math/reporting/performance/test_gcd.cpp
2017-11-09 19:39:32 +00:00

479 lines
14 KiB
C++

// Copyright Jeremy Murphy 2016.
// Use, modification and distribution are subject to 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)
#ifdef _MSC_VER
# pragma warning (disable : 4224)
#endif
#include <boost/math/common_factor_rt.hpp>
#include <boost/math/special_functions/prime.hpp>
#include <boost/multiprecision/cpp_int.hpp>
#include <boost/multiprecision/integer.hpp>
#include <boost/random.hpp>
#include <boost/array.hpp>
#include <iostream>
#include <algorithm>
#include <numeric>
#include <string>
#include <tuple>
#include <type_traits>
#include <vector>
#include <functional>
#include "fibonacci.hpp"
#include "../../test/table_type.hpp"
#include "table_helper.hpp"
#include "performance.hpp"
using namespace std;
boost::multiprecision::cpp_int total_sum(0);
template <typename Func, class Table>
double exec_timed_test_foo(Func f, const Table& data, double min_elapsed = 0.5)
{
double t = 0;
unsigned repeats = 1;
typename Table::value_type::first_type sum{0};
stopwatch<boost::chrono::high_resolution_clock> w;
do
{
for(unsigned count = 0; count < repeats; ++count)
{
for(typename Table::size_type n = 0; n < data.size(); ++n)
sum += f(data[n].first, data[n].second);
}
t = boost::chrono::duration_cast<boost::chrono::duration<double>>(w.elapsed()).count();
if(t < min_elapsed)
repeats *= 2;
}
while(t < min_elapsed);
total_sum += sum;
return t / repeats;
}
template <typename T>
struct test_function_template
{
vector<pair<T, T> > const & data;
const char* data_name;
test_function_template(vector<pair<T, T> > const &data, const char* name) : data(data), data_name(name) {}
template <typename Function>
void operator()(pair<Function, string> const &f) const
{
auto result = exec_timed_test_foo(f.first, data);
auto table_name = string("gcd method comparison with ") + compiler_name() + string(" on ") + platform_name();
report_execution_time(result,
table_name,
string(data_name),
string(f.second) + "\n" + boost_name());
}
};
boost::random::mt19937 rng;
boost::random::uniform_int_distribution<> d_0_6(0, 6);
boost::random::uniform_int_distribution<> d_1_20(1, 20);
template <class T>
T get_prime_products()
{
int n_primes = d_0_6(rng);
switch(n_primes)
{
case 0:
// Generate a power of 2:
return static_cast<T>(1u) << d_1_20(rng);
case 1:
// prime number:
return boost::math::prime(d_1_20(rng) + 3);
}
T result = 1;
for(int i = 0; i < n_primes; ++i)
result *= boost::math::prime(d_1_20(rng) + 3) * boost::math::prime(d_1_20(rng) + 3) * boost::math::prime(d_1_20(rng) + 3) * boost::math::prime(d_1_20(rng) + 3) * boost::math::prime(d_1_20(rng) + 3);
return result;
}
template <class T>
T get_uniform_random()
{
static boost::random::uniform_int_distribution<T> minmax((std::numeric_limits<T>::min)(), (std::numeric_limits<T>::max)());
return minmax(rng);
}
template <class T>
inline bool even(T const& val)
{
return !(val & 1u);
}
template <class Backend, boost::multiprecision::expression_template_option ExpressionTemplates>
inline bool even(boost::multiprecision::number<Backend, ExpressionTemplates> const& val)
{
return !bit_test(val, 0);
}
template <class T>
T euclid_textbook(T a, T b)
{
using std::swap;
if(a < b)
swap(a, b);
while(b)
{
T t = b;
b = a % b;
a = t;
}
return a;
}
template <class T>
T binary_textbook(T u, T v)
{
if(u && v)
{
unsigned shifts = (std::min)(boost::multiprecision::lsb(u), boost::multiprecision::lsb(v));
if(shifts)
{
u >>= shifts;
v >>= shifts;
}
while(u)
{
unsigned bit_index = boost::multiprecision::lsb(u);
if(bit_index)
{
u >>= bit_index;
}
else if(bit_index = boost::multiprecision::lsb(v))
{
v >>= bit_index;
}
else
{
if(u < v)
v = (v - u) >> 1u;
else
u = (u - v) >> 1u;
}
}
return v << shifts;
}
return u + v;
}
template <typename Integer>
inline BOOST_CXX14_CONSTEXPR Integer gcd_default(Integer a, Integer b) BOOST_GCD_NOEXCEPT(Integer)
{
using boost::math::gcd;
return gcd(a, b);
}
template <class T>
void test_type(const char* name)
{
using namespace boost::math::gcd_detail;
typedef T int_type;
std::vector<pair<int_type, int_type> > data;
for(unsigned i = 0; i < 1000; ++i)
{
data.push_back(std::make_pair(get_prime_products<T>(), get_prime_products<T>()));
}
std::string row_name("gcd<");
row_name += name;
row_name += "> (random prime number products)";
typedef pair< function<int_type(int_type, int_type)>, string> f_test;
array<f_test, 6> test_functions{ {
{ gcd_default<int_type>, "gcd" },
{ Euclid_gcd<int_type>, "Euclid_gcd" },
{ Stein_gcd<int_type>, "Stein_gcd" } ,
{ mixed_binary_gcd<int_type>, "mixed_binary_gcd" },
{ binary_textbook<int_type>, "Stein_gcd_textbook" },
{ euclid_textbook<int_type>, "gcd_euclid_textbook" },
} };
for_each(begin(test_functions), end(test_functions), test_function_template<int_type>(data, row_name.c_str()));
data.clear();
for(unsigned i = 0; i < 1000; ++i)
{
data.push_back(std::make_pair(get_uniform_random<T>(), get_uniform_random<T>()));
}
row_name.erase();
row_name += "gcd<";
row_name += name;
row_name += "> (uniform random numbers)";
for_each(begin(test_functions), end(test_functions), test_function_template<int_type>(data, row_name.c_str()));
// Fibonacci number tests:
row_name.erase();
row_name += "gcd<";
row_name += name;
row_name += "> (adjacent Fibonacci numbers)";
for_each(begin(test_functions), end(test_functions), test_function_template<int_type>(fibonacci_numbers_permution_1<T>(), row_name.c_str()));
row_name.erase();
row_name += "gcd<";
row_name += name;
row_name += "> (permutations of Fibonacci numbers)";
for_each(begin(test_functions), end(test_functions), test_function_template<int_type>(fibonacci_numbers_permution_2<T>(), row_name.c_str()));
row_name.erase();
row_name += "gcd<";
row_name += name;
row_name += "> (Trivial cases)";
for_each(begin(test_functions), end(test_functions), test_function_template<int_type>(trivial_gcd_test_cases<T>(), row_name.c_str()));
}
/*******************************************************************************************************************/
template <class T>
T generate_random(unsigned bits_wanted)
{
static boost::random::mt19937 gen;
typedef boost::random::mt19937::result_type random_type;
T max_val;
unsigned digits;
if(std::numeric_limits<T>::is_bounded && (bits_wanted == (unsigned)std::numeric_limits<T>::digits))
{
max_val = (std::numeric_limits<T>::max)();
digits = std::numeric_limits<T>::digits;
}
else
{
max_val = T(1) << bits_wanted;
digits = bits_wanted;
}
unsigned bits_per_r_val = std::numeric_limits<random_type>::digits - 1;
while((random_type(1) << bits_per_r_val) > (gen.max)()) --bits_per_r_val;
unsigned terms_needed = digits / bits_per_r_val + 1;
T val = 0;
for(unsigned i = 0; i < terms_needed; ++i)
{
val *= (gen.max)();
val += gen();
}
val %= max_val;
return val;
}
template <typename N>
N gcd_stein(N m, N n)
{
BOOST_ASSERT(m >= static_cast<N>(0));
BOOST_ASSERT(n >= static_cast<N>(0));
if(m == N(0)) return n;
if(n == N(0)) return m;
// m > 0 && n > 0
unsigned d_m = 0;
while(even(m)) { m >>= 1; d_m++; }
unsigned d_n = 0;
while(even(n)) { n >>= 1; d_n++; }
// odd(m) && odd(n)
while(m != n) {
if(n > m) swap(n, m);
m -= n;
do m >>= 1; while(even(m));
// m == n
}
return m << (std::min)(d_m, d_n);
}
boost::multiprecision::cpp_int big_gcd(const boost::multiprecision::cpp_int& a, const boost::multiprecision::cpp_int& b)
{
return boost::multiprecision::gcd(a, b);
}
namespace boost { namespace multiprecision { namespace backends {
template <unsigned MinBits1, unsigned MaxBits1, cpp_integer_type SignType1, cpp_int_check_type Checked1, class Allocator1>
inline typename enable_if_c<!is_trivial_cpp_int<cpp_int_backend<MinBits1, MaxBits1, SignType1, Checked1, Allocator1> >::value>::type
eval_gcd_new(
cpp_int_backend<MinBits1, MaxBits1, SignType1, Checked1, Allocator1>& result,
const cpp_int_backend<MinBits1, MaxBits1, SignType1, Checked1, Allocator1>& a,
const cpp_int_backend<MinBits1, MaxBits1, SignType1, Checked1, Allocator1>& b)
{
using default_ops::eval_lsb;
using default_ops::eval_is_zero;
using default_ops::eval_get_sign;
if(a.size() == 1)
{
eval_gcd(result, b, *a.limbs());
return;
}
if(b.size() == 1)
{
eval_gcd(result, a, *b.limbs());
return;
}
int shift;
cpp_int_backend<MinBits1, MaxBits1, SignType1, Checked1, Allocator1> u(a), v(b), mod;
int s = eval_get_sign(u);
/* GCD(0,x) := x */
if(s < 0)
{
u.negate();
}
else if(s == 0)
{
result = v;
return;
}
s = eval_get_sign(v);
if(s < 0)
{
v.negate();
}
else if(s == 0)
{
result = u;
return;
}
/* Let shift := lg K, where K is the greatest power of 2
dividing both u and v. */
unsigned us = eval_lsb(u);
unsigned vs = eval_lsb(v);
shift = (std::min)(us, vs);
eval_right_shift(u, us);
eval_right_shift(v, vs);
// From now on access u and v via pointers, that way we have a trivial swap:
cpp_int_backend<MinBits1, MaxBits1, SignType1, Checked1, Allocator1>* up(&u), *vp(&v), *mp(&mod);
do
{
/* Now u and v are both odd, so diff(u, v) is even.
Let u = min(u, v), v = diff(u, v)/2. */
s = up->compare(*vp);
if(s > 0)
std::swap(up, vp);
if(s == 0)
break;
if(vp->size() <= 2)
{
if(vp->size() == 1)
*up = boost::math::gcd_detail::mixed_binary_gcd(*vp->limbs(), *up->limbs());
else
{
double_limb_type i, j;
i = vp->limbs()[0] | (static_cast<double_limb_type>(vp->limbs()[1]) << sizeof(limb_type) * CHAR_BIT);
j = (up->size() == 1) ? *up->limbs() : up->limbs()[0] | (static_cast<double_limb_type>(up->limbs()[1]) << sizeof(limb_type) * CHAR_BIT);
u = boost::math::gcd_detail::mixed_binary_gcd(i, j);
}
break;
}
if(vp->size() > up->size() /*eval_msb(*vp) > eval_msb(*up) + 32*/)
{
eval_modulus(*mp, *vp, *up);
std::swap(vp, mp);
eval_subtract(*up, *vp);
if(eval_is_zero(*vp) == 0)
{
vs = eval_lsb(*vp);
eval_right_shift(*vp, vs);
}
else
break;
if(eval_is_zero(*up) == 0)
{
vs = eval_lsb(*up);
eval_right_shift(*up, vs);
}
else
{
std::swap(up, vp);
break;
}
}
else
{
eval_subtract(*vp, *up);
vs = eval_lsb(*vp);
eval_right_shift(*vp, vs);
}
}
while(true);
result = *up;
eval_left_shift(result, shift);
}
}}}
boost::multiprecision::cpp_int big_gcd_new(const boost::multiprecision::cpp_int& a, const boost::multiprecision::cpp_int& b)
{
boost::multiprecision::cpp_int result;
boost::multiprecision::backends::eval_gcd_new(result.backend(), a.backend(), b.backend());
return result;
}
#if 0
void test_n_bits(unsigned n, std::string data_name, const std::vector<pair<boost::multiprecision::cpp_int, boost::multiprecision::cpp_int> >* p_data = 0)
{
using namespace boost::math::detail;
typedef boost::multiprecision::cpp_int int_type;
std::vector<pair<int_type, int_type> > data, data2;
for(unsigned i = 0; i < 1000; ++i)
{
data.push_back(std::make_pair(generate_random<int_type>(n), generate_random<int_type>(n)));
}
typedef pair< function<int_type(int_type, int_type)>, string> f_test;
array<f_test, 2> test_functions{ { /*{ Stein_gcd<int_type>, "Stein_gcd" } ,{ Euclid_gcd<int_type>, "Euclid_gcd" },{ binary_textbook<int_type>, "Stein_gcd_textbook" },{ euclid_textbook<int_type>, "gcd_euclid_textbook" },{ mixed_binary_gcd<int_type>, "mixed_binary_gcd" },{ gcd_stein<int_type>, "gcd_stein" },*/{ big_gcd, "boost::multiprecision::gcd" },{ big_gcd_new, "big_gcd_new" } } };
for_each(begin(test_functions), end(test_functions), test_function_template<int_type>(p_data ? *p_data : data, data_name.c_str(), true));
}
#endif
int main()
{
test_type<unsigned short>("unsigned short");
test_type<unsigned>("unsigned");
test_type<unsigned long>("unsigned long");
test_type<unsigned long long>("unsigned long long");
test_type<boost::multiprecision::uint256_t>("boost::multiprecision::uint256_t");
test_type<boost::multiprecision::uint512_t>("boost::multiprecision::uint512_t");
test_type<boost::multiprecision::uint1024_t>("boost::multiprecision::uint1024_t");
/*
test_n_bits(16, " 16 bit random values");
test_n_bits(32, " 32 bit random values");
test_n_bits(64, " 64 bit random values");
test_n_bits(125, " 125 bit random values");
test_n_bits(250, " 250 bit random values");
test_n_bits(500, " 500 bit random values");
test_n_bits(1000, " 1000 bit random values");
test_n_bits(5000, " 5000 bit random values");
test_n_bits(10000, "10000 bit random values");
//test_n_bits(100000);
//test_n_bits(1000000);
test_n_bits(0, "consecutive first 1000 fibonacci numbers", &fibonacci_numbers_cpp_int_permution_1());
test_n_bits(0, "permutations of first 1000 fibonacci numbers", &fibonacci_numbers_cpp_int_permution_2());
*/
return 0;
}