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.randomNonZeroBigInteger;
22  import static com.google.common.math.MathBenchmarking.randomPositiveBigInteger;
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.BigIntegerMath;
28  
29  import java.math.BigInteger;
30  import java.math.RoundingMode;
31  
32  /**
33   * Benchmarks for the rounding methods of {@code BigIntegerMath}.
34   * 
35   * @author Louis Wasserman
36   */
37  public class BigIntegerMathRoundingBenchmark {
38    private static final BigInteger[] nonzero1 = new BigInteger[ARRAY_SIZE];
39    private static final BigInteger[] nonzero2 = new BigInteger[ARRAY_SIZE];
40    private static final BigInteger[] positive = new BigInteger[ARRAY_SIZE];
41  
42    @Param({"DOWN", "UP", "FLOOR", "CEILING", "HALF_EVEN", "HALF_UP", "HALF_DOWN"})
43    RoundingMode mode;
44  
45    @BeforeExperiment
46    void setUp() {
47      for (int i = 0; i < ARRAY_SIZE; i++) {
48        positive[i] = randomPositiveBigInteger(1024);
49        nonzero1[i] = randomNonZeroBigInteger(1024);
50        nonzero2[i] = randomNonZeroBigInteger(1024);
51      }
52    }
53  
54    @Benchmark int log2(int reps) {
55      int tmp = 0;
56      for (int i = 0; i < reps; i++) {
57        int j = i & ARRAY_MASK;
58        tmp += BigIntegerMath.log2(positive[j], mode);
59      }
60      return tmp;
61    }
62  
63    @Benchmark int log10(int reps) {
64      int tmp = 0;
65      for (int i = 0; i < reps; i++) {
66        int j = i & ARRAY_MASK;
67        tmp += BigIntegerMath.log10(positive[j], mode);
68      }
69      return tmp;
70    }
71  
72    @Benchmark int sqrt(int reps) {
73      int tmp = 0;
74      for (int i = 0; i < reps; i++) {
75        int j = i & ARRAY_MASK;
76        tmp += BigIntegerMath.sqrt(positive[j], mode).intValue();
77      }
78      return tmp;
79    }
80  
81    @Benchmark int divide(int reps) {
82      int tmp = 0;
83      for (int i = 0; i < reps; i++) {
84        int j = i & ARRAY_MASK;
85        tmp += BigIntegerMath.divide(nonzero1[j], nonzero2[j], mode).intValue();
86      }
87      return tmp;
88    }
89  }