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1 /* |
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2 * Copyright 2015 SAP AG. 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 * @test |
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26 * @bug 8080190 |
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27 * @key regression |
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28 * @summary Test that the rotate distance used in the rotate instruction is properly masked with 0x1f |
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29 * @run main/othervm -Xbatch -XX:-UseOnStackReplacement IntRotateWithImmediate |
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30 * @author volker.simonis@gmail.com |
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31 */ |
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32 |
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33 public class IntRotateWithImmediate { |
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34 |
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35 // This is currently the same as Integer.rotateRight() |
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36 static int rotateRight(int i, int distance) { |
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37 // On some architectures (i.e. x86_64 and ppc64) the following computation is |
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38 // matched in the .ad file into a single MachNode which emmits a single rotate |
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39 // machine instruction. It is important that the shift amount is masked to match |
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40 // corresponding immediate width in the native instruction. On x86_64 the rotate |
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41 // left instruction ('rol') encodes an 8-bit immediate while the corresponding |
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42 // 'rotlwi' instruction on Power only encodes a 5-bit immediate. |
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43 return ((i >>> distance) | (i << -distance)); |
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44 } |
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45 |
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46 static int compute(int x) { |
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47 return rotateRight(x, 3); |
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48 } |
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49 |
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50 public static void main(String args[]) { |
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51 int val = 4096; |
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52 |
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53 int firstResult = compute(val); |
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54 |
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55 for (int i = 0; i < 100000; i++) { |
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56 int newResult = compute(val); |
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57 if (firstResult != newResult) { |
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58 throw new InternalError(firstResult + " != " + newResult); |
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59 } |
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60 } |
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61 System.out.println("OK"); |
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62 } |
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63 |
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64 } |