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/*
* Copyright (C) 2009 Google Inc.
*
* 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.
*/
package com.google.caliper.examples;
import com.google.caliper.Runner;
import com.google.caliper.SimpleBenchmark;
/**
* Measures several candidate implementations for mod().
*/
public class IntModBenchmark extends SimpleBenchmark {
private static final int M = (1 << 16) - 1;
public int timeConditional(int reps) {
int dummy = 5;
for (int i = 0; i < reps; i++) {
dummy += Integer.MAX_VALUE + conditionalMod(dummy, M);
}
return dummy;
}
private static int conditionalMod(int a, int m) {
int r = a % m;
return r < 0 ? r + m : r;
}
public int timeDoubleRemainder(int reps) {
int dummy = 5;
for (int i = 0; i < reps; i++) {
dummy += Integer.MAX_VALUE + doubleRemainderMod(dummy, M);
}
return dummy;
}
private static int doubleRemainderMod(int a, int m) {
return (int) (((a % m) + (long) m) % m);
}
public int timeRightShiftingMod(int reps) {
int dummy = 5;
for (int i = 0; i < reps; i++) {
dummy += Integer.MAX_VALUE + rightShiftingMod(dummy, M);
}
return dummy;
}
private static int rightShiftingMod(int a, int m) {
long r = a % m;
return (int) (r + ((r >> 63) & m));
}
public int timeLeftShiftingMod(int reps) {
int dummy = 5;
for (int i = 0; i < reps; i++) {
dummy += Integer.MAX_VALUE + leftShiftingMod(dummy, M);
}
return dummy;
}
private static int leftShiftingMod(int a, int m) {
return (int) ((a + (((long) m) << 32)) % m);
}
public int timeWrongMod(int reps) {
int dummy = 5;
for (int i = 0; i < reps; i++) {
dummy += Integer.MAX_VALUE + dummy % M;
}
return dummy;
}
// TODO: remove this from all examples when IDE plugins are ready
public static void main(String[] args) throws Exception {
Runner.main(IntModBenchmark.class, args);
}
}
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