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      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
     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 
     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 
     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 
     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 
     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