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// Copyright 2020 John Maddock. Distributed under the Boost
// Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt
#include <iostream>
#include <benchmark/benchmark.h>
#include <boost/multiprecision/cpp_int.hpp>
#include <boost/multiprecision/gmp.hpp>
#include <gmpxx.h>
template <class Integer>
inline Integer factorial(unsigned n)
{
Integer result = 1;
for (unsigned k = 1; k <= n; ++k)
result *= k;
return result;
}
template <class Rational, class Integer = typename Rational::value_type>
inline Rational binomial(unsigned n, unsigned k)
{
return Rational(factorial<Integer>(n), factorial<Integer>(k) * factorial<Integer>(n - k));
}
inline mpz_class pow(mpz_class i, unsigned p)
{
mpz_class result;
mpz_pow_ui(result.get_mpz_t(), i.get_mpz_t(), p);
return result;
}
template <class Rational, class Integer = typename Rational::value_type>
Rational Bernoulli(unsigned m)
{
Rational result = 0;
for (unsigned k = 0; k <= m; ++k)
{
Rational inner = 0;
for (unsigned v = 0; v <= k; ++v)
{
Rational term = binomial<Rational, Integer>(k, v) * Rational(pow(Integer(v), m), k + 1);
if (v & 1)
term = -term;
inner += term;
}
result += inner;
}
return result;
}
template <class Rational, class Integer = typename Rational::value_type>
static void BM_bernoulli(benchmark::State& state)
{
int m = state.range(0);
for (auto _ : state)
{
benchmark::DoNotOptimize(Bernoulli<Rational, Integer>(m));
}
}
unsigned allocation_count = 0;
void* (*alloc_func_ptr)(size_t);
void* (*realloc_func_ptr)(void*, size_t, size_t);
void (*free_func_ptr)(void*, size_t);
void* alloc_func(size_t n)
{
++allocation_count;
return (*alloc_func_ptr)(n);
}
void free_func(void* p, size_t n)
{
(*free_func_ptr)(p, n);
}
void* realloc_func(void* p, size_t old, size_t n)
{
++allocation_count;
return (*realloc_func_ptr)(p, old, n);
}
unsigned new_count = 0;
void* operator new(std::size_t n) throw(std::bad_alloc)
{
++new_count;
return std::malloc(n);
}
void operator delete(void* p) throw()
{
std::free(p);
}
void* operator new[](std::size_t n) throw(std::bad_alloc)
{
++new_count;
return std::malloc(n);
}
void operator delete[](void* p) throw()
{
std::free(p);
}
int main()
{
using namespace boost::multiprecision;
mp_get_memory_functions(&alloc_func_ptr, &realloc_func_ptr, &free_func_ptr);
mp_set_memory_functions(&alloc_func, &realloc_func, &free_func);
std::cout << "[table Total Allocation Counts for Bernoulli Number Calculation\n"
"[[m][cpp_rational][mpq_rational][number<rational_adaptor<gmp_int>>][mpq_class]]\n";
for (unsigned m = 2; m < 200; m += 2)
{
std::cout << "[[" << m << "][";
new_count = 0;
Bernoulli<cpp_rational>(m);
std::cout << new_count << "][";
allocation_count = 0;
Bernoulli<mpq_rational>(m);
std::cout << allocation_count << "][";
allocation_count = 0;
Bernoulli<number<rational_adaptor<gmp_int>>>(m);
std::cout << allocation_count << "][";
allocation_count = 0;
Bernoulli<mpq_class, mpz_class>(m);
std::cout << allocation_count << "]]\n";
}
std::cout << "]\n";
return 0;
}
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