/*

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

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

 *

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

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

 * published by the Free Software Foundation.

 *

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

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

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

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

 * accompanied this code).

 *

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

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

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

 *

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

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

 * questions.

 *

 */

/*

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

 */

import java.util.*;

public class Test7177917 {

  static double d;

  static Random r = new Random(0);

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

    double res = 0;

    long start = System.nanoTime();

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

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

    }

    long stop = System.nanoTime();

    d = res;

    return (stop - start) / 1000;

  }

  static long  m_exp(double[] values) {

    double res = 0;

    long start = System.nanoTime();

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

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

    }

    long stop = System.nanoTime();

    d = res;

    return (stop - start) / 1000;

  }

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

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

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

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

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

      while (x != x) {

        x = Math.abs(Double.longBitsToDouble(r.nextLong()));

      }

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

      double y = ylogx / logx;

      res[i][0] = x;

      res[i][1] = y;

    }

    return res;

  }

  static double[] exp_values(int nb) {

    double[] res = new double[nb];

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

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

      double x = Math.E;

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

      double y = ylogx / logx;

      res[i] = y;

    }

    return res;

  }

  static public void main(String[] args) {

    {

      // warmup

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

      m_pow(warmup_values);

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

        m_pow(warmup_values);

      }

      // test pow perf

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

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

      // force uncommon trap

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

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

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

      m_pow(nan_values);

      // force recompilation

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

        m_pow(warmup_values);

      }

      // test pow perf again

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

    }

    {

      // warmup

      double[] warmup_values = exp_values(10);

      m_exp(warmup_values);

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

        m_exp(warmup_values);

      }

      // test pow perf

      double[] values = exp_values(1000000);

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

      // force uncommon trap

      double[] nan_values = new double[1];

      nan_values[0] = Double.NaN;

      m_exp(nan_values);

      // force recompilation

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

        m_exp(warmup_values);

      }

      // test pow perf again

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

    }

  }

}