1 /*

     2  * Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  */

    23 

    24 /**

    25  * @test

    26  * @bug 7177917

    27  * @summary Micro-benchmark for Math.pow() and Math.exp()

    28  * @modules java.base/jdk.internal.misc

    29  * @library /test/lib

    30  *

    31  * @run main compiler.c2.Test7177917

    32  */

    33 

    34 package compiler.c2;

    35 

    36 import jdk.test.lib.Utils;

    37 

    38 import java.util.Random;

    39 

    40 public class Test7177917 {

    41 

    42   static double d;

    43 

    44   static final Random R = Utils.getRandomInstance();

    45 

    46   static long  m_pow(double[][] values) {

    47     double res = 0;

    48     long start = System.nanoTime();

    49     for (int i = 0; i < values.length; i++) {

    50       res += Math.pow(values[i][0], values[i][1]);

    51     }

    52     long stop = System.nanoTime();

    53     d = res;

    54     return (stop - start) / 1000;

    55   }

    56 

    57   static long  m_exp(double[] values) {

    58     double res = 0;

    59     long start = System.nanoTime();

    60     for (int i = 0; i < values.length; i++) {

    61       res += Math.exp(values[i]);

    62     }

    63     long stop = System.nanoTime();

    64     d = res;

    65     return (stop - start) / 1000;

    66   }

    67 

    68   static double[][] pow_values(int nb) {

    69     double[][] res = new double[nb][2];

    70     for (int i = 0; i < nb; i++) {

    71       double ylogx = (1 + (R.nextDouble() * 2045)) - 1023; // 2045 rather than 2046 as a safety margin

    72       double x = Math.abs(Double.longBitsToDouble(R.nextLong()));

    73       while (x != x) {

    74         x = Math.abs(Double.longBitsToDouble(R.nextLong()));

    75       }

    76       double logx = Math.log(x) / Math.log(2);

    77       double y = ylogx / logx;

    78 

    79       res[i][0] = x;

    80       res[i][1] = y;

    81     }

    82     return res;

    83   }

    84 

    85   static double[] exp_values(int nb) {

    86     double[] res = new double[nb];

    87     for (int i = 0; i < nb; i++) {

    88       double ylogx = (1 + (R.nextDouble() * 2045)) - 1023; // 2045 rather than 2046 as a safety margin

    89       double x = Math.E;

    90       double logx = Math.log(x) / Math.log(2);

    91       double y = ylogx / logx;

    92       res[i] = y;

    93     }

    94     return res;

    95   }

    96 

    97   static public void main(String[] args) {

    98     {

    99       // warmup

   100       double[][] warmup_values = pow_values(10);

   101       m_pow(warmup_values);

   102 

   103       for (int i = 0; i < 20000; i++) {

   104         m_pow(warmup_values);

   105       }

   106       // test pow perf

   107       double[][] values = pow_values(1000000);

   108       System.out.println("==> POW " + m_pow(values));

   109 

   110       // force uncommon trap

   111       double[][] nan_values = new double[1][2];

   112       nan_values[0][0] = Double.NaN;

   113       nan_values[0][1] = Double.NaN;

   114       m_pow(nan_values);

   115 

   116       // force recompilation

   117       for (int i = 0; i < 20000; i++) {

   118         m_pow(warmup_values);

   119       }

   120 

   121       // test pow perf again

   122       System.out.println("==> POW " + m_pow(values));

   123     }

   124     {

   125       // warmup

   126       double[] warmup_values = exp_values(10);

   127       m_exp(warmup_values);

   128 

   129       for (int i = 0; i < 20000; i++) {

   130         m_exp(warmup_values);

   131       }

   132 

   133       // test pow perf

   134       double[] values = exp_values(1000000);

   135       System.out.println("==> EXP " + m_exp(values));

   136 

   137       // force uncommon trap

   138       double[] nan_values = new double[1];

   139       nan_values[0] = Double.NaN;

   140       m_exp(nan_values);

   141 

   142       // force recompilation

   143       for (int i = 0; i < 20000; i++) {

   144         m_exp(warmup_values);

   145       }

   146 

   147       // test pow perf again

   148       System.out.println("==> EXP " + m_exp(values));

   149     }

   150   }

   151 }