3345
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1 /*
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2 * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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4 *
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5 * This code is free software; you can redistribute it and/or modify it
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6 * under the terms of the GNU General Public License version 2 only, as
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7 * published by the Free Software Foundation.
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8 *
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9 * This code is distributed in the hope that it will be useful, but WITHOUT
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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12 * version 2 for more details (a copy is included in the LICENSE file that
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13 * accompanied this code).
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14 *
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15 * You should have received a copy of the GNU General Public License version
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16 * 2 along with this work; if not, write to the Free Software Foundation,
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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18 *
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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20 * or visit www.oracle.com if you need additional information or have any
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21 * questions.
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22 *
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23 */
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24
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25 /**
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26 * @test
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27 * @bug 6897150
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28 * @summary Hotspot optimises away a valid loop
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29 *
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30 * @run main Test6897150
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31 */
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32
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33 // Should be compiled with javac from JDK1.3 to get bytecode which shows the problem.
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34 public class Test6897150 {
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35 public static void main(String[] args) {
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36 // This works
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37 loopAndPrint(Integer.MAX_VALUE -1);
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38 // This doesn't
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39 loopAndPrint(Integer.MAX_VALUE);
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40 }
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41
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42 static void verify(int max, int a) {
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43 if ( a != (max - 1)) {
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44 System.out.println("Expected: " + (max - 1));
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45 System.out.println("Actual : " + a);
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46 System.exit(97);
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47 }
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48 }
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49 static void loopAndPrint(int max) {
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50 int a = -1;
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51 int i = 1;
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52 for (; i < max; i++) {
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53 a = i;
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54 }
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55 verify(max, a);
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56 }
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57 }
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58
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