diff --git a/hotspot/make/linux/makefiles/adlc.make b/hotspot/make/linux/makefiles/adlc.make
index 92b8b9b3911..f2faad16caf 100644
--- a/hotspot/make/linux/makefiles/adlc.make
+++ b/hotspot/make/linux/makefiles/adlc.make
@@ -66,7 +66,7 @@ CXXFLAGS += -DASSERT
 
 # CFLAGS_WARN holds compiler options to suppress/enable warnings.
 # Compiler warnings are treated as errors
-CFLAGS_WARN = $(WARNINGS_ARE_ERRORS)
+CFLAGS_WARN = $(WARNINGS_ARE_ERRORS) -Wno-register
 CFLAGS += $(CFLAGS_WARN)
 
 OBJECTNAMES = \
diff --git a/hotspot/src/share/vm/opto/type.cpp b/hotspot/src/share/vm/opto/type.cpp
index 58572f137db..7e839ba6599 100644
--- a/hotspot/src/share/vm/opto/type.cpp
+++ b/hotspot/src/share/vm/opto/type.cpp
@@ -2552,13 +2552,18 @@ TypeOopPtr::TypeOopPtr(TYPES t, PTR ptr, ciKlass* k, bool xk, ciObject* o, int o
         } else if (klass() == ciEnv::current()->Class_klass() &&
                    _offset >= InstanceMirrorKlass::offset_of_static_fields()) {
           // Static fields
-          assert(o != NULL, "must be constant");
-          ciInstanceKlass* k = o->as_instance()->java_lang_Class_klass()->as_instance_klass();
-          ciField* field = k->get_field_by_offset(_offset, true);
-          assert(field != NULL, "missing field");
-          BasicType basic_elem_type = field->layout_type();
-          _is_ptr_to_narrowoop = UseCompressedOops && (basic_elem_type == T_OBJECT ||
-                                                       basic_elem_type == T_ARRAY);
+          ciField* field = NULL;
+          if (o != NULL) {
+            ciInstanceKlass* k = o->as_instance()->java_lang_Class_klass()->as_instance_klass();
+            field = k->get_field_by_offset(_offset, true);
+          }
+          if (field != NULL) {
+            BasicType basic_elem_type = field->layout_type();
+            _is_ptr_to_narrowoop = UseCompressedOops && is_reference_type(basic_elem_type);
+          } else {
+            // unsafe access
+            _is_ptr_to_narrowoop = UseCompressedOops;
+          }
         } else {
           // Instance fields which contains a compressed oop references.
           field = ik->get_field_by_offset(_offset, false);