spirit/workbench/qi/real_parser.cpp
2014-04-01 15:06:38 +08:00

119 lines
3.5 KiB
C++

/*=============================================================================
Copyright (c) 2001-2010 Joel de Guzman
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
==============================================================================*/
#include "../measure.hpp"
#include <string>
#include <vector>
#include <cstdlib>
#include <boost/spirit/include/qi.hpp>
namespace
{
int const ndigits = 9;
std::string numbers[ndigits] =
{
"1234",
"-1.2e3",
"0.1",
"-1.2e-3",
"-.2e3",
"-2e6",
"1.2345e5",
"-5.7222349715140557e+307",
"2.0332938517515416e-308"
};
char const* first[ndigits];
char const* last[ndigits];
///////////////////////////////////////////////////////////////////////////
struct atof_test : test::base
{
void benchmark()
{
for (int i = 0; i < ndigits; ++i)
{
double d = atof(first[i]);
this->val += *reinterpret_cast<int*>(&d);
}
}
};
///////////////////////////////////////////////////////////////////////////
struct strtod_test : test::base
{
void benchmark()
{
for (int i = 0; i < ndigits; ++i)
{
double d = strtod(first[i], const_cast<char**>(&last[i]));
this->val += *reinterpret_cast<int*>(&d);
}
}
};
///////////////////////////////////////////////////////////////////////////
struct spirit_double_test : test::base
{
static double parse(char const* first, char const* last)
{
double n;
namespace qi = boost::spirit::qi;
using qi::double_;
qi::parse(first, last, double_, n);
return n;
}
void benchmark()
{
for (int i = 0; i < ndigits; ++i)
{
double d = parse(first[i], last[i]);
this->val += *reinterpret_cast<int*>(&d);
}
}
};
}
int main()
{
std::cout << "///////////////////////////////////////////////////////////////////////////" << std::endl;
std::cout << "Numbers to test:" << std::endl;
for (int i = 0; i < ndigits; ++i)
{
first[i] = numbers[i].c_str();
last[i] = first[i];
while (*last[i])
last[i]++;
std::cout << numbers[i] << std::endl;
}
std::cout.precision(17);
std::cout << "///////////////////////////////////////////////////////////////////////////" << std::endl;
std::cout << "atof/strtod/qi.double results:" << std::endl;
for (int i = 0; i < ndigits; ++i)
{
std::cout
<< atof(first[i]) << ','
<< strtod(first[i], const_cast<char**>(&last[i])) << ','
<< spirit_double_test::parse(first[i], last[i]) << ','
<< std::endl;
}
std::cout << "///////////////////////////////////////////////////////////////////////////" << std::endl;
BOOST_SPIRIT_TEST_BENCHMARK(
10000000, // This is the maximum repetitions to execute
(atof_test)
(strtod_test)
(spirit_double_test)
)
// This is ultimately responsible for preventing all the test code
// from being optimized away. Change this to return 0 and you
// unplug the whole test's life support system.
return test::live_code != 0;
}