8155643: Java crash with assert in Xcomp mode and disabled ReduceInitialCardMarks

We should not emit a subtype check for CloneOop arraycopy.

Reviewed-by: kvn

hotspot/test/compiler/arraycopy/TestObjectArrayClone.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8155643
+ * @summary Test Object.clone() intrinsic if ReduceInitialCardMarks is disabled.
+ * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -Xcomp -XX:CompileOnly=TestObjectArrayClone.test -XX:-ReduceInitialCardMarks TestObjectArrayClone
+ */
+public class TestObjectArrayClone {
+
+    public static TestObjectArrayClone[] test(TestObjectArrayClone[] arr) {
+        return arr.clone();
+    }
+
+    public static void main(String[] args) {
+        test(new TestObjectArrayClone[42]);
+    }
+}
+