jdk-24/test/micro/org/openjdk/bench/java/lang/ArrayCopyAlignedLarge.java
steveatgh 82967f45db 8310159: Bulk copy with Unsafe::arrayCopy is slower compared to memcpy
Co-authored-by: Maurizio Cimadamore <mcimadamore@openjdk.org>
Reviewed-by: thartmann, jbhateja, sviswanathan
2023-11-27 17:35:39 +00:00

71 lines
2.3 KiB
Java

/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
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*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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package org.openjdk.bench.java.lang;
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Fork;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Param;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Warmup;
import java.util.concurrent.TimeUnit;
/**
* Benchmark measuring aligned System.arraycopy.
*/
@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@State(Scope.Thread)
@Warmup(iterations = 10, time = 1)
@Measurement(iterations = 5, time = 1)
@Fork(value = 3)
public class ArrayCopyAlignedLarge {
@Param({"100000", "1000000", "2000000", "5000000", "10000000"})
int length;
int fromPos, toPos;
byte[] fromByteArr, toByteArr;
@Setup
public void setup() {
// Both positions aligned
fromPos = 0;
toPos = 0;
fromByteArr = new byte[length];
toByteArr = new byte[length];
}
@Benchmark
public void testByte() {
System.arraycopy(fromByteArr, fromPos, toByteArr, toPos, length);
}
}