First implementation of allocation elimination in Hydrogen.

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index 777661570aaf7d86736695d6a09f9c20d0877988..7b4e7f91c32af4cf35937f0e48d9a01a99928e54 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -4512,8 +4512,37 @@ MaybeObject* Heap::AllocateJSObjectFromMap(Map* map, PretenureFlag pretenure) {
 }
 
 
-MaybeObject* Heap::AllocateJSObjectFromMapWithAllocationSite(Map* map,
-    Handle<AllocationSite> allocation_site) {
+MaybeObject* Heap::AllocateJSObjectFromMapForDeoptimizer(
+    Map* map, PretenureFlag pretenure) {
+  // JSFunctions should be allocated using AllocateFunction to be
+  // properly initialized.
+  ASSERT(map->instance_type() != JS_FUNCTION_TYPE);
+
+  // Both types of global objects should be allocated using
+  // AllocateGlobalObject to be properly initialized.
+  ASSERT(map->instance_type() != JS_GLOBAL_OBJECT_TYPE);
+  ASSERT(map->instance_type() != JS_BUILTINS_OBJECT_TYPE);
+
+  // Allocate the JSObject.
+  AllocationSpace space =
+      (pretenure == TENURED) ? OLD_POINTER_SPACE : NEW_SPACE;
+  if (map->instance_size() > Page::kMaxNonCodeHeapObjectSize) space = LO_SPACE;
+  Object* obj;
+  MaybeObject* maybe_obj = Allocate(map, space);
+  if (!maybe_obj->To(&obj)) return maybe_obj;
+
+  // Initialize the JSObject.
+  InitializeJSObjectFromMap(JSObject::cast(obj),
+                            empty_fixed_array(),
+                            map);
+  ASSERT(JSObject::cast(obj)->HasFastElements() ||
+         JSObject::cast(obj)->HasExternalArrayElements());
+  return obj;
+}
+
+
+MaybeObject* Heap::AllocateJSObjectFromMapWithAllocationSite(
+    Map* map, Handle<AllocationSite> allocation_site) {
   // JSFunctions should be allocated using AllocateFunction to be
   // properly initialized.
   ASSERT(map->instance_type() != JS_FUNCTION_TYPE);