--- a/hotspot/src/share/vm/adlc/formssel.cpp	Sat Oct 29 01:09:42 2016 +0200
+++ b/hotspot/src/share/vm/adlc/formssel.cpp	Thu Oct 13 12:27:39 2016 +0200
@@ -776,19 +776,21 @@
 // This instruction captures the machine-independent bottom_type
 // Expected use is for pointer vs oop determination for LoadP
 bool InstructForm::captures_bottom_type(FormDict &globals) const {
-  if( _matrule && _matrule->_rChild &&
-       (!strcmp(_matrule->_rChild->_opType,"CastPP")       ||  // new result type
-        !strcmp(_matrule->_rChild->_opType,"CastX2P")      ||  // new result type
-        !strcmp(_matrule->_rChild->_opType,"DecodeN")      ||
-        !strcmp(_matrule->_rChild->_opType,"EncodeP")      ||
-        !strcmp(_matrule->_rChild->_opType,"DecodeNKlass") ||
-        !strcmp(_matrule->_rChild->_opType,"EncodePKlass") ||
-        !strcmp(_matrule->_rChild->_opType,"LoadN")        ||
-        !strcmp(_matrule->_rChild->_opType,"LoadNKlass")   ||
-        !strcmp(_matrule->_rChild->_opType,"CreateEx")     ||  // type of exception
-        !strcmp(_matrule->_rChild->_opType,"CheckCastPP")  ||
-        !strcmp(_matrule->_rChild->_opType,"GetAndSetP")   ||
-        !strcmp(_matrule->_rChild->_opType,"GetAndSetN")) )  return true;
+  if (_matrule && _matrule->_rChild &&
+      (!strcmp(_matrule->_rChild->_opType,"CastPP")       ||  // new result type
+       !strcmp(_matrule->_rChild->_opType,"CastX2P")      ||  // new result type
+       !strcmp(_matrule->_rChild->_opType,"DecodeN")      ||
+       !strcmp(_matrule->_rChild->_opType,"EncodeP")      ||
+       !strcmp(_matrule->_rChild->_opType,"DecodeNKlass") ||
+       !strcmp(_matrule->_rChild->_opType,"EncodePKlass") ||
+       !strcmp(_matrule->_rChild->_opType,"LoadN")        ||
+       !strcmp(_matrule->_rChild->_opType,"LoadNKlass")   ||
+       !strcmp(_matrule->_rChild->_opType,"CreateEx")     ||  // type of exception
+       !strcmp(_matrule->_rChild->_opType,"CheckCastPP")  ||
+       !strcmp(_matrule->_rChild->_opType,"GetAndSetP")   ||
+       !strcmp(_matrule->_rChild->_opType,"GetAndSetN")   ||
+       !strcmp(_matrule->_rChild->_opType,"CompareAndExchangeP") ||
+       !strcmp(_matrule->_rChild->_opType,"CompareAndExchangeN")))  return true;
   else if ( is_ideal_load() == Form::idealP )                return true;
   else if ( is_ideal_store() != Form::none  )                return true;
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/compiler/intrinsics/unsafe/TestCAEAntiDep.java	Thu Oct 13 12:27:39 2016 +0200
@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2016, 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 8167298
+ * @summary Unsafe.compareAndExchangeObject should keep track of returned type after matching
+ * @modules java.base/jdk.internal.misc
+ * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:-UseCompressedOops TestCAEAntiDep
+ *
+ */
+
+import java.lang.reflect.Field;
+import jdk.internal.misc.Unsafe;
+
+public class TestCAEAntiDep {
+    static final jdk.internal.misc.Unsafe UNSAFE = Unsafe.getUnsafe();
+    static final long O_OFFSET;
+
+    static class C {
+        int f1;
+    }
+
+    C o = new C();
+
+    static {
+        try {
+            Field oField = TestCAEAntiDep.class.getDeclaredField("o");
+            O_OFFSET = UNSAFE.objectFieldOffset(oField);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    static int m(TestCAEAntiDep test, Object expected, Object x) {
+        C old = (C)UNSAFE.compareAndExchangeObjectVolatile(test, O_OFFSET, expected, x);
+        int res = old.f1;
+        old.f1 = 0x42;
+        return res;
+    }
+
+    static public void main(String[] args) {
+        TestCAEAntiDep test = new TestCAEAntiDep();
+        for (int i = 0; i < 20000; i++) {
+            m(test, test.o, test.o);
+        }
+    }
+}