253 lines
8.0 KiB
C++
253 lines
8.0 KiB
C++
///\file
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/******************************************************************************
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The MIT License(MIT)
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Embedded Template Library.
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https://github.com/ETLCPP/etl
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https://www.etlcpp.com
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Copyright(c) 2021 John Wellbelove
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files(the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions :
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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.
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******************************************************************************/
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#ifndef ETL_BIT_INCLUDED
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#define ETL_BIT_INCLUDED
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#include "platform.h"
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#include "type_traits.h"
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#include "binary.h"
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#include "integral_limits.h"
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#include "endianness.h"
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#include "type_traits.h"
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#include <string.h>
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#if ETL_USING_CPP20 && ETL_USING_STL
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#include <bit>
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#endif
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namespace etl
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{
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//***************************************************************************
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/// bit_cast - Type to different type.
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//***************************************************************************
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template <typename TDestination, typename TSource>
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ETL_NODISCARD
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typename etl::enable_if<!(etl::is_integral<TDestination>::value&& etl::is_integral<TSource>::value) &&
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(sizeof(TDestination) == sizeof(TSource)) &&
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etl::is_trivially_copyable<TSource>::value &&
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etl::is_trivially_copyable<TDestination>::value, TDestination>::type
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bit_cast(const TSource& source) ETL_NOEXCEPT
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{
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TDestination destination;
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memcpy(&destination, &source, sizeof(TDestination));
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return destination;
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}
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//***************************************************************************
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/// bit_cast - Integral to integral
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//***************************************************************************
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template <typename TDestination, typename TSource>
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ETL_NODISCARD
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ETL_CONSTEXPR14
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typename etl::enable_if<(etl::is_integral<TDestination>::value && etl::is_integral<TSource>::value) &&
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(sizeof(TDestination) == sizeof(TSource)), TDestination>::type
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bit_cast(const TSource& source) ETL_NOEXCEPT
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{
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return static_cast<TDestination>(source);
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}
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//***************************************************************************
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/// byteswap
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//***************************************************************************
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template <typename T>
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ETL_CONSTEXPR14
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typename etl::enable_if<etl::is_integral<T>::value, T>::type
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byteswap(T value) ETL_NOEXCEPT
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{
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return etl::reverse_bytes(value);
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}
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//***************************************************************************
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/// has_single_bit
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//***************************************************************************
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template <typename T>
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ETL_NODISCARD ETL_CONSTEXPR14
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typename etl::enable_if<etl::is_unsigned<T>::value, bool>::type has_single_bit(T value) ETL_NOEXCEPT
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{
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return (value & (value - 1)) == 0;
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}
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//***************************************************************************
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/// countl_zero
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//***************************************************************************
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template <typename T>
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ETL_NODISCARD ETL_CONSTEXPR14
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typename etl::enable_if<etl::is_unsigned<T>::value, int>::type
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countl_zero(T value) ETL_NOEXCEPT
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{
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return etl::count_leading_zeros(value);
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}
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//***************************************************************************
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/// countl_one
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//***************************************************************************
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template <typename T>
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ETL_NODISCARD ETL_CONSTEXPR14
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typename etl::enable_if<etl::is_unsigned<T>::value, int>::type
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countl_one(T value) ETL_NOEXCEPT
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{
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return etl::count_leading_ones(value);
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}
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//***************************************************************************
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/// countr_zero
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//***************************************************************************
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template <typename T>
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ETL_NODISCARD ETL_CONSTEXPR14
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typename etl::enable_if<etl::is_unsigned<T>::value, int>::type
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countr_zero(T value) ETL_NOEXCEPT
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{
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return etl::count_trailing_zeros(value);
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}
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//***************************************************************************
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/// countr_one
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//***************************************************************************
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template <typename T>
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ETL_NODISCARD ETL_CONSTEXPR14
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typename etl::enable_if<etl::is_unsigned<T>::value, int>::type
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countr_one(T value) ETL_NOEXCEPT
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{
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return etl::count_trailing_ones(value);;
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}
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//***************************************************************************
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/// bit_width
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//***************************************************************************
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template <typename T>
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ETL_CONSTEXPR14
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typename etl::enable_if<etl::is_unsigned<T>::value, T>::type
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bit_width(T value) ETL_NOEXCEPT
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{
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#if ETL_USING_CPP20 && ETL_USING_STL
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return std::bit_width(value);
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#else
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return etl::integral_limits<T>::bits - etl::countl_zero(value);
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#endif
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}
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//***************************************************************************
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/// bit_ceil
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//***************************************************************************
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template <typename T>
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ETL_NODISCARD ETL_CONSTEXPR14
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typename etl::enable_if<etl::is_unsigned<T>::value, T>::type
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bit_ceil(T value)
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{
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#if ETL_USING_CPP20 && ETL_USING_STL
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return std::bit_ceil(value);
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#else
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if (value == T(0))
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{
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return T(1);
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}
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else
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{
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return T(1) << etl::bit_width(T(value - T(1)));
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}
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#endif
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}
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//***************************************************************************
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/// bit_floor
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//***************************************************************************
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template <typename T>
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ETL_NODISCARD ETL_CONSTEXPR14
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typename etl::enable_if<etl::is_unsigned<T>::value, T>::type
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bit_floor(T value) ETL_NOEXCEPT
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{
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#if ETL_USING_CPP20 && ETL_USING_STL
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return std::bit_floor(value);
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#else
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if (value == T(0))
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{
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return T(0);
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}
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else
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{
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return T(1) << (etl::bit_width(value) - T(1));
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}
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#endif
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}
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//***************************************************************************
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/// rotl
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//***************************************************************************
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template <typename T>
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ETL_NODISCARD ETL_CONSTEXPR14
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typename etl::enable_if<etl::is_unsigned<T>::value, T>::type
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rotl(T value, int n) ETL_NOEXCEPT
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{
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if (n < 0)
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{
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return etl::rotate_right(value, -n);
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}
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else
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{
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return etl::rotate_left(value, n);
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}
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}
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//***************************************************************************
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/// rotr
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//***************************************************************************
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template <typename T>
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ETL_NODISCARD ETL_CONSTEXPR14
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typename etl::enable_if<etl::is_unsigned<T>::value, T>::type
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rotr(T value, int n) ETL_NOEXCEPT
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{
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if (n < 0)
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{
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return etl::rotate_left(value, -n);
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}
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else
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{
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return etl::rotate_right(value, n);
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}
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}
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//***************************************************************************
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/// popcount
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//***************************************************************************
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template <typename T>
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ETL_NODISCARD ETL_CONSTEXPR14
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typename etl::enable_if<etl::is_unsigned<T>::value, int>::type
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popcount(T value) ETL_NOEXCEPT
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{
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return etl::count_bits(value);
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}
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}
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#endif
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