8086046: escape analysis generates incorrect code as of B67

Load bypasses arraycopy that sets the value after the ArrayCopyNode is expanded

Reviewed-by: kvn

hotspot/test/compiler/arraycopy/TestLoadBypassArrayCopy.java

@@ -0,0 +1,71 @@
+/*
+ * 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 8086046
+ * @summary load bypasses arraycopy that sets the value after the ArrayCopyNode is expanded
+ * @run main/othervm -XX:-BackgroundCompilation  -XX:-UseOnStackReplacement -XX:CompileCommand=dontinline,TestLoadBypassArrayCopy::test_helper -XX:-TieredCompilation TestLoadBypassArrayCopy
+ *
+ */
+
+public class TestLoadBypassArrayCopy {
+
+    static long i;
+    static boolean test_helper() {
+        i++;
+        if ((i%10) == 0) {
+            return false;
+        }
+        return true;
+    }
+
+    static int test(int[] src, int len, boolean flag) {
+        int[] dest = new int[10];
+        int res = 0;
+        while (test_helper()) {
+            System.arraycopy(src, 0, dest, 0, len);
+            // predicate moved out of loop so control of following
+            // load is not the ArrayCopyNode. Otherwise, if the memory
+            // of the load is changed and the control is set to the
+            // ArrayCopyNode the graph is unschedulable and the test
+            // doesn't fail.
+            if (flag) {
+            }
+            // The memory of this load shouldn't bypass the arraycopy
+            res = dest[0];
+        }
+        return res;
+    }
+
+    static public void main(String[] args) {
+        int[] src = new int[10];
+        src[0] = 0x42;
+        for (int i = 0; i < 20000; i++) {
+            int res = test(src, 10, false);
+            if (res != src[0]) {
+                throw new RuntimeException("test failed");
+            }
+        }
+    }
+}