Enable pretenuring of fast literals in high promotion mode.

src/hydrogen.cc

 // Copyright 2012 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 10090 matching lines @@
     Handle<JSObject> original_boilerplate_object,
     int data_size,
     int pointer_size,
     AllocationSiteMode mode,
     BailoutId id) {
   Zone* zone = this->zone();
   int total_size = data_size + pointer_size;
 
   NoObservableSideEffectsScope no_effects(this);
 
+  HAllocate::Flags flags = HAllocate::CAN_ALLOCATE_IN_NEW_SPACE;
+  // TODO(hpayer): add support for old data space
+  if (FLAG_pretenure_literals &&
+      isolate()->heap()->ShouldGloballyPretenure() &&
+      data_size == 0) {
+    flags = static_cast<HAllocate::Flags>(
+        flags | HAllocate::CAN_ALLOCATE_IN_OLD_POINTER_SPACE);
+  }
+
   HValue* size_in_bytes =
       AddInstruction(new(zone) HConstant(total_size,
           Representation::Integer32()));
   HInstruction* result =
       AddInstruction(new(zone) HAllocate(context,
                                          size_in_bytes,
                                          HType::JSObject(),
-                                         HAllocate::CAN_ALLOCATE_IN_NEW_SPACE));
+                                         flags));
   int offset = 0;
   BuildEmitDeepCopy(boilerplate_object, original_boilerplate_object, result,
                     &offset, mode, id);
   ASSERT_EQ(total_size, offset);
   return result;
 }
 
 
 void HOptimizedGraphBuilder::BuildEmitDeepCopy(
     Handle<JSObject> boilerplate_object,
@@ skipping 1538 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal