Support allocation sinking for compound objects.

runtime/vm/deferred_objects.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/deferred_objects.h"
 
 #include "vm/deopt_instructions.h"
 #include "vm/flags.h"
 #include "vm/object.h"
 
@@ skipping 79 matching lines @@
   if (FLAG_trace_deoptimization_verbose) {
     OS::PrintErr("writing instance ref at %" Px ": %s\n",
                  reinterpret_cast<uword>(slot()),
                  Instance::Handle(obj->object()).ToCString());
   }
 }
 
 
 RawInstance* DeferredObject::object() {
   if (object_ == NULL) {
-    Materialize();
+    Create();
   }
   return object_->raw();
 }
 
 
-void DeferredObject::Materialize() {
+void DeferredObject::Create() {
+  if (object_ != NULL) {
+    return;
+  }
+
   Class& cls = Class::Handle();
   cls ^= GetClass();
 
   if (FLAG_trace_deoptimization_verbose) {
     OS::PrintErr("materializing instance of %s (%" Px ", %" Pd " fields)\n",
                  cls.ToCString(),
                  reinterpret_cast<uword>(args_),
                  field_count_);
   }
 
-  const Instance& obj = Instance::ZoneHandle(Instance::New(cls));
+  object_ = &Instance::ZoneHandle(Instance::New(cls));
+}
+
+
+void DeferredObject::Fill() {
+  Create();  // Ensure instance is created.
+
+  Class& cls = Class::Handle();
+  cls ^= GetClass();
+
+  const Instance& obj = *object_;
 
   Smi& offset = Smi::Handle();
   Field& field = Field::Handle();
   Object& value = Object::Handle();
   const Array& offset_map = Array::Handle(cls.OffsetToFieldMap());
 
   for (intptr_t i = 0; i < field_count_; i++) {
     offset ^= GetFieldOffset(i);
     field ^= offset_map.At(offset.Value() / kWordSize);
     value = GetValue(i);
     if (!field.IsNull()) {
       obj.SetField(field, value);
       if (FLAG_trace_deoptimization_verbose) {
         OS::PrintErr("    %s <- %s\n",
                      String::Handle(field.name()).ToCString(),
                      value.ToCString());
       }
     } else {
       ASSERT(cls.IsSignatureClass() ||
              (offset.Value() == cls.type_arguments_field_offset()));
       obj.SetFieldAtOffset(offset.Value(), value);
       if (FLAG_trace_deoptimization_verbose) {
         OS::PrintErr("    null Field @ offset(%" Pd ") <- %s\n",
                      offset.Value(),
                      value.ToCString());
       }
     }
   }
-
-  object_ = &obj;
 }
 
 }  // namespace dart