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comparison test/compiler/5091921/Test6959129.java @ 3345:bad7ecd0b6ed

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5091921: Sign flip issues in loop optimizer Summary: Fix integer overflow problem in the code generated by loop optimizer. Reviewed-by: never
author kvn
date Wed, 04 May 2011 13:12:42 -0700
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3344:0139aac70fb5 3345:bad7ecd0b6ed
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 6959129
28 * @summary COMPARISON WITH INTEGER.MAX_INT DOES NOT WORK CORRECTLY IN THE CLIENT VM.
29 *
30 * @run main/othervm -ea Test6959129
31 */
32
33 public class Test6959129 {
34
35 public static void main(String[] args) {
36 long start = System.currentTimeMillis();
37 int min = Integer.MAX_VALUE-30000;
38 int max = Integer.MAX_VALUE;
39 long maxmoves = 0;
40 try {
41 maxmoves = maxMoves(min, max);
42 } catch (AssertionError e) {
43 System.out.println("Passed");
44 System.exit(95);
45 }
46 System.out.println("maxMove:" + maxmoves);
47 System.out.println("FAILED");
48 System.exit(97);
49 }
50 /**
51 * Imperative implementation that returns the length hailstone moves
52 * for a given number.
53 */
54 public static long hailstoneLengthImp(long n) {
55 long moves = 0;
56 while (n != 1) {
57 assert n > 1;
58 if (isEven(n)) {
59 n = n / 2;
60 } else {
61 n = 3 * n + 1;
62 }
63 ++moves;
64 }
65 return moves;
66 }
67
68 private static boolean isEven(long n) {
69 return n % 2 == 0;
70 }
71
72 /**
73 * Returns the maximum length of the hailstone sequence for numbers
74 * between min to max.
75 *
76 * For rec1 - Assume that min is bigger than max.
77 */
78 public static long maxMoves(int min, int max) {
79 long maxmoves = 0;
80 for (int n = min; n <= max; n++) {
81 if ((n & 1023) == 0) System.out.println(n);
82 long moves = hailstoneLengthImp(n);
83 if (moves > maxmoves) {
84 maxmoves = moves;
85 }
86 }
87 return maxmoves;
88 }
89 }
90