view test/compiler/5091921/Test6959129.java @ 12986:1b422ef5288a

8025728: Missing volatile specifier for field G1AllocRegion::_alloc_region Summary: The field G1AllocRegion::_alloc_region needs to be declared volatile as it is used with that intention. Otherwise the compiler may generate the code that reloads the value which might have changed in the meantime, leading to spurious crashes. Reviewed-by: iveresov, simonis, tschatzl Contributed-by: Axel Siebenborn <axel.siebenborn@sap.com>
author tschatzl
date Wed, 23 Oct 2013 10:23:06 +0200
parents bad7ecd0b6ed
children
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/*
 * Copyright (c) 2011, 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 6959129
 * @summary COMPARISON WITH INTEGER.MAX_INT DOES NOT WORK CORRECTLY IN THE CLIENT VM.
 *
 * @run main/othervm -ea Test6959129
 */

public class Test6959129 {

  public static void main(String[] args) {
    long start  = System.currentTimeMillis();
    int min = Integer.MAX_VALUE-30000;
    int max = Integer.MAX_VALUE;
    long maxmoves = 0;
    try {
      maxmoves = maxMoves(min, max);
    } catch (AssertionError e) {
      System.out.println("Passed");
      System.exit(95);
    }
    System.out.println("maxMove:" + maxmoves);
    System.out.println("FAILED");
    System.exit(97);
  }
  /**
   * Imperative implementation that returns the length hailstone moves
   * for a given number.
   */
  public static long hailstoneLengthImp(long n) {
    long moves = 0;
    while (n != 1) {
      assert n > 1;
      if (isEven(n)) {
        n = n / 2;
      } else {
        n = 3 * n + 1;
      }
      ++moves;
    }
    return moves;
  }

  private static boolean isEven(long n) {
    return n % 2 == 0;
  }

  /**
   * Returns the maximum length of the hailstone sequence for numbers
   * between min to max.
   *
   * For rec1 - Assume that min is bigger than max.
   */
  public static long maxMoves(int min, int max) {
    long maxmoves = 0;
    for (int n = min; n <= max; n++) {
      if ((n & 1023) == 0) System.out.println(n);
      long moves = hailstoneLengthImp(n);
      if (moves > maxmoves) {
        maxmoves = moves;
      }
    }
    return maxmoves;
  }
}