1*4bdff4beSrobert // -*- C++ -*- 2*4bdff4beSrobert //===----------------------------------------------------------------------===// 3*4bdff4beSrobert // 4*4bdff4beSrobert // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5*4bdff4beSrobert // See https://llvm.org/LICENSE.txt for license information. 6*4bdff4beSrobert // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7*4bdff4beSrobert // 8*4bdff4beSrobert //===----------------------------------------------------------------------===// 9*4bdff4beSrobert 10*4bdff4beSrobert #ifndef _LIBCPP___BIT_BYTESWAP_H 11*4bdff4beSrobert #define _LIBCPP___BIT_BYTESWAP_H 12*4bdff4beSrobert 13*4bdff4beSrobert #include <__concepts/arithmetic.h> 14*4bdff4beSrobert #include <__config> 15*4bdff4beSrobert #include <cstdint> 16*4bdff4beSrobert #include <cstdlib> 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 <integral _Tp> byteswap(_Tp __val)27*4bdff4beSrobert_LIBCPP_HIDE_FROM_ABI constexpr _Tp byteswap(_Tp __val) noexcept { 28*4bdff4beSrobert 29*4bdff4beSrobert if constexpr (sizeof(_Tp) == 1) { 30*4bdff4beSrobert return __val; 31*4bdff4beSrobert } else if constexpr (sizeof(_Tp) == 2) { 32*4bdff4beSrobert return __builtin_bswap16(__val); 33*4bdff4beSrobert } else if constexpr (sizeof(_Tp) == 4) { 34*4bdff4beSrobert return __builtin_bswap32(__val); 35*4bdff4beSrobert } else if constexpr (sizeof(_Tp) == 8) { 36*4bdff4beSrobert return __builtin_bswap64(__val); 37*4bdff4beSrobert #ifndef _LIBCPP_HAS_NO_INT128 38*4bdff4beSrobert } else if constexpr (sizeof(_Tp) == 16) { 39*4bdff4beSrobert #if __has_builtin(__builtin_bswap128) 40*4bdff4beSrobert return __builtin_bswap128(__val); 41*4bdff4beSrobert #else 42*4bdff4beSrobert return static_cast<_Tp>(byteswap(static_cast<uint64_t>(__val))) << 64 | 43*4bdff4beSrobert static_cast<_Tp>(byteswap(static_cast<uint64_t>(__val >> 64))); 44*4bdff4beSrobert #endif // __has_builtin(__builtin_bswap128) 45*4bdff4beSrobert #endif // _LIBCPP_HAS_NO_INT128 46*4bdff4beSrobert } else { 47*4bdff4beSrobert static_assert(sizeof(_Tp) == 0, "byteswap is unimplemented for integral types of this size"); 48*4bdff4beSrobert } 49*4bdff4beSrobert } 50*4bdff4beSrobert 51*4bdff4beSrobert #endif // _LIBCPP_STD_VER > 20 52*4bdff4beSrobert 53*4bdff4beSrobert _LIBCPP_END_NAMESPACE_STD 54*4bdff4beSrobert 55*4bdff4beSrobert #endif // _LIBCPP___BIT_BYTESWAP_H 56