Wed, 04 May 2011 13:12:42 -0700
5091921: Sign flip issues in loop optimizer
Summary: Fix integer overflow problem in the code generated by loop optimizer.
Reviewed-by: never
aoqi@0 | 1 | /* |
aoqi@0 | 2 | * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved. |
aoqi@0 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
aoqi@0 | 4 | * |
aoqi@0 | 5 | * This code is free software; you can redistribute it and/or modify it |
aoqi@0 | 6 | * under the terms of the GNU General Public License version 2 only, as |
aoqi@0 | 7 | * published by the Free Software Foundation. |
aoqi@0 | 8 | * |
aoqi@0 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
aoqi@0 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
aoqi@0 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
aoqi@0 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
aoqi@0 | 13 | * accompanied this code). |
aoqi@0 | 14 | * |
aoqi@0 | 15 | * You should have received a copy of the GNU General Public License version |
aoqi@0 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
aoqi@0 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
aoqi@0 | 18 | * |
aoqi@0 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
aoqi@0 | 20 | * or visit www.oracle.com if you need additional information or have any |
aoqi@0 | 21 | * questions. |
aoqi@0 | 22 | * |
aoqi@0 | 23 | */ |
aoqi@0 | 24 | |
aoqi@0 | 25 | /** |
aoqi@0 | 26 | * @test |
aoqi@0 | 27 | * @bug 6959129 |
aoqi@0 | 28 | * @summary COMPARISON WITH INTEGER.MAX_INT DOES NOT WORK CORRECTLY IN THE CLIENT VM. |
aoqi@0 | 29 | * |
aoqi@0 | 30 | * @run main/othervm -ea Test6959129 |
aoqi@0 | 31 | */ |
aoqi@0 | 32 | |
aoqi@0 | 33 | public class Test6959129 { |
aoqi@0 | 34 | |
aoqi@0 | 35 | public static void main(String[] args) { |
aoqi@0 | 36 | long start = System.currentTimeMillis(); |
aoqi@0 | 37 | int min = Integer.MAX_VALUE-30000; |
aoqi@0 | 38 | int max = Integer.MAX_VALUE; |
aoqi@0 | 39 | long maxmoves = 0; |
aoqi@0 | 40 | try { |
aoqi@0 | 41 | maxmoves = maxMoves(min, max); |
aoqi@0 | 42 | } catch (AssertionError e) { |
aoqi@0 | 43 | System.out.println("Passed"); |
aoqi@0 | 44 | System.exit(95); |
aoqi@0 | 45 | } |
aoqi@0 | 46 | System.out.println("maxMove:" + maxmoves); |
aoqi@0 | 47 | System.out.println("FAILED"); |
aoqi@0 | 48 | System.exit(97); |
aoqi@0 | 49 | } |
aoqi@0 | 50 | /** |
aoqi@0 | 51 | * Imperative implementation that returns the length hailstone moves |
aoqi@0 | 52 | * for a given number. |
aoqi@0 | 53 | */ |
aoqi@0 | 54 | public static long hailstoneLengthImp(long n) { |
aoqi@0 | 55 | long moves = 0; |
aoqi@0 | 56 | while (n != 1) { |
aoqi@0 | 57 | assert n > 1; |
aoqi@0 | 58 | if (isEven(n)) { |
aoqi@0 | 59 | n = n / 2; |
aoqi@0 | 60 | } else { |
aoqi@0 | 61 | n = 3 * n + 1; |
aoqi@0 | 62 | } |
aoqi@0 | 63 | ++moves; |
aoqi@0 | 64 | } |
aoqi@0 | 65 | return moves; |
aoqi@0 | 66 | } |
aoqi@0 | 67 | |
aoqi@0 | 68 | private static boolean isEven(long n) { |
aoqi@0 | 69 | return n % 2 == 0; |
aoqi@0 | 70 | } |
aoqi@0 | 71 | |
aoqi@0 | 72 | /** |
aoqi@0 | 73 | * Returns the maximum length of the hailstone sequence for numbers |
aoqi@0 | 74 | * between min to max. |
aoqi@0 | 75 | * |
aoqi@0 | 76 | * For rec1 - Assume that min is bigger than max. |
aoqi@0 | 77 | */ |
aoqi@0 | 78 | public static long maxMoves(int min, int max) { |
aoqi@0 | 79 | long maxmoves = 0; |
aoqi@0 | 80 | for (int n = min; n <= max; n++) { |
aoqi@0 | 81 | if ((n & 1023) == 0) System.out.println(n); |
aoqi@0 | 82 | long moves = hailstoneLengthImp(n); |
aoqi@0 | 83 | if (moves > maxmoves) { |
aoqi@0 | 84 | maxmoves = moves; |
aoqi@0 | 85 | } |
aoqi@0 | 86 | } |
aoqi@0 | 87 | return maxmoves; |
aoqi@0 | 88 | } |
aoqi@0 | 89 | } |
aoqi@0 | 90 |