/* * 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 8191887 * @summary loop cloning misses support for Opaque4 node * @modules java.base/jdk.internal.misc:+open * * @run main/othervm -XX:-BackgroundCompilation TestLoopUnswitching * */ import jdk.internal.misc.Unsafe; import java.lang.reflect.Field; import java.util.Arrays; public class TestLoopUnswitching { 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 test1(A[] arr, boolean flag1, boolean flag2) { int res = 0; for (int i = 0; i < 10; i++) { A a = arr[i]; if (flag1) { // triggers unswitching res += UNSAFE.getInt(a, F_OFFSET); } if (flag2) { // Opaque4 node here is in the loop but If is out of the loop res += UNSAFE.getInt(a, F_OFFSET); break; } res += UNSAFE.getInt(a, F_OFFSET); } return res; } static int test2(A[] arr, boolean flag1, boolean flag2) { int res = 0; for (int i = 0; i < 10; i++) { A a = arr[i]; if (flag1) { // triggers unswitching res += UNSAFE.getInt(a, F_OFFSET); } if (flag2) { // Opaque4 node here is out of the loop but Bool is in the loop res += UNSAFE.getInt(a, F_OFFSET); break; } res += a.f; } return res; } static public void main(String[] args) { A[] arr = new A[1000]; Arrays.fill(arr, new A(0x42)); for (int i = 0; i < 20000; i++) { test1(arr, (i%2) == 0, (i%2) == 0); test2(arr, (i%2) == 0, (i%2) == 0); } } }