Pretenure code generation corner case with new space COW arrays.

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 5324ef39cb320f0662ffbefec360cf87a4bf93f8..de5dae1759416c94cfe4972bd0e966c43fb3b7e1 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -9774,6 +9774,15 @@ HInstruction* HOptimizedGraphBuilder::BuildFastLiteral(
       elements->map() != isolate()->heap()->fixed_cow_array_map()) ?
           elements->Size() : 0;
 

[Hannes Payer (out of office), 2014/03/17 09:37:18]

This method needs more comments... please explain what is going on here.

[mvstanton, 2014/03/17 12:25:28]

Done.

+  if (pretenure_flag == TENURED &&
+      elements->map() == isolate()->heap()->fixed_cow_array_map() &&
+      isolate()->heap()->InNewSpace(*elements)) {
+    elements = Handle<FixedArrayBase>(
+        isolate()->factory()->CopyAndTenureFixedCOWArray(
+            Handle<FixedArray>::cast(elements)));
+    boilerplate_object->set_elements(*elements);
+  }
+
   HInstruction* object_elements = NULL;
   if (elements_size > 0) {
     HValue* object_elements_size = Add<HConstant>(elements_size);