1 /*
2  * Copyright (C) 2011 The Guava Authors
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.google.common.math;
18 
19 import static com.google.common.math.MathBenchmarking.ARRAY_MASK;
20 import static com.google.common.math.MathBenchmarking.ARRAY_SIZE;
21 import static com.google.common.math.MathBenchmarking.RANDOM_SOURCE;
22 import static com.google.common.math.MathBenchmarking.randomDouble;
23 import static com.google.common.math.MathBenchmarking.randomPositiveDouble;
24 
25 import com.google.caliper.BeforeExperiment;
26 import com.google.caliper.Benchmark;
27 
28 /**
29  * Tests for the non-rounding methods of {@code DoubleMath}.
30  *
31  * @author Louis Wasserman
32  */
33 public class DoubleMathBenchmark {
34   private static final double[] positiveDoubles = new double[ARRAY_SIZE];
35   private static final int[] factorials = new int[ARRAY_SIZE];
36   private static final double [] doubles = new double[ARRAY_SIZE];
37 
38   @BeforeExperiment
setUp()39   void setUp() {
40     for (int i = 0; i < ARRAY_SIZE; i++) {
41       positiveDoubles[i] = randomPositiveDouble();
42       doubles[i] = randomDouble(Long.SIZE);
43       factorials[i] = RANDOM_SOURCE.nextInt(100);
44     }
45   }
46 
log2(int reps)47   @Benchmark long log2(int reps) {
48     long tmp = 0;
49     for (int i = 0; i < reps; i++) {
50       int j = i & ARRAY_MASK;
51       tmp += Double.doubleToRawLongBits(DoubleMath.log2(positiveDoubles[j]));
52     }
53     return tmp;
54   }
55 
factorial(int reps)56   @Benchmark long factorial(int reps) {
57     long tmp = 0;
58     for (int i = 0; i < reps; i++) {
59       int j = i & ARRAY_MASK;
60       tmp += Double.doubleToRawLongBits(DoubleMath.factorial(factorials[j]));
61     }
62     return tmp;
63   }
64 
isMathematicalInteger(int reps)65   @Benchmark int isMathematicalInteger(int reps) {
66     int tmp = 0;
67     for (int i = 0; i < reps; i++) {
68       int j = i & ARRAY_MASK;
69       if (DoubleMath.isMathematicalInteger(doubles[j])) {
70         tmp++;
71       }
72     }
73     return tmp;
74   }
75 
isPowerOfTwo(int reps)76   @Benchmark int isPowerOfTwo(int reps) {
77     int tmp = 0;
78     for (int i = 0; i < reps; i++) {
79       int j = i & ARRAY_MASK;
80       if (DoubleMath.isPowerOfTwo(doubles[j])) {
81         tmp++;
82       }
83     }
84     return tmp;
85   }
86 }
87