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 arithmetic results using fixed_int to GMP results.
11 #define _SCL_SECURE_NO_WARNINGS
14 #include <boost/multiprecision/cpp_int.hpp>
16 #include <boost/random/mersenne_twister.hpp>
17 #include <boost/random/uniform_int.hpp>
20 T generate_random(unsigned bits_wanted)
22 static boost::random::mt19937 gen;
23 typedef boost::random::mt19937::result_type random_type;
27 if (std::numeric_limits<T>::is_bounded && (bits_wanted == (unsigned)std::numeric_limits<T>::digits))
29 max_val = (std::numeric_limits<T>::max)();
30 digits = std::numeric_limits<T>::digits;
34 max_val = T(1) << bits_wanted;
38 unsigned bits_per_r_val = std::numeric_limits<random_type>::digits - 1;
39 while ((random_type(1) << bits_per_r_val) > (gen.max)())
42 unsigned terms_needed = digits / bits_per_r_val + 1;
45 for (unsigned i = 0; i < terms_needed; ++i)
54 template <class Number>
55 void test_signed_overflow(Number a, Number b, const boost::mpl::true_&)
58 BOOST_CHECK_THROW(Number(a * b), std::overflow_error);
60 BOOST_CHECK(Number(a * b) >= (std::numeric_limits<Number>::min)());
62 template <class Number>
63 void test_signed_overflow(Number a, Number b, const boost::mpl::false_&)
67 template <class Number>
70 using namespace boost::multiprecision;
71 typedef Number test_type;
73 if (std::numeric_limits<test_type>::is_bounded)
75 test_type val = (std::numeric_limits<test_type>::max)();
76 #ifndef BOOST_NO_EXCEPTIONS
77 BOOST_CHECK_THROW(++val, std::overflow_error);
78 val = (std::numeric_limits<test_type>::max)();
79 BOOST_CHECK_THROW(test_type(1 + val), std::overflow_error);
80 BOOST_CHECK_THROW(test_type(val + 1), std::overflow_error);
81 BOOST_CHECK_THROW(test_type(2 * val), std::overflow_error);
84 BOOST_CHECK_THROW(test_type(2 * val), std::overflow_error);
86 if (std::numeric_limits<test_type>::is_signed)
88 val = (std::numeric_limits<test_type>::min)();
89 BOOST_CHECK_THROW(--val, std::overflow_error);
90 val = (std::numeric_limits<test_type>::min)();
91 BOOST_CHECK_THROW(test_type(val - 1), std::overflow_error);
92 BOOST_CHECK_THROW(test_type(2 * val), std::overflow_error);
95 BOOST_CHECK_THROW(test_type(2 * val), std::overflow_error);
99 val = (std::numeric_limits<test_type>::min)();
100 BOOST_CHECK_THROW(--val, std::range_error);
101 val = (std::numeric_limits<test_type>::min)();
102 BOOST_CHECK_THROW(test_type(val - 1), std::range_error);
106 // Test overflow in random values:
108 for (unsigned bits = 30; bits < std::numeric_limits<test_type>::digits; bits += 30)
110 for (unsigned i = 0; i < 100; ++i)
112 val = static_cast<test_type>(generate_random<cpp_int>(bits));
113 test_type val2 = 1 + (std::numeric_limits<test_type>::max)() / val;
114 BOOST_CHECK_THROW(test_type(val2 * val), std::overflow_error);
115 test_signed_overflow(val2, val, boost::mpl::bool_<std::numeric_limits<test_type>::is_signed>());
117 BOOST_CHECK(cpp_int(val2) * cpp_int(val) <= cpp_int((std::numeric_limits<test_type>::max)()));
118 BOOST_CHECK(val2 * val <= (std::numeric_limits<test_type>::max)());
119 val2 = (std::numeric_limits<test_type>::max)() - val;
121 BOOST_CHECK_THROW(test_type(val2 + val), std::overflow_error);
122 BOOST_CHECK((val2 - 1) + val == (std::numeric_limits<test_type>::max)());
123 if (std::numeric_limits<test_type>::is_signed)
125 val2 = (std::numeric_limits<test_type>::min)() + val;
127 BOOST_CHECK_THROW(test_type(val2 - val), std::overflow_error);
129 BOOST_CHECK(val2 - val == (std::numeric_limits<test_type>::min)());
131 unsigned shift = std::numeric_limits<test_type>::digits - msb(val);
132 BOOST_CHECK_THROW((val << shift) > 0, std::overflow_error);
137 #ifndef BOOST_NO_EXCEPTIONS
138 if (std::numeric_limits<test_type>::is_signed)
142 BOOST_CHECK_THROW(test_type(a | b), std::range_error);
143 BOOST_CHECK_THROW(test_type(a & b), std::range_error);
144 BOOST_CHECK_THROW(test_type(a ^ b), std::range_error);
148 // Constructing from a negative value is not allowed:
149 BOOST_CHECK_THROW(test_type(-2), std::range_error);
150 BOOST_CHECK_THROW(test_type("-2"), std::range_error);
152 if (std::numeric_limits<test_type>::digits < std::numeric_limits<long long>::digits)
154 long long llm = (std::numeric_limits<long long>::max)();
156 BOOST_CHECK_THROW(t = llm, std::range_error);
157 BOOST_CHECK_THROW(t = static_cast<test_type>(llm), std::range_error);
158 unsigned long long ullm = (std::numeric_limits<unsigned long long>::max)();
159 BOOST_CHECK_THROW(t = ullm, std::range_error);
160 BOOST_CHECK_THROW(t = static_cast<test_type>(ullm), std::range_error);
162 static const checked_uint512_t big = (std::numeric_limits<checked_uint512_t>::max)();
163 BOOST_CHECK_THROW(t = static_cast<test_type>(big), std::range_error);
168 BOOST_CHECK_THROW(test_type("12A"), std::runtime_error);
169 BOOST_CHECK_THROW(test_type("0658"), std::runtime_error);
171 if (std::numeric_limits<test_type>::is_signed)
173 BOOST_CHECK_THROW(test_type(-2).str(0, std::ios_base::hex), std::runtime_error);
174 BOOST_CHECK_THROW(test_type(-2).str(0, std::ios_base::oct), std::runtime_error);
181 using namespace boost::multiprecision;
183 test<number<cpp_int_backend<0, 0, signed_magnitude, checked> > >();
184 test<checked_int512_t>();
185 test<checked_uint512_t>();
186 test<number<cpp_int_backend<32, 32, signed_magnitude, checked, void> > >();
187 test<number<cpp_int_backend<32, 32, unsigned_magnitude, checked, void> > >();
190 // We also need to test type with "odd" bit counts in order to ensure full code coverage:
192 test<number<cpp_int_backend<528, 528, signed_magnitude, checked, void> > >();
193 test<number<cpp_int_backend<528, 528, unsigned_magnitude, checked, void> > >();
194 test<number<cpp_int_backend<48, 48, signed_magnitude, checked, void> > >();
195 test<number<cpp_int_backend<48, 48, unsigned_magnitude, checked, void> > >();
196 return boost::report_errors();