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 8078426
  28  * @summary split if finds predicates on several incoming paths when unswitched's loops are optimized out
  29  *
  30  * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:-UseOnStackReplacement
  31  *                   -XX:-BackgroundCompilation -XX:-UseCompressedOops
  32  *                   compiler.loopopts.TestSplitIfUnswitchedLoopsEliminated
  33  */
  34 
  35 package compiler.loopopts;
  36 
  37 public class TestSplitIfUnswitchedLoopsEliminated {
  38 
  39     static class A {
  40         int f;
  41     }
  42 
  43     static A aa = new A();
  44     static A aaa = new A();
  45 
  46     static int test_helper(int stop, boolean unswitch) {
  47         A a = null;
  48         for (int i = 3; i < 10; i++) {
  49             if (unswitch) {
  50                 a = null;
  51             } else {
  52                 a = aa;
  53                 int v = a.f;
  54             }
  55         }
  56         if (stop != 4) {
  57             a = aaa;
  58         }
  59         if (a != null) {
  60             return a.f;
  61         }
  62         return 0;
  63     }
  64 
  65     static int test(boolean unswitch) {
  66         int stop = 1;
  67         for (; stop < 3; stop *= 4) {
  68         }
  69         return test_helper(stop, unswitch);
  70     }
  71 
  72     public static void main(String[] args) {
  73         for (int i = 0; i < 20000; i++) {
  74             test_helper(10, i%2 == 0);
  75             test(i%2 == 0);
  76         }
  77     }
  78 }