ceph/src/boost/libs/math/reporting/performance/performance.hpp

   1 //  Copyright John Maddock 2015.
   2 //  Use, modification and distribution are subject to the
   3 //  Boost Software License, Version 1.0. (See accompanying file
   4 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   5
   6 #ifndef PERFORMANCE_HPP
   7 #define PERFORMANCE_HPP
   8
   9 #include <boost/math/special_functions/relative_difference.hpp>
  10 #include <boost/array.hpp>
  11 #include <boost/chrono.hpp>
  12 #include <boost/regex.hpp>
  13
  14 template <class Array>
  15 void add_data(const Array& a)
  16 {
  17    //
  18    // This function is called multiple times to merge multiple data sets into one big table:
  19    //
  20    for(typename Array::const_iterator i = a.begin(); i != a.end(); ++i)
  21    {
  22       data.push_back(std::vector<double>());
  23       for(typename Array::value_type::const_iterator j = i->begin(); j != i->end(); ++j)
  24       {
  25          data.back().push_back(*j);
  26       }
  27    }
  28 }
  29
  30 template <class Func, class Result>
  31 void screen_data(Func f, Result r)
  32 {
  33    //
  34    // If any of the implementations being tested produces garbage for one of our
  35    // test cases (or else if we test a domain they don't support), then we remove that
  36    // row from the table.  This allows us to only test a common supported sub-set for performance:
  37    //
  38    for(std::vector<std::vector<double> >::size_type row = 0; row < data.size(); ++row)
  39    {
  40       try
  41       {
  42          double computed = f(data[row]);
  43          double expected = r(data[row]);
  44          double err = boost::math::relative_difference(computed, expected);
  45          if(err > 1e-7)
  46          {
  47             std::cout << "Erasing row: ";
  48             for(unsigned i = 0; i < data[row].size(); ++i)
  49             {
  50                std::cout << data[row][i] << " ";
  51             }
  52             std::cout << "Error was " << err << std::endl;
  53             data.erase(data.begin() + row);
  54             --row;
  55          }
  56       }
  57       catch(const std::exception& e)
  58       {
  59          std::cout << "Erasing row: ";
  60          for(unsigned i = 0; i < data[row].size(); ++i)
  61          {
  62             std::cout << data[row][i] << " ";
  63          }
  64          std::cout << "due to thrown exception: " << e.what() << std::endl;
  65          data.erase(data.begin() + row);
  66          --row;
  67       }
  68    }
  69 }
  70
  71 template <class Clock>
  72 struct stopwatch
  73 {
  74    typedef typename Clock::duration duration;
  75    stopwatch()
  76    {
  77       m_start = Clock::now();
  78    }
  79    duration elapsed()
  80    {
  81       return Clock::now() - m_start;
  82    }
  83    void reset()
  84    {
  85       m_start = Clock::now();
  86    }
  87
  88 private:
  89    typename Clock::time_point m_start;
  90 };
  91
  92 double sum = 0;
  93
  94 template <class Func>
  95 double exec_timed_test(Func f)
  96 {
  97    double t = 0;
  98    unsigned repeats = 1;
  99    do{
 100       stopwatch<boost::chrono::high_resolution_clock> w;
 101
 102       for(unsigned count = 0; count < repeats; ++count)
 103       {
 104          for(std::vector<std::vector<double> >::const_iterator i = data.begin(); i != data.end(); ++i)
 105             sum += f(*i);
 106       }
 107
 108       t = boost::chrono::duration_cast<boost::chrono::duration<double>>(w.elapsed()).count();
 109       if(t < 0.5)
 110          repeats *= 2;
 111    } while(t < 0.5);
 112    return t / (repeats * data.size());
 113 }
 114
 115 #endif // PERFORMANCE_HPP