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1 /* |
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2 * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. |
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8 * |
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9 * This code is distributed in the hope that it will be useful, but WITHOUT |
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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12 * version 2 for more details (a copy is included in the LICENSE file that |
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13 * accompanied this code). |
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14 * |
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15 * You should have received a copy of the GNU General Public License version |
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16 * 2 along with this work; if not, write to the Free Software Foundation, |
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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18 * |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
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22 * |
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23 */ |
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24 |
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25 /* |
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26 * Micro-benchmark for Math.pow() and Math.exp() |
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27 */ |
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28 |
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29 import java.util.*; |
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30 |
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31 public class Test7177917 { |
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32 |
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33 static double d; |
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34 |
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35 static Random r = new Random(0); |
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36 |
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37 static long m_pow(double[][] values) { |
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38 double res = 0; |
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39 long start = System.nanoTime(); |
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40 for (int i = 0; i < values.length; i++) { |
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41 res += Math.pow(values[i][0], values[i][1]); |
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42 } |
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43 long stop = System.nanoTime(); |
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44 d = res; |
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45 return (stop - start) / 1000; |
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46 } |
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47 |
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48 static long m_exp(double[] values) { |
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49 double res = 0; |
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50 long start = System.nanoTime(); |
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51 for (int i = 0; i < values.length; i++) { |
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52 res += Math.exp(values[i]); |
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53 } |
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54 long stop = System.nanoTime(); |
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55 d = res; |
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56 return (stop - start) / 1000; |
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57 } |
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58 |
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59 static double[][] pow_values(int nb) { |
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60 double[][] res = new double[nb][2]; |
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61 for (int i = 0; i < nb; i++) { |
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62 double ylogx = (1 + (r.nextDouble() * 2045)) - 1023; // 2045 rather than 2046 as a safety margin |
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63 double x = Math.abs(Double.longBitsToDouble(r.nextLong())); |
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64 while (x != x) { |
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65 x = Math.abs(Double.longBitsToDouble(r.nextLong())); |
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66 } |
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67 double logx = Math.log(x) / Math.log(2); |
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68 double y = ylogx / logx; |
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69 |
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70 res[i][0] = x; |
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71 res[i][1] = y; |
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72 } |
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73 return res; |
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74 } |
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75 |
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76 static double[] exp_values(int nb) { |
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77 double[] res = new double[nb]; |
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78 for (int i = 0; i < nb; i++) { |
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79 double ylogx = (1 + (r.nextDouble() * 2045)) - 1023; // 2045 rather than 2046 as a safety margin |
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80 double x = Math.E; |
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81 double logx = Math.log(x) / Math.log(2); |
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82 double y = ylogx / logx; |
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83 res[i] = y; |
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84 } |
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85 return res; |
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86 } |
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87 |
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88 static public void main(String[] args) { |
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89 { |
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90 // warmup |
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91 double[][] warmup_values = pow_values(10); |
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92 m_pow(warmup_values); |
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93 |
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94 for (int i = 0; i < 20000; i++) { |
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95 m_pow(warmup_values); |
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96 } |
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97 // test pow perf |
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98 double[][] values = pow_values(1000000); |
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99 System.out.println("==> POW " + m_pow(values)); |
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100 |
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101 // force uncommon trap |
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102 double[][] nan_values = new double[1][2]; |
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103 nan_values[0][0] = Double.NaN; |
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104 nan_values[0][1] = Double.NaN; |
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105 m_pow(nan_values); |
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106 |
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107 // force recompilation |
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108 for (int i = 0; i < 20000; i++) { |
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109 m_pow(warmup_values); |
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110 } |
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111 |
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112 // test pow perf again |
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113 System.out.println("==> POW " + m_pow(values)); |
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114 } |
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115 { |
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116 // warmup |
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117 double[] warmup_values = exp_values(10); |
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118 m_exp(warmup_values); |
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119 |
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120 for (int i = 0; i < 20000; i++) { |
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121 m_exp(warmup_values); |
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122 } |
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123 |
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124 // test pow perf |
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125 double[] values = exp_values(1000000); |
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126 System.out.println("==> EXP " + m_exp(values)); |
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127 |
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128 // force uncommon trap |
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129 double[] nan_values = new double[1]; |
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130 nan_values[0] = Double.NaN; |
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131 m_exp(nan_values); |
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132 |
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133 // force recompilation |
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134 for (int i = 0; i < 20000; i++) { |
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135 m_exp(warmup_values); |
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136 } |
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137 |
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138 // test pow perf again |
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139 System.out.println("==> EXP " + m_exp(values)); |
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140 } |
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141 } |
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142 } |