mirror of
https://github.com/boostorg/multiprecision.git
synced 2026-02-13 12:32:18 +00:00
8433c69175
Restrict integer functions to integer types. Improve Miller Rabin performance by filtering out small primes etc. Improve Miller Rabin tests. Change mp_int to tom_int to avoid conflict with global ::mp_Int type. [SVN r77471]
60 lines
2.0 KiB
C++
60 lines
2.0 KiB
C++
///////////////////////////////////////////////////////////////
|
|
// Copyright 2012 John Maddock. 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_
|
|
|
|
#include <boost/multiprecision/gmp.hpp>
|
|
#include <boost/multiprecision/miller_rabin.hpp>
|
|
#include <boost/math/special_functions/prime.hpp>
|
|
#include <iostream>
|
|
#include <iomanip>
|
|
#include "test.hpp"
|
|
|
|
int main()
|
|
{
|
|
//
|
|
// Very simple test program to verify that the GMP's Miller-Rabin
|
|
// implementation and this one agree on whether some random numbers
|
|
// are prime or not. Of course these are probabilistic tests so there's
|
|
// no reason why they should actually agree - except the probability of
|
|
// disagreement for 25 trials is almost infinitely small.
|
|
//
|
|
using namespace boost::random;
|
|
using namespace boost::multiprecision;
|
|
|
|
independent_bits_engine<mt11213b, 256, mpz_int> gen;
|
|
//
|
|
// We must use a different generator for the tests and number generation, otherwise
|
|
// we get false positives. Further we use the same random number engine for the
|
|
// Miller Rabin test as GMP uses internally:
|
|
//
|
|
mt19937 gen2;
|
|
|
|
//
|
|
// Begin by testing the primes in our table as all these should return true:
|
|
//
|
|
for(unsigned i = 1; i < boost::math::max_prime; ++i)
|
|
{
|
|
BOOST_TEST(miller_rabin_test(mpz_int(boost::math::prime(i)), 25, gen));
|
|
}
|
|
//
|
|
// Now test some random values and compare GMP's native routine with ours.
|
|
//
|
|
for(unsigned i = 0; i < 10000; ++i)
|
|
{
|
|
mpz_int n = gen();
|
|
bool is_prime_boost = miller_rabin_test(n, 25, gen2);
|
|
bool is_gmp_prime = mpz_probab_prime_p(n.backend().data(), 25);
|
|
if(is_prime_boost && is_gmp_prime)
|
|
{
|
|
std::cout << "We have a prime: " << std::hex << std::showbase << n << std::endl;
|
|
}
|
|
if(is_prime_boost != is_gmp_prime)
|
|
std::cout << std::hex << std::showbase << "n = " << n << std::endl;
|
|
BOOST_CHECK_EQUAL(is_prime_boost, is_gmp_prime);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|