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.randomDouble;
22 import static com.google.common.math.MathBenchmarking.randomPositiveDouble;
23 
24 import com.google.caliper.BeforeExperiment;
25 import com.google.caliper.Benchmark;
26 import com.google.caliper.Param;
27 import com.google.common.math.DoubleMath;
28 
29 import java.math.RoundingMode;
30 
31 /**
32  * Benchmarks for the rounding methods of {@code DoubleMath}.
33  *
34  * @author Louis Wasserman
35  */
36 public class DoubleMathRoundingBenchmark {
37   private static final double[] doubleInIntRange = new double[ARRAY_SIZE];
38   private static final double[] doubleInLongRange = new double[ARRAY_SIZE];
39   private static final double[] positiveDoubles = new double[ARRAY_SIZE];
40 
41   @Param({"DOWN", "UP", "FLOOR", "CEILING", "HALF_EVEN", "HALF_UP", "HALF_DOWN"})
42   RoundingMode mode;
43 
44   @BeforeExperiment
setUp()45   void setUp() {
46     for (int i = 0; i < ARRAY_SIZE; i++) {
47       doubleInIntRange[i] = randomDouble(Integer.SIZE - 2);
48       doubleInLongRange[i] = randomDouble(Long.SIZE - 2);
49       positiveDoubles[i] = randomPositiveDouble();
50     }
51   }
52 
roundToInt(int reps)53   @Benchmark int roundToInt(int reps) {
54     int tmp = 0;
55     for (int i = 0; i < reps; i++) {
56       int j = i & ARRAY_MASK;
57       tmp += DoubleMath.roundToInt(doubleInIntRange[j], mode);
58     }
59     return tmp;
60   }
61 
roundToLong(int reps)62   @Benchmark long roundToLong(int reps) {
63     long tmp = 0;
64     for (int i = 0; i < reps; i++) {
65       int j = i & ARRAY_MASK;
66       tmp += DoubleMath.roundToLong(doubleInLongRange[j], mode);
67     }
68     return tmp;
69   }
70 
roundToBigInteger(int reps)71   @Benchmark int roundToBigInteger(int reps) {
72     int tmp = 0;
73     for (int i = 0; i < reps; i++) {
74       int j = i & ARRAY_MASK;
75       tmp += DoubleMath.roundToBigInteger(positiveDoubles[j], mode).intValue();
76     }
77     return tmp;
78   }
79 
log2Round(int reps)80   @Benchmark int log2Round(int reps) {
81     int tmp = 0;
82     for (int i = 0; i < reps; i++) {
83       int j = i & ARRAY_MASK;
84       tmp += DoubleMath.log2(positiveDoubles[j], mode);
85     }
86     return tmp;
87   }
88 }
89