1 /* 2 * Copyright (c) 2017, Red Hat, Inc. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /** 25 * @test 26 * @bug 8191887 27 * @summary loop cloning misses support for Opaque4 node 28 * @modules java.base/jdk.internal.misc:+open 29 * 30 * @run main/othervm -XX:-BackgroundCompilation TestLoopUnswitching 31 * 32 */ 33 34 import jdk.internal.misc.Unsafe; 35 import java.lang.reflect.Field; 36 import java.util.Arrays; 37 38 public class TestLoopUnswitching { 39 40 static final jdk.internal.misc.Unsafe UNSAFE = Unsafe.getUnsafe(); 41 static final long F_OFFSET; 42 43 static class A { 44 int f; A(int f)45 A(int f) { 46 this.f = f; 47 } 48 } 49 50 static { 51 try { 52 Field fField = A.class.getDeclaredField("f"); 53 F_OFFSET = UNSAFE.objectFieldOffset(fField); 54 } catch (Exception e) { 55 throw new RuntimeException(e); 56 } 57 } 58 test1(A[] arr, boolean flag1, boolean flag2)59 static int test1(A[] arr, boolean flag1, boolean flag2) { 60 int res = 0; 61 for (int i = 0; i < 10; i++) { 62 A a = arr[i]; 63 if (flag1) { // triggers unswitching 64 res += UNSAFE.getInt(a, F_OFFSET); 65 } 66 if (flag2) { 67 // Opaque4 node here is in the loop but If is out of the loop 68 res += UNSAFE.getInt(a, F_OFFSET); 69 break; 70 } 71 res += UNSAFE.getInt(a, F_OFFSET); 72 } 73 return res; 74 } 75 test2(A[] arr, boolean flag1, boolean flag2)76 static int test2(A[] arr, boolean flag1, boolean flag2) { 77 int res = 0; 78 for (int i = 0; i < 10; i++) { 79 A a = arr[i]; 80 if (flag1) { // triggers unswitching 81 res += UNSAFE.getInt(a, F_OFFSET); 82 } 83 if (flag2) { 84 // Opaque4 node here is out of the loop but Bool is in the the loop 85 res += UNSAFE.getInt(a, F_OFFSET); 86 break; 87 } 88 res += a.f; 89 } 90 return res; 91 } 92 main(String[] args)93 static public void main(String[] args) { 94 A[] arr = new A[1000]; 95 Arrays.fill(arr, new A(0x42)); 96 for (int i = 0; i < 20000; i++) { 97 test1(arr, (i%2) == 0, (i%2) == 0); 98 test2(arr, (i%2) == 0, (i%2) == 0); 99 } 100 } 101 102 } 103