Added pretenuring support for call new.

BUG=
R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/16226012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14935 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/flag-definitions.h

@@ -193,6 +193,9 @@ DEFINE_bool(clever_optimizations,
             true,
             "Optimize object size, Array shift, DOM strings and string +")
 DEFINE_bool(pretenuring, true, "allocate objects in old space")
+// TODO(hpayer): We will remove this flag as soon as we have pretenuring
+// support for specific allocation sites.
+DEFINE_bool(pretenuring_call_new, false, "pretenure call new")
 DEFINE_bool(track_fields, true, "track fields with only smi values")
 DEFINE_bool(track_double_fields, true, "track fields with double values")
 DEFINE_bool(track_heap_object_fields, true, "track fields with heap values")

src/hydrogen.cc

@@ -8780,11 +8780,19 @@ void HOptimizedGraphBuilder::VisitCallNew(CallNew* expr) {
     HValue* size_in_bytes =
         AddInstruction(new(zone()) HConstant(instance_size,
             Representation::Integer32()));
+
+    HAllocate::Flags flags = HAllocate::DefaultFlags();
+    if (FLAG_pretenuring_call_new &&
+        isolate()->heap()->ShouldGloballyPretenure()) {
+      flags = static_cast<HAllocate::Flags>(
+          flags | HAllocate::CAN_ALLOCATE_IN_OLD_POINTER_SPACE);
+    }
+
     HInstruction* receiver =
         AddInstruction(new(zone()) HAllocate(context,
                                              size_in_bytes,
                                              HType::JSObject(),
-                                             HAllocate::DefaultFlags()));
+                                             flags));
     HAllocate::cast(receiver)->set_known_initial_map(initial_map);
 
     // Load the initial map from the constructor.

test/cctest/test-heap.cc

@@ -2183,6 +2183,30 @@ TEST(OptimizedAllocationArrayLiterals) {
 }
 
 
+TEST(OptimizedPretenuringCallNew) {
+  i::FLAG_allow_natives_syntax = true;
+  i::FLAG_pretenuring_call_new = true;
+  CcTest::InitializeVM();
+  if (!i::V8::UseCrankshaft() || i::FLAG_always_opt) return;
+  if (i::FLAG_gc_global || i::FLAG_stress_compaction) return;
+  v8::HandleScope scope(CcTest::isolate());
+  HEAP->SetNewSpaceHighPromotionModeActive(true);
+
+  AlwaysAllocateScope always_allocate;
+  v8::Local<v8::Value> res = CompileRun(
+      "function g() { this.a = 0; }"
+      "function f() {"
+      "  return new g();"
+      "};"
+      "f(); f(); f();"
+      "%OptimizeFunctionOnNextCall(f);"
+      "f();");
+
+  Handle<JSObject> o =
+      v8::Utils::OpenHandle(*v8::Handle<v8::Object>::Cast(res));
+  CHECK(HEAP->InOldPointerSpace(*o));
+}
+
 static int CountMapTransitions(Map* map) {
   return map->transitions()->number_of_transitions();
 }