Pretenure call new support.

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index d3d7b5837a0c5e3d9a09ba4a58ce9486773818e8..c7f86c85b1806e127592c91af283c40ed7908a29 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -8216,12 +8216,27 @@ void HOptimizedGraphBuilder::VisitCallNew(CallNew* expr) {
 
     // Allocate an instance of the implicit receiver object.
     HValue* size_in_bytes = Add<HConstant>(instance_size);
-    PretenureFlag pretenure_flag =
-        (FLAG_pretenuring_call_new && !FLAG_allocation_site_pretenuring) ?
-            isolate()->heap()->GetPretenureMode() : NOT_TENURED;
+    HAllocationMode allocation_mode;
+    if (FLAG_pretenuring_call_new) {
+      if (FLAG_allocation_site_pretenuring) {
+        // Try to use pretenuring feedback.
+        Handle<AllocationSite> allocation_site = expr->allocation_site();
+        if (!allocation_site.is_null()) {

[Hannes Payer (out of office), 2014/02/18 16:24:26]

When is the allocation_site null?

[mvstanton, 2014/02/19 08:40:26]

Wow. Never. Simplifying this. In the past it was more like, "if the call new
site never went megamorphic then it could be null." However, we only come down
this code path anywhere if we are monomorphic.

BTW, two lines in type-info.cc could be simplified,
TypeFeedbackOracle::CallIsMonomorphic() and
TypeFeedbackOracle::CallNewIsMonomorphic(). Those calls were accepting an
AllocationSite in their type vector slot, but now we've separated it out into a
different slot.

+          allocation_mode = HAllocationMode(allocation_site);
+          // Take a dependency on allocation site.
+          AllocationSite::AddDependentCompilationInfo(allocation_site,
+                                                      AllocationSite::TENURING,
+                                                      top_info());
+        }
+      } else {
+        allocation_mode = HAllocationMode(
+            isolate()->heap()->GetPretenureMode());
+      }
+    }
+
     HAllocate* receiver =
-        Add<HAllocate>(size_in_bytes, HType::JSObject(), pretenure_flag,
-        JS_OBJECT_TYPE);
+        BuildAllocate(size_in_bytes, HType::JSObject(), JS_OBJECT_TYPE,
+                      allocation_mode);
     receiver->set_known_initial_map(initial_map);
 
     // Load the initial map from the constructor.