71 lines
2.1 KiB
Java
71 lines
2.1 KiB
Java
/*
|
|
* Copyright (c) 2019, 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 8220416
|
|
* @summary This test uses a class pointer comparison optimization which was not applied anymore since JDK-6964458 resulting in a better IR.
|
|
*
|
|
* @run main/othervm -Xbatch -XX:-TieredCompilation -XX:+IgnoreUnrecognizedVMOptions -XX:+AlwaysIncrementalInline
|
|
* -XX:CompileOnly=compiler.c2.CompareKlassPointersTest::test compiler.c2.CompareKlassPointersTest
|
|
*/
|
|
|
|
package compiler.c2;
|
|
|
|
|
|
|
|
public class CompareKlassPointersTest {
|
|
|
|
static A a;
|
|
|
|
public static void main(String[] args) {
|
|
a = new C();
|
|
for (int i = 0; i < 10_000; i++) {
|
|
test();
|
|
}
|
|
}
|
|
|
|
public static int test() {
|
|
Object a = getA();
|
|
|
|
/*
|
|
* This check is now optimized away which was not the case before anymore since JDK-6964458:
|
|
* The klass pointer comparison optimization sees that the check is always false since a and B are always unrelated klasses
|
|
*/
|
|
if (a instanceof B) {
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
private static Object getA() {
|
|
return a;
|
|
}
|
|
}
|
|
|
|
class A { }
|
|
|
|
class B { }
|
|
|
|
class C extends A { }
|