test/hotspot/jtreg/compiler/unsafe/TestSplitIf.java
changeset 47820 1bc021ddeae0
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/compiler/unsafe/TestSplitIf.java	Thu Nov 09 12:43:13 2017 -0800
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2017, 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
+ * @bug 8186125
+ * @summary cast before unsafe access moved in dominating null check null path causes crash
+ * @modules java.base/jdk.internal.misc:+open
+ *
+ * @run main/othervm -XX:-BackgroundCompilation TestSplitIf
+ *
+ */
+
+import jdk.internal.misc.Unsafe;
+import java.lang.reflect.Field;
+
+public class TestSplitIf {
+
+    static final jdk.internal.misc.Unsafe UNSAFE = Unsafe.getUnsafe();
+    static final long F_OFFSET;
+
+    static class A {
+        int f;
+        A(int f) {
+            this.f = f;
+        }
+    }
+
+    static {
+        try {
+            Field fField = A.class.getDeclaredField("f");
+            F_OFFSET = UNSAFE.objectFieldOffset(fField);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    static int test(A a1, A a2, boolean flag1) {
+        boolean flag2;
+        int f = 0;
+        A a = null;
+        if (flag1) {
+            flag2 = true;
+            a = a1;
+        } else {
+            flag2 = false;
+            a = a2;
+        }
+        if (flag2) {
+            f = UNSAFE.getInt(a, F_OFFSET);
+        } else {
+            f = UNSAFE.getInt(a, F_OFFSET);
+        }
+        return f;
+    }
+
+    static public void main(String[] args) {
+        A a = new A(0x42);
+        for (int i = 0; i < 20000; i++) {
+            test(a, a, (i % 2) == 0);
+        }
+    }
+
+}