1*4bdff4beSrobert //===----------------------------------------------------------------------===// 2*4bdff4beSrobert // 3*4bdff4beSrobert // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*4bdff4beSrobert // See https://llvm.org/LICENSE.txt for license information. 5*4bdff4beSrobert // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*4bdff4beSrobert // 7*4bdff4beSrobert //===----------------------------------------------------------------------===// 8*4bdff4beSrobert 9*4bdff4beSrobert #ifndef _LIBCPP___BIT_BIT_CEIL_H 10*4bdff4beSrobert #define _LIBCPP___BIT_BIT_CEIL_H 11*4bdff4beSrobert 12*4bdff4beSrobert #include <__assert> 13*4bdff4beSrobert #include <__bit/countl.h> 14*4bdff4beSrobert #include <__concepts/arithmetic.h> 15*4bdff4beSrobert #include <__config> 16*4bdff4beSrobert #include <limits> 17*4bdff4beSrobert 18*4bdff4beSrobert #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 19*4bdff4beSrobert # pragma GCC system_header 20*4bdff4beSrobert #endif 21*4bdff4beSrobert 22*4bdff4beSrobert _LIBCPP_BEGIN_NAMESPACE_STD 23*4bdff4beSrobert 24*4bdff4beSrobert #if _LIBCPP_STD_VER >= 20 25*4bdff4beSrobert 26*4bdff4beSrobert template <__libcpp_unsigned_integer _Tp> bit_ceil(_Tp __t)27*4bdff4beSrobert_LIBCPP_HIDE_FROM_ABI constexpr _Tp bit_ceil(_Tp __t) noexcept { 28*4bdff4beSrobert if (__t < 2) 29*4bdff4beSrobert return 1; 30*4bdff4beSrobert const unsigned __n = numeric_limits<_Tp>::digits - std::countl_zero((_Tp)(__t - 1u)); 31*4bdff4beSrobert _LIBCPP_ASSERT(__n != numeric_limits<_Tp>::digits, "Bad input to bit_ceil"); 32*4bdff4beSrobert 33*4bdff4beSrobert if constexpr (sizeof(_Tp) >= sizeof(unsigned)) 34*4bdff4beSrobert return _Tp{1} << __n; 35*4bdff4beSrobert else { 36*4bdff4beSrobert const unsigned __extra = numeric_limits<unsigned>::digits - numeric_limits<_Tp>::digits; 37*4bdff4beSrobert const unsigned __retVal = 1u << (__n + __extra); 38*4bdff4beSrobert return (_Tp)(__retVal >> __extra); 39*4bdff4beSrobert } 40*4bdff4beSrobert } 41*4bdff4beSrobert 42*4bdff4beSrobert #endif // _LIBCPP_STD_VER >= 20 43*4bdff4beSrobert 44*4bdff4beSrobert _LIBCPP_END_NAMESPACE_STD 45*4bdff4beSrobert 46*4bdff4beSrobert #endif // _LIBCPP___BIT_BIT_CEIL_H 47