1 /* 2 * Copyright (c) 2016, Oracle and/or its affiliates. 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 8159016 27 * @summary Tests correct dominator information after over-unrolling a loop. 28 * @requires vm.gc == "Parallel" | vm.gc == "null" 29 * 30 * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -Xcomp -XX:-TieredCompilation 31 * -XX:-UseG1GC -XX:+UseParallelGC 32 * compiler.loopopts.TestOverunrolling 33 */ 34 35 package compiler.loopopts; 36 37 public class TestOverunrolling { 38 39 public static Object test(int arg) { 40 Object arr[] = new Object[3]; 41 int lim = (arg & 3); 42 // The pre loop is executed for one iteration, initializing p[0]. 43 // The main loop is unrolled twice, initializing p[1], p[2], p[3] and p[4]. 44 // The p[3] and p[4] stores are always out of bounds and removed. However, 45 // C2 is unable to remove the "over-unrolled", dead main loop. As a result, 46 // there is a control path from the main loop to the post loop without a 47 // memory path (because the last store was replaced by TOP). We crash 48 // because we use a memory edge from a non-dominating region. 49 for (int i = 0; i < lim; ++i) { 50 arr[i] = new Object(); 51 } 52 // Avoid EA 53 return arr; 54 } 55 56 public static void main(String args[]) { 57 for (int i = 0; i < 42; ++i) { 58 test(i); 59 } 60 } 61 } 62 | 1 /* 2 * Copyright (c) 2016, 2018, Oracle and/or its affiliates. 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 8159016 8202949 27 * @summary Tests correct dominator information after over-unrolling a loop. 28 * @requires vm.gc == "Parallel" | vm.gc == "null" 29 * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:+UnlockExperimentalVMOptions 30 * -Xcomp -XX:-TieredCompilation -XX:-UseSwitchProfiling 31 * -XX:-UseG1GC -XX:+UseParallelGC compiler.loopopts.TestOverunrolling 32 */ 33 34 package compiler.loopopts; 35 36 public class TestOverunrolling { 37 38 public static Object test1(int arg) { 39 Object arr[] = new Object[3]; 40 int lim = (arg & 3); 41 // The pre loop is executed for one iteration, initializing p[0]. 42 // The main loop is unrolled twice, initializing p[1], p[2], p[3] and p[4]. 43 // The p[3] and p[4] stores are always out of bounds and removed. However, 44 // C2 is unable to remove the "over-unrolled", dead main loop. As a result, 45 // there is a control path from the main loop to the post loop without a 46 // memory path (because the last store was replaced by TOP). We crash 47 // because we use a memory edge from a non-dominating region. 48 for (int i = 0; i < lim; ++i) { 49 arr[i] = new Object(); 50 } 51 // Avoid EA 52 return arr; 53 } 54 55 public static long lFld = 0; 56 public static volatile double dFld = 0; 57 58 public static void test2() { 59 int iArr[] = new int[10]; 60 // The inner for-loop is overunrolled because we fail to determine 61 // the constant lower and upper bound (6,8]. After unrolling multiple times, 62 // the range check dependent CastII/ConvI2L emitted for the iArr access become 63 // TOP because index 'j' is out of bounds. As a result, the memory graph is 64 // corrupted with memory consuming nodes still being reachable because the dead 65 // loop is not (yet) removed (Opaque1 nodes are still guarding the bounds). 66 for (int i = 6; i < 10; i++) { 67 for (int j = 8; j > i; j--) { 68 int k = 1; 69 do { 70 iArr[j] = 0; 71 switch (k) { 72 case 1: 73 lFld = 0; 74 break; 75 case 10: 76 dFld = 0; 77 break; 78 } 79 } while (++k < 1); 80 } 81 } 82 } 83 84 public static void main(String args[]) { 85 for (int i = 0; i < 42; ++i) { 86 test1(i); 87 } 88 test2(); 89 } 90 } 91 |