctionInfoLiteral");
-  Result result = InstantiateFunction(node->shared_function_info());
+  Result result = InstantiateFunction(node->shared_function_info(), false);
   frame()->Push(&result);
 }