Files
charconv/benchmark/from_chars_floating.cpp
2023-08-02 11:20:27 -04:00

282 lines
7.9 KiB
C++

// Copyright 2023 Peter Dimov
// Copyright 2023 Matt Borland
// Distributed under the Boost Software License, Version 1.0.
// https://www.boost.org/LICENSE_1_0.txt
#include <boost/charconv/from_chars.hpp>
#include <boost/charconv/to_chars.hpp>
#include <boost/core/type_name.hpp>
#include <boost/core/detail/splitmix64.hpp>
#include <boost/config.hpp>
#include <type_traits>
#include <chrono>
#include <cstdio>
#include <iostream>
#include <iomanip>
#include <charconv>
#include <random>
constexpr unsigned N = 2'000'000;
constexpr int K = 10;
template<class T> static BOOST_NOINLINE void init_input_data( std::vector<std::string>& data, bool general )
{
data.reserve( N );
boost::detail::splitmix64 rng;
for( unsigned i = 0; i < N; ++i )
{
std::uint64_t tmp = rng();
T x;
std::memcpy( &x, &tmp, sizeof(x) );
if( !std::isfinite(x) ) continue;
char buffer[ 64 ];
auto r = boost::charconv::to_chars( buffer, buffer + sizeof( buffer ), x, general? boost::charconv::chars_format::general: boost::charconv::chars_format::scientific );
std::string y( buffer, r.ptr );
data.push_back( y );
}
}
template <>
BOOST_NOINLINE void init_input_data<long double>( std::vector<std::string>& data, bool general )
{
data.reserve(N / 10);
std::random_device rd;
std::mt19937_64 rng(rd());
std::uniform_real_distribution<long double> dist(0.0L, (std::numeric_limits<long double>::max)());
for( unsigned i = 0; i < N / 10; ++i )
{
const long double x = dist(rng);
char buffer[ 64 ];
auto r = boost::charconv::to_chars( buffer, buffer + sizeof( buffer ), x, general? boost::charconv::chars_format::general : boost::charconv::chars_format::scientific );
std::string y( buffer, r.ptr );
data.push_back( y );
}
}
template<class T> static BOOST_NOINLINE void init_input_data_uint64( std::vector<std::string>& data )
{
data.reserve( N );
boost::detail::splitmix64 rng;
for( unsigned i = 0; i < N; ++i )
{
std::uint64_t x = rng();
char buffer[ 64 ];
auto r = boost::charconv::to_chars( buffer, buffer + sizeof( buffer ), x );
std::string y( buffer, r.ptr );
data.push_back( y );
}
}
using namespace std::chrono_literals;
template<class T> void test_strtox( std::vector<std::string> const& data, bool general, char const* label );
template<> BOOST_NOINLINE void test_strtox<float>( std::vector<std::string> const& data, bool, char const* label )
{
auto t1 = std::chrono::steady_clock::now();
double s = 0;
for( int i = 0; i < K; ++i )
{
for( auto const& x: data )
{
float y = std::strtof( x.c_str(), nullptr );
s = s / 16.0 + y;
}
}
auto t2 = std::chrono::steady_clock::now();
std::cout << " std::strtox<float>, " << label << ": " << std::setw( 5 ) << ( t2 - t1 ) / 1ms << " ms (s=" << s << ")\n";
}
template<> BOOST_NOINLINE void test_strtox<double>( std::vector<std::string> const& data, bool, char const* label )
{
auto t1 = std::chrono::steady_clock::now();
double s = 0;
for( int i = 0; i < K; ++i )
{
for( auto const& x: data )
{
double y = std::strtod( x.c_str(), nullptr );
s = s / 16.0 + y;
}
}
auto t2 = std::chrono::steady_clock::now();
std::cout << " std::strtox<double>, " << label << ": " << std::setw( 5 ) << ( t2 - t1 ) / 1ms << " ms (s=" << s << ")\n";
}
template<> BOOST_NOINLINE void test_strtox<long double>( std::vector<std::string> const& data, bool, char const* label )
{
auto t1 = std::chrono::steady_clock::now();
long double s = 0;
for( int i = 0; i < K; ++i )
{
for( auto const& x: data )
{
double y = std::strtold( x.c_str(), nullptr );
s = s / 16.0L + y;
}
}
auto t2 = std::chrono::steady_clock::now();
std::cout << " std::strtox<long double>, " << label << ": " << std::setw( 5 ) << ( t2 - t1 ) / 1ms << " ms (s=" << s << ")\n";
}
template<class T> static BOOST_NOINLINE void test_std_from_chars( std::vector<std::string> const& data, bool general, char const* label )
{
auto t1 = std::chrono::steady_clock::now();
double s = 0;
for( int i = 0; i < K; ++i )
{
for( auto const& x: data )
{
T y;
std::from_chars( x.data(), x.data() + x.size(), y, general? std::chars_format::general: std::chars_format::scientific );
s = s / 16.0 + y;
}
}
auto t2 = std::chrono::steady_clock::now();
std::cout << " std::from_chars<" << boost::core::type_name<T>() << ">, " << label << ": " << std::setw( 5 ) << ( t2 - t1 ) / 1ms << " ms (s=" << s << ")\n";
}
template<> BOOST_NOINLINE void test_std_from_chars<long double>( std::vector<std::string> const& data, bool general, char const* label )
{
auto t1 = std::chrono::steady_clock::now();
long double s = 0;
for( int i = 0; i < K; ++i )
{
for( auto const& x: data )
{
long double y;
std::from_chars( x.data(), x.data() + x.size(), y, general? std::chars_format::general: std::chars_format::scientific );
s = s / 16.0L + y;
}
}
auto t2 = std::chrono::steady_clock::now();
std::cout << " std::from_chars<long double>, " << label << ": " << std::setw( 5 ) << ( t2 - t1 ) / 1ms << " ms (s=" << s << ")\n";
}
template<class T> static BOOST_NOINLINE void test_boost_from_chars( std::vector<std::string> const& data, bool general, char const* label )
{
auto t1 = std::chrono::steady_clock::now();
double s = 0;
for( int i = 0; i < K; ++i )
{
for( auto const& x: data )
{
T y;
boost::charconv::from_chars( x.data(), x.data() + x.size(), y, general? boost::charconv::chars_format::general: boost::charconv::chars_format::scientific );
s = s / 16.0 + y;
}
}
auto t2 = std::chrono::steady_clock::now();
std::cout << "boost::charconv::from_chars<" << boost::core::type_name<T>() << ">, " << label << ": " << std::setw( 5 ) << ( t2 - t1 ) / 1ms << " ms (s=" << s << ")\n";
}
template<>
BOOST_NOINLINE void test_boost_from_chars<long double>( std::vector<std::string> const& data, bool general, char const* label )
{
auto t1 = std::chrono::steady_clock::now();
long double s = 0;
for( int i = 0; i < K; ++i )
{
for( auto const& x: data )
{
long double y;
boost::charconv::from_chars( x.data(), x.data() + x.size(), y, general? boost::charconv::chars_format::general: boost::charconv::chars_format::scientific );
s = s / 16.0L + y;
}
}
auto t2 = std::chrono::steady_clock::now();
std::cout << "boost::charconv::from_chars<long double>, " << label << ": " << std::setw( 5 ) << ( t2 - t1 ) / 1ms << " ms (s=" << s << ")\n";
}
template<class T> static void test( bool general )
{
std::vector<std::string> data;
init_input_data<T>( data, general );
char const* label = general? "general": "scientific";
test_strtox<T>( data, general, label );
test_std_from_chars<T>( data, general, label );
test_boost_from_chars<T>( data, general, label );
std::cout << std::endl;
}
template<class T> static void test2()
{
std::vector<std::string> data;
init_input_data_uint64<T>( data );
bool general = true;
char const* label = "uint64";
test_strtox<T>( data, general, label );
test_std_from_chars<T>( data, general, label );
test_boost_from_chars<T>( data, general, label );
std::cout << std::endl;
}
int main()
{
std::cout << BOOST_COMPILER << "\n";
std::cout << BOOST_STDLIB << "\n\n";
test<float>( false );
test<double>( false );
test<long double>( false );
test<float>( true );
test<double>( true );
test<long double>( true );
test2<float>();
test2<double>();
}