| /* |
| * Copyright (c) 2009, 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 6843752 |
| * @summary missing code for an anti-dependent Phi in GCM |
| * |
| * @run main/othervm -Xbatch compiler.c2.Test6843752 |
| */ |
| |
| package compiler.c2; |
| |
| public class Test6843752 { |
| |
| Item list; |
| |
| static class Item { |
| public Item next; |
| public Item prev; |
| public boolean remove; |
| |
| Item(boolean r) { remove = r; } |
| } |
| |
| private void linkIn(Item item) { |
| Item head = list; |
| if (head == null) { |
| item.next = item; |
| item.prev = item; |
| list = item; |
| } else { |
| item.next = head; |
| item.prev = head.prev; |
| head.prev.next = item; |
| head.prev = item; |
| } |
| } |
| |
| private void linkOut(Item item) { |
| Item head = list; |
| if (item.next == item) { |
| list = null; |
| } else { |
| item.prev.next = item.next; |
| item.next.prev = item.prev; |
| if (head == item) { |
| list = item.next; |
| } |
| } |
| item.next = null; |
| item.prev = null; // this is the null pointer we are seeing |
| } |
| |
| private void removeItems(int numItems) { |
| Item item = list; |
| if (item == null) { |
| return; |
| } |
| Item last = item.prev; |
| boolean done = false; |
| while (!done && numItems > 1) { |
| // the original code "done = (item == last);" triggered an infinite loop |
| // and was changed slightly in order to produce an exception instead. |
| done = (item.next == last.next); |
| item = item.next; |
| if (item.prev.remove) { |
| linkOut(item.prev); |
| } |
| } |
| } |
| |
| public void perform(int numItems) { |
| for (int i = 0; i < numItems; i++) { |
| linkIn(new Item(i == 0)); |
| } |
| removeItems(numItems); |
| list = null; |
| } |
| |
| static public void main(String[] args) { |
| int caseCnt = 0; |
| Test6843752 bj = new Test6843752(); |
| try { |
| for (; caseCnt < 500000;) { |
| int numItems = (++caseCnt % 2); |
| if ((caseCnt % 64) == 0) { |
| numItems = 5; |
| } |
| bj.perform(numItems); |
| if ((caseCnt % 100000) == 0) { |
| System.out.println("successfully performed " + caseCnt + " cases"); |
| } |
| } |
| } catch (Exception e) { |
| System.out.println("ERROR: crashed during case " + caseCnt); |
| e.printStackTrace(System.out); |
| System.exit(97); |
| } |
| } |
| } |
| |