64 lines
2.0 KiB
Java
64 lines
2.0 KiB
Java
/*
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* Copyright (c) 2022, Arm Limited. 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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* @test
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* @bug 8283408
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* @summary Fill a byte array with Java Unsafe API
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* @run main/othervm -XX:+OptimizeFill compiler.loopopts.FillArrayWithUnsafe
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*/
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package compiler.loopopts;
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import java.lang.reflect.Field;
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import sun.misc.Unsafe;
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public class FillArrayWithUnsafe {
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private static Unsafe unsafe;
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public static void main(String[] args) throws Exception {
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Class klass = Unsafe.class;
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Field field = klass.getDeclaredField("theUnsafe");
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field.setAccessible(true);
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unsafe = (Unsafe) field.get(null);
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byte[] buffer;
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// Make sure method newByteArray is compiled by C2
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for (int i = 0; i < 50000; i++) {
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buffer = newByteArray(100, (byte) 0x80);
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}
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}
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public static byte[] newByteArray(int size, byte val) {
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byte[] arr = new byte[size];
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int offset = unsafe.arrayBaseOffset(byte[].class);
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for (int i = offset; i < offset + size; i++) {
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unsafe.putByte(arr, i, val);
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}
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return arr;
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}
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}
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