1 /*
   2  * Copyright (c) 2015, 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 /**
  26  * @test
  27  * @bug 8072753
  28  * @summary Inner loop induction variable increment occurs before compare which causes integer overflow
  29  * @run main/othervm CountedLoopProblem
  30  *
  31  */
  32 
  33 import java.util.*;
  34 
  35 public class CountedLoopProblem {
  36     public static void main(String[] args) throws Exception {
  37         Random r = new Random(42);
  38         int x = 0;
  39         try {
  40             StringBuilder sb = new StringBuilder();
  41             for(int i = 0; i < 1000000; ++i) {
  42                 int v = Math.abs(r.nextInt());
  43                 sb.append('+').append(v).append('\n');
  44                 x += v;
  45                 // To trigger the problem we must OSR in the following loop
  46                 // To make the problem 100% reproducible run with -XX:-TieredCompilation -XX:OSROnlyBCI=62
  47                 while(x < 0) x += 1000000000;
  48                 sb.append('=').append(x).append('\n');
  49             }
  50             if (sb.toString().hashCode() != 0xaba94591) {
  51                 throw new Exception("Unexpected result");
  52             }
  53         } catch(OutOfMemoryError e) {
  54             // small heap, ignore
  55         }
  56     }
  57 }
  58