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/*
* Copyright (C) 2015 Linaro Limited. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
/*
* Description: Tracks performance of looped array access to Java Objects.
* BitSet is an arbitrary choice. 1024 pool and update list
* sizes showed benefits when prefetching 8 references ahead
* during looped array access. Other benchmarks for different
* and mixed Object sizes would be beneficial.
* Main Focus: Looped array access to semi-random memory access patterns.
* Secondary Focus:
*
*/
package art_benchmarks.micro;
import java.util.BitSet;
import java.util.Random;
public class PrefetchLoopedArrayAccess {
private static final Random rnd = new Random(0);
private static final int POOL_Size = 1024;
private static final int UPDATE_Size = 1024;
private BitSet[] bits;
private BitSet[] updateList;
{
initBitSets();
initUpdateList();
}
private void initUpdateList() {
updateList = new BitSet[UPDATE_Size];
for (int i = 0; i < UPDATE_Size; i++) {
updateList[i] = bits[rnd.nextInt(POOL_Size)];
}
}
private void initBitSets() {
bits = new BitSet[POOL_Size];
for (int i = 0; i < POOL_Size; i++) {
bits[i] = new BitSet();
}
}
private void updateBitSets() {
for (int i = 0; i < UPDATE_Size; i++) {
updateList[i].set(7);
}
}
public void timeRun(int iterations) {
for (int i = 0; i < iterations; i++) {
updateBitSets();
}
}
public static void main(String[] args) {
PrefetchLoopedArrayAccess obj = new PrefetchLoopedArrayAccess();
long before = System.currentTimeMillis();
obj.timeRun(22000);
long after = System.currentTimeMillis();
System.out.println("art_benchmarks/micro/PrefetchLoopedArrayAccess: " + (after - before));
}
}
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