8134321: tools/pack200/Pack200Test.java crashes in the VM PIT jdk9 b79

Code that capture field values of eliminated allocation at a safepoint when there's an arraycopy behind a Phi is broken

Reviewed-by: kvn

hotspot/src/share/vm/opto/macro.cpp

@@ -521,6 +521,9 @@ Node *PhaseMacroExpand::value_from_mem_phi(Node *mem, BasicType ft, const Type *
         return NULL;
       } else if (val->is_ArrayCopy()) {
         Node* res = make_arraycopy_load(val->as_ArrayCopy(), offset, val->in(0), ft, phi_type, alloc);
+        if (res == NULL) {
+          return NULL;
+        }
         values.at_put(j, res);
       } else {
 #ifdef ASSERT

hotspot/test/compiler/arraycopy/TestEliminatedArrayCopyPhi.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2015, 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 8134321
+ * @summary Code that capture field values of eliminated allocation at a safepoint when there's an arraycopy behind a Phi is broken
+ * @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement TestEliminatedArrayCopyPhi
+ *
+ */
+
+public class TestEliminatedArrayCopyPhi {
+
+    static int[] escaped;
+
+    static void test(int[] src, boolean flag1, boolean flag2) {
+        int[] array = new int[10];
+        if (flag1) {
+            System.arraycopy(src, 0, array, 0, src.length);
+        } else {
+        }
+
+        if (flag2) {
+            // never taken
+            escaped = array;
+        }
+    }
+
+    public static void main(String[] args) {
+        int[] src = new int[10];
+        for (int i = 0; i < 20000; i++) {
+            test(src, (i % 2) == 0, false);
+        }
+    }
+}