mirror of
https://github.com/OpenRCT2/OpenRCT2
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72 lines
2.3 KiB
C++
72 lines
2.3 KiB
C++
/*****************************************************************************
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* Copyright (c) 2014-2020 OpenRCT2 developers
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*
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* For a complete list of all authors, please refer to contributors.md
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* Interested in contributing? Visit https://github.com/OpenRCT2/OpenRCT2
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*
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* OpenRCT2 is licensed under the GNU General Public License version 3.
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*****************************************************************************/
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#pragma once
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#include <cstddef>
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#include <cstdint>
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#include <limits>
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#include <type_traits>
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namespace Numerics
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{
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/**
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* Bitwise left rotate
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* @tparam _UIntType unsigned integral type
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* @param x value
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* @param shift positions to shift
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* @return rotated value
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*/
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template<typename _UIntType> static constexpr _UIntType rol(_UIntType x, size_t shift)
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{
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static_assert(std::is_unsigned<_UIntType>::value, "result_type must be an unsigned integral type");
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using limits = typename std::numeric_limits<_UIntType>;
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return ((static_cast<_UIntType>(x) << shift) | (static_cast<_UIntType>(x) >> (limits::digits - shift)));
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}
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/**
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* Bitwise left rotate of lowest 4 bits
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* @param x unsigned 8-bit integer value
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* @param shift positions to shift
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* @return rotated value
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*/
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[[maybe_unused]] static constexpr uint8_t rol4(uint8_t x, size_t shift)
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{
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x &= 0x0F;
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return (x << shift | x >> (4 - shift)) & 0x0F;
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}
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/**
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* Bitwise right rotate
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* @tparam _UIntType unsigned integral type
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* @param x value
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* @param shift positions to shift
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* @return rotated value
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*/
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template<typename _UIntType> static constexpr _UIntType ror(_UIntType x, size_t shift)
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{
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static_assert(std::is_unsigned<_UIntType>::value, "result_type must be an unsigned integral type");
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using limits = std::numeric_limits<_UIntType>;
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return ((static_cast<_UIntType>(x) >> shift) | (static_cast<_UIntType>(x) << (limits::digits - shift)));
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}
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/**
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* Bitwise right rotate of lowest 4 bits
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* @param x unsigned 8-bit integer value
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* @param shift positions to shift
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* @return rotated value
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*/
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[[maybe_unused]] static constexpr uint8_t ror4(uint8_t x, size_t shift)
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{
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x &= 0x0F;
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return (x >> shift | x << (4 - shift)) & 0x0F;
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}
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} // namespace Numerics
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