hotspot/test/compiler/loopopts/TestDeadBackbranchArrayAccess.java
author roland
Thu, 13 Nov 2014 09:19:46 +0100
changeset 27708 8a8710cb8fc4
child 40059 c2304140ed64
permissions -rw-r--r--
8054478: C2: Incorrectly compiled char[] array access crashes JVM Summary: dead backbranch in main loop results in erroneous array access Reviewed-by: kvn, iveresov
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/*
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 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * This code is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 only, as
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 * published by the Free Software Foundation.
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 *
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * accompanied this code).
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 *
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 * You should have received a copy of the GNU General Public License version
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 *
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 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * or visit www.oracle.com if you need additional information or have any
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 * questions.
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 *
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 */
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/**
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 * @test
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 * @bug 8054478
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 * @summary dead backbranch in main loop results in erroneous array access
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 * @run main/othervm -XX:CompileOnly=TestDeadBackbranchArrayAccess -Xcomp TestDeadBackbranchArrayAccess
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 *
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 */
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public class TestDeadBackbranchArrayAccess {
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    static char[] pattern0 = {0};
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    static char[] pattern1 = {1};
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    static void test(char[] array) {
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        if (pattern1 == null) return;
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        int i = 0;
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        int pos = 0;
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        char c = array[pos];
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        while (i >= 0 && (c == pattern0[i] || c == pattern1[i])) {
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            i--;
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            pos--;
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            if (pos != -1) {
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                c = array[pos];
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            }
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        }
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    }
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    public static void main(String[] args) {
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        for (int i = 0; i < 1000000; i++) {
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            test(new char[1]);
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        }
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    }
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}