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1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef _LIBCPP___BIT_BIT_CEIL_H10#define _LIBCPP___BIT_BIT_CEIL_H11 12#include <__assert>13#include <__bit/countl.h>14#include <__config>15#include <__type_traits/integer_traits.h>16#include <limits>17 18#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)19# pragma GCC system_header20#endif21 22_LIBCPP_BEGIN_NAMESPACE_STD23 24#if _LIBCPP_STD_VER >= 1725 26template <class _Tp>27[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp __bit_ceil(_Tp __t) noexcept {28 if (__t < 2)29 return 1;30 const unsigned __n = numeric_limits<_Tp>::digits - std::__countl_zero((_Tp)(__t - 1u));31 _LIBCPP_ASSERT_ARGUMENT_WITHIN_DOMAIN(__n != numeric_limits<_Tp>::digits, "Bad input to bit_ceil");32 33 if constexpr (sizeof(_Tp) >= sizeof(unsigned))34 return _Tp{1} << __n;35 else {36 const unsigned __extra = numeric_limits<unsigned>::digits - numeric_limits<_Tp>::digits;37 const unsigned __ret_val = 1u << (__n + __extra);38 return (_Tp)(__ret_val >> __extra);39 }40}41 42# if _LIBCPP_STD_VER >= 2043 44template <__unsigned_integer _Tp>45[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp bit_ceil(_Tp __t) noexcept {46 return std::__bit_ceil(__t);47}48 49# endif // _LIBCPP_STD_VER >= 2050#endif // _LIBCPP_STD_VER >= 1751 52_LIBCPP_END_NAMESPACE_STD53 54#endif // _LIBCPP___BIT_BIT_CEIL_H55