hotspot/test/compiler/5091921/Test6897150.java
changeset 9446 748a37b25d10
equal deleted inserted replaced
9445:af37395bda58 9446:748a37b25d10
       
     1 /*
       
     2  * Copyright (c) 2011, 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 6897150
       
    28  * @summary Hotspot optimises away a valid loop
       
    29  *
       
    30  * @run main Test6897150
       
    31  */
       
    32 
       
    33 // Should be compiled with javac from JDK1.3 to get bytecode which shows the problem.
       
    34 public class Test6897150 {
       
    35     public static void main(String[] args) {
       
    36         // This works
       
    37         loopAndPrint(Integer.MAX_VALUE -1);
       
    38         // This doesn't
       
    39         loopAndPrint(Integer.MAX_VALUE);
       
    40     }
       
    41 
       
    42     static void verify(int max, int a) {
       
    43         if ( a != (max - 1)) {
       
    44             System.out.println("Expected: " + (max - 1));
       
    45             System.out.println("Actual  : " + a);
       
    46             System.exit(97);
       
    47         }
       
    48     }
       
    49     static void loopAndPrint(int max) {
       
    50         int a = -1;
       
    51         int i = 1;
       
    52         for (; i < max; i++) {
       
    53             a = i;
       
    54         }
       
    55         verify(max, a);
       
    56     }
       
    57 }
       
    58