--- /dev/null	2020-01-17 11:46:19.065201212 +0100
+++ new/test/hotspot/jtreg/gc/shenandoah/compiler/TestClone.java	2020-01-17 17:11:17.012126792 +0100
@@ -0,0 +1,239 @@
+/*
+ * Copyright (c) 2019, Red Hat, Inc. 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 TestClone
+ * @summary Test clone barriers work correctly
+ * @key gc
+ * @requires vm.gc.Shenandoah & !vm.graal.enabled
+ *
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:+UseShenandoahGC
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:+UseShenandoahGC
+ *                   -Xint
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:+UseShenandoahGC
+ *                   -XX:-TieredCompilation
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:+UseShenandoahGC
+ *                   -XX:TieredStopAtLevel=1
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:+UseShenandoahGC
+ *                   -XX:TieredStopAtLevel=4
+ *                   TestClone
+ */
+
+/*
+ * @test TestClone
+ * @summary Test clone barriers work correctly
+ * @key gc
+ * @requires vm.gc.Shenandoah & !vm.graal.enabled
+ *
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:+UseShenandoahGC
+ *                   -XX:+ShenandoahVerify
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:+UseShenandoahGC
+ *                   -XX:+ShenandoahVerify
+ *                   -Xint
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:+UseShenandoahGC
+ *                   -XX:+ShenandoahVerify
+ *                   -XX:-TieredCompilation
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:+UseShenandoahGC
+ *                   -XX:+ShenandoahVerify
+ *                   -XX:TieredStopAtLevel=1
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:+UseShenandoahGC
+ *                   -XX:+ShenandoahVerify
+ *                   -XX:TieredStopAtLevel=4
+ *                   TestClone
+ */
+
+/*
+ * @test TestClone
+ * @summary Test clone barriers work correctly
+ * @key gc
+ * @requires vm.gc.Shenandoah & !vm.graal.enabled
+ *
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
+ *                   -Xint
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
+ *                   -XX:-TieredCompilation
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
+ *                   -XX:TieredStopAtLevel=1
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
+ *                   -XX:TieredStopAtLevel=4
+ *                   TestClone
+ */
+
+/*
+ * @test TestClone
+ * @summary Test clone barriers work correctly
+ * @key gc
+ * @requires vm.gc.Shenandoah & !vm.graal.enabled & (vm.bits == "64")
+ *
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:-UseCompressedOops
+ *                   -XX:+UseShenandoahGC
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:-UseCompressedOops
+ *                   -XX:+UseShenandoahGC
+ *                   -Xint
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:-UseCompressedOops
+ *                   -XX:+UseShenandoahGC
+ *                   -XX:-TieredCompilation
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:-UseCompressedOops
+ *                   -XX:+UseShenandoahGC
+ *                   -XX:TieredStopAtLevel=1
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:-UseCompressedOops
+ *                   -XX:+UseShenandoahGC
+ *                   -XX:TieredStopAtLevel=4
+ *                   TestClone
+ */
+
+/*
+ * @test TestClone
+ * @summary Test clone barriers work correctly
+ * @key gc
+ * @requires vm.gc.Shenandoah & !vm.graal.enabled & (vm.bits == "64")
+ *
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:-UseCompressedOops
+ *                   -XX:+UseShenandoahGC
+ *                   -XX:+ShenandoahVerify
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:-UseCompressedOops
+ *                   -XX:+UseShenandoahGC
+ *                   -XX:+ShenandoahVerify
+ *                   -Xint
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:-UseCompressedOops
+ *                   -XX:+UseShenandoahGC
+ *                   -XX:+ShenandoahVerify
+ *                   -XX:-TieredCompilation
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:-UseCompressedOops
+ *                   -XX:+UseShenandoahGC
+ *                   -XX:+ShenandoahVerify
+ *                   -XX:TieredStopAtLevel=1
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:-UseCompressedOops
+ *                   -XX:+UseShenandoahGC
+ *                   -XX:+ShenandoahVerify
+ *                   -XX:TieredStopAtLevel=4
+ *                   TestClone
+ */
+
+/*
+ * @test TestClone
+ * @summary Test clone barriers work correctly
+ * @key gc
+ * @requires vm.gc.Shenandoah & !vm.graal.enabled & (vm.bits == "64")
+ *
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:-UseCompressedOops
+ *                   -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:-UseCompressedOops
+ *                   -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
+ *                   -Xint
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:-UseCompressedOops
+ *                   -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
+ *                   -XX:-TieredCompilation
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:-UseCompressedOops
+ *                   -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
+ *                   -XX:TieredStopAtLevel=1
+ *                   TestClone
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -Xms1g -Xmx1g
+ *                   -XX:-UseCompressedOops
+ *                   -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
+ *                   -XX:TieredStopAtLevel=4
+ *                   TestClone
+ */
+
+
+public class TestClone {
+
+    public static void main(String[] args) throws Exception {
+        for (int i = 0; i < 10000; i++) {
+            Object[] src = new Object[i];
+            for (int c = 0; c < src.length; c++) {
+                src[c] = new Object();
+            }
+            testWith(src);
+        }
+    }
+
+    static void testWith(Object[] src) {
+        Object[] dst = src.clone();
+        int srcLen = src.length;
+        int dstLen = dst.length;
+        if (srcLen != dstLen) {
+            throw new IllegalStateException("Lengths do not match: " + srcLen + " vs " + dstLen);
+        }
+        for (int c = 0; c < src.length; c++) {
+            Object s = src[c];
+            Object d = dst[c];
+            if (s != d) {
+                throw new IllegalStateException("Elements do not match at " + c + ": " + s + " vs " + d);
+            }
+        }
+    }
+}