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Diffstat (limited to 'boost/atomic/detail/fp_ops_generic.hpp')
-rw-r--r-- | boost/atomic/detail/fp_ops_generic.hpp | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/boost/atomic/detail/fp_ops_generic.hpp b/boost/atomic/detail/fp_ops_generic.hpp new file mode 100644 index 0000000000..b83e85a359 --- /dev/null +++ b/boost/atomic/detail/fp_ops_generic.hpp @@ -0,0 +1,83 @@ +/* + * 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_0.txt) + * + * Copyright (c) 2018 Andrey Semashev + */ +/*! + * \file atomic/detail/fp_ops_generic.hpp + * + * This header contains generic implementation of the floating point atomic operations. + */ + +#ifndef BOOST_ATOMIC_DETAIL_FP_OPS_GENERIC_HPP_INCLUDED_ +#define BOOST_ATOMIC_DETAIL_FP_OPS_GENERIC_HPP_INCLUDED_ + +#include <cstddef> +#include <boost/memory_order.hpp> +#include <boost/atomic/detail/config.hpp> +#include <boost/atomic/detail/bitwise_fp_cast.hpp> +#include <boost/atomic/detail/storage_type.hpp> +#include <boost/atomic/detail/fp_operations_fwd.hpp> + +#ifdef BOOST_HAS_PRAGMA_ONCE +#pragma once +#endif + +namespace boost { +namespace atomics { +namespace detail { + +//! Generic implementation of floating point operations +template< typename Base, typename Value, std::size_t Size > +struct generic_fp_operations : + public Base +{ + typedef Base base_type; + typedef typename base_type::storage_type storage_type; + typedef Value value_type; + + static BOOST_FORCEINLINE value_type fetch_add(storage_type volatile& storage, value_type v, memory_order order) BOOST_NOEXCEPT + { + storage_type old_storage, new_storage; + value_type old_val, new_val; + atomics::detail::non_atomic_load(storage, old_storage); + do + { + old_val = atomics::detail::bitwise_fp_cast< value_type >(old_storage); + new_val = old_val + v; + new_storage = atomics::detail::bitwise_fp_cast< storage_type >(new_val); + } + while (!base_type::compare_exchange_weak(storage, old_storage, new_storage, order, memory_order_relaxed)); + return old_val; + } + + static BOOST_FORCEINLINE value_type fetch_sub(storage_type volatile& storage, value_type v, memory_order order) BOOST_NOEXCEPT + { + storage_type old_storage, new_storage; + value_type old_val, new_val; + atomics::detail::non_atomic_load(storage, old_storage); + do + { + old_val = atomics::detail::bitwise_fp_cast< value_type >(old_storage); + new_val = old_val - v; + new_storage = atomics::detail::bitwise_fp_cast< storage_type >(new_val); + } + while (!base_type::compare_exchange_weak(storage, old_storage, new_storage, order, memory_order_relaxed)); + return old_val; + } +}; + +// Default fp_operations template definition will be used unless specialized for a specific platform +template< typename Base, typename Value, std::size_t Size > +struct fp_operations< Base, Value, Size, true > : + public generic_fp_operations< Base, Value, Size > +{ +}; + +} // namespace detail +} // namespace atomics +} // namespace boost + +#endif // BOOST_ATOMIC_DETAIL_FP_OPS_GENERIC_HPP_INCLUDED_ |