1 ///////////////////////////////////////////////////////////////
2 // Copyright 2012 John Maddock. Distributed under the Boost
3 // Software License, Version 1.0. (See accompanying file
4 // LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt
7 // Compare results of truncated left shift to gmp, see:
8 // https://svn.boost.org/trac/boost/ticket/12790
12 #define _SCL_SECURE_NO_WARNINGS
15 #include <boost/multiprecision/gmp.hpp>
16 #include <boost/multiprecision/cpp_int.hpp>
17 #include <boost/random/mersenne_twister.hpp>
18 #include <boost/random/uniform_int.hpp>
19 #include <boost/timer.hpp>
22 #if !defined(TEST1) && !defined(TEST2) && !defined(TEST3)
29 T generate_random(unsigned bits_wanted)
31 static boost::random::mt19937 gen;
32 typedef boost::random::mt19937::result_type random_type;
36 if (std::numeric_limits<T>::is_bounded && (bits_wanted == (unsigned)std::numeric_limits<T>::digits))
38 max_val = (std::numeric_limits<T>::max)();
39 digits = std::numeric_limits<T>::digits;
43 max_val = T(1) << bits_wanted;
47 unsigned bits_per_r_val = std::numeric_limits<random_type>::digits - 1;
48 while ((random_type(1) << bits_per_r_val) > (gen.max)())
51 unsigned terms_needed = digits / bits_per_r_val + 1;
54 for (unsigned i = 0; i < terms_needed; ++i)
64 void test_value(const T& val)
66 boost::multiprecision::mpz_int z(val.str()), mask(1);
67 mask <<= std::numeric_limits<T>::digits;
70 for (unsigned i = 0; i <= std::numeric_limits<T>::digits + 2; ++i)
72 BOOST_CHECK_EQUAL((val << i).str(), boost::multiprecision::mpz_int(((z << i) & mask)).str());
76 void test(const boost::mpl::int_<200>&) {}
79 void test(boost::mpl::int_<N> const&)
81 test(boost::mpl::int_<N + 4>());
83 typedef boost::multiprecision::number<boost::multiprecision::cpp_int_backend<N, N, boost::multiprecision::unsigned_magnitude>, boost::multiprecision::et_off> mp_type;
85 std::cout << "Running tests for precision: " << N << std::endl;
90 for (unsigned i = 0; i < 1000; ++i)
91 test_value(generate_random<mp_type>(std::numeric_limits<mp_type>::digits));
96 test(boost::mpl::int_<24>());
97 return boost::report_errors();