| 1 | // Test for boost/core/bit.hpp (countr_zero, countr_one) |
|---|---|
| 2 | // |
| 3 | // Copyright 2020 Peter Dimov |
| 4 | // Distributed under the Boost Software License, Version 1.0. |
| 5 | // https://www.boost.org/LICENSE_1_0.txt |
| 6 | |
| 7 | #include <boost/core/bit.hpp> |
| 8 | #include <boost/core/lightweight_test.hpp> |
| 9 | #include <boost/core/detail/splitmix64.hpp> |
| 10 | #include <boost/cstdint.hpp> |
| 11 | #include <limits> |
| 12 | |
| 13 | template<class T> void test_countr( T x ) |
| 14 | { |
| 15 | x |= 1; |
| 16 | |
| 17 | for( int i = 0; i <= std::numeric_limits<T>::digits; ++i, x = static_cast<T>( x << 1 ) ) |
| 18 | { |
| 19 | BOOST_TEST_EQ( boost::core::countr_zero( x ), i ); |
| 20 | BOOST_TEST_EQ( boost::core::countr_one( static_cast<T>( ~x ) ), i ); |
| 21 | } |
| 22 | } |
| 23 | |
| 24 | int main() |
| 25 | { |
| 26 | test_countr( x: static_cast<unsigned char>( 0 ) ); |
| 27 | test_countr( x: static_cast<unsigned short>( 0 ) ); |
| 28 | test_countr( x: static_cast<unsigned int>( 0 ) ); |
| 29 | test_countr( x: static_cast<unsigned long>( 0 ) ); |
| 30 | test_countr( x: static_cast<boost::ulong_long_type>( 0 ) ); |
| 31 | |
| 32 | boost::detail::splitmix64 rng; |
| 33 | |
| 34 | for( int i = 0; i < 1000; ++i ) |
| 35 | { |
| 36 | boost::uint64_t x = rng(); |
| 37 | |
| 38 | test_countr( x: static_cast<unsigned char>( x ) ); |
| 39 | test_countr( x: static_cast<unsigned short>( x ) ); |
| 40 | test_countr( x: static_cast<unsigned int>( x ) ); |
| 41 | test_countr( x: static_cast<unsigned long>( x ) ); |
| 42 | test_countr( x: static_cast<boost::ulong_long_type>( x ) ); |
| 43 | } |
| 44 | |
| 45 | return boost::report_errors(); |
| 46 | } |
| 47 |