text: // Copyright (c) 2017, The Argentum Project
  // 
  // All rights reserved.
  // 
  // Redistribution and use in source and binary forms, with or without modification, are
  // permitted provided that the following conditions are met:
  // 
  // 1. Redistributions of source code must retain the above copyright notice, this list of
  //    conditions and the following disclaimer.
  // 
  // 2. Redistributions in binary form must reproduce the above copyright notice, this list
  //    of conditions and the following disclaimer in the documentation and/or other
  //    materials provided with the distribution.
  // 
  // 3. Neither the name of the copyright holder nor the names of its contributors may be
  //    used to endorse or promote products derived from this software without specific
  //    prior written permission.
  // 
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
  // EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
  // THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  // STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
  // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  // 
  // Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
  
  #pragma once
  
  #include <iostream>
  #include <stdint.h>
  
  #include <boost/chrono.hpp>
  
  class performance_timer
  {
  public:
    typedef boost::chrono::high_resolution_clock clock;
  
    performance_timer()
    {
      m_base = clock::now();
    }
  
    void start()
    {
      m_start = clock::now();
    }
  
    int elapsed_ms()
    {
      clock::duration elapsed = clock::now() - m_start;
      return static_cast<int>(boost::chrono::duration_cast<boost::chrono::milliseconds>(elapsed).count());
    }
  
  private:
    clock::time_point m_base;
    clock::time_point m_start;
  };
  
  
  template <typename T>
  class test_runner
  {
  public:
    test_runner()
      : m_elapsed(0)
    {
    }
  
    bool run()
    {
      T test;
      if (!test.init())
        return false;
  
      performance_timer timer;
      timer.start();
      warm_up();
      std::cout << "Warm up: " << timer.elapsed_ms() << " ms" << std::endl;
  
      timer.start();
      for (size_t i = 0; i < T::loop_count; ++i)
      {
        if (!test.test())
          return false;
      }
      m_elapsed = timer.elapsed_ms();
  
      return true;
    }
  
    int elapsed_time() const { return m_elapsed; }
  
    int time_per_call(int scale = 1) const
    {
      static_assert(0 < T::loop_count, "T::loop_count must be greater than 0");
      return m_elapsed * scale / T::loop_count;
    }
  
  private:
    /**
     * Warm up processor core, enabling turbo boost, etc.
     */
    uint64_t warm_up()
    {
      const size_t warm_up_rounds = 1000 * 1000 * 1000;
      m_warm_up = 0;
      for (size_t i = 0; i < warm_up_rounds; ++i)
      {
        ++m_warm_up;
      }
      return m_warm_up;
    }
  
  private:
    volatile uint64_t m_warm_up;  ///<! This field is intended for preclude compiler optimizations
    int m_elapsed;
  };
  
  template <typename T>
  void run_test(const char* test_name)
  {
    test_runner<T> runner;
    if (runner.run())
    {
      std::cout << test_name << " - OK:\n";
      std::cout << "  loop count:    " << T::loop_count << '\n';
      std::cout << "  elapsed:       " << runner.elapsed_time() << " ms\n";
      const char *unit = "ms";
      int time_per_call = runner.time_per_call();
      if (time_per_call < 30000) {
       time_per_call = runner.time_per_call(1000);
  #ifdef _WIN32
       unit = "\xb5s";
  #else
       unit = "µs";
  #endif
      }
      std::cout << "  time per call: " << time_per_call << " " << unit << "/call\n" << std::endl;
    }
    else
    {
      std::cout << test_name << " - FAILED" << std::endl;
    }
  }
  
  #define QUOTEME(x) #x
  #define TEST_PERFORMANCE0(test_class)         run_test< test_class >(QUOTEME(test_class))
  #define TEST_PERFORMANCE1(test_class, a0)     run_test< test_class<a0> >(QUOTEME(test_class<a0>))
  #define TEST_PERFORMANCE2(test_class, a0, a1) run_test< test_class<a0, a1> >(QUOTEME(test_class) "<" QUOTEME(a0) ", " QUOTEME(a1) ">")
  #define TEST_PERFORMANCE3(test_class, a0, a1, a2) run_test< test_class<a0, a1, a2> >(QUOTEME(test_class) "<" QUOTEME(a0) ", " QUOTEME(a1) ", " QUOTEME(a2) ">")
  