1 /*
   2  * Copyright (c) 2011, 2012, 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 package org.graalvm.compiler.jtt.hotspot;
  24 
  25 import org.junit.Test;
  26 
  27 import org.graalvm.compiler.jtt.JTTTest;
  28 
  29 public class Test6959129 extends JTTTest {
  30 
  31     public static long test() {
  32         int min = Integer.MAX_VALUE - 30000;
  33         int max = Integer.MAX_VALUE;
  34         return maxMoves(min, max);
  35     }
  36 
  37     /**
  38      * Imperative implementation that returns the length hailstone moves for a given number.
  39      */
  40     public static long hailstoneLengthImp(long n2) {
  41         long n = n2;
  42         long moves = 0;
  43         while (n != 1) {
  44             if (n <= 1) {
  45                 throw new IllegalStateException();
  46             }
  47             if (isEven(n)) {
  48                 n = n / 2;
  49             } else {
  50                 n = 3 * n + 1;
  51             }
  52             ++moves;
  53         }
  54         return moves;
  55     }
  56 
  57     private static boolean isEven(long n) {
  58         return n % 2 == 0;
  59     }
  60 
  61     /**
  62      * Returns the maximum length of the hailstone sequence for numbers between min to max.
  63      *
  64      * For rec1 - Assume that min is bigger than max.
  65      */
  66     public static long maxMoves(int min, int max) {
  67         long maxmoves = 0;
  68         for (int n = min; n <= max; n++) {
  69             long moves = hailstoneLengthImp(n);
  70             if (moves > maxmoves) {
  71                 maxmoves = moves;
  72             }
  73         }
  74         return maxmoves;
  75     }
  76 
  77     @Test(timeout = 20000)
  78     public void run0() throws Throwable {
  79         runTest("test");
  80     }
  81 
  82 }