4f15267d3d
This change is almost fully mechanical. The only interesting change is in `generate_feature_test_macro_components.py` to generate `_LIBCPP_STD_VER >=` instead. To avoid churn in the git-blame this commit should be added to the `.git-blame-ignore-revs` once committed. Reviewed By: ldionne, var-const, #libc Spies: jloser, libcxx-commits, arichardson, arphaman, wenlei Differential Revision: https://reviews.llvm.org/D143962
56 lines
1.6 KiB
C++
56 lines
1.6 KiB
C++
// -*- C++ -*-
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef _LIBCPP___BIT_BYTESWAP_H
|
|
#define _LIBCPP___BIT_BYTESWAP_H
|
|
|
|
#include <__concepts/arithmetic.h>
|
|
#include <__config>
|
|
#include <cstdint>
|
|
#include <cstdlib>
|
|
|
|
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
|
|
# pragma GCC system_header
|
|
#endif
|
|
|
|
_LIBCPP_BEGIN_NAMESPACE_STD
|
|
|
|
#if _LIBCPP_STD_VER >= 23
|
|
|
|
template <integral _Tp>
|
|
_LIBCPP_HIDE_FROM_ABI constexpr _Tp byteswap(_Tp __val) noexcept {
|
|
|
|
if constexpr (sizeof(_Tp) == 1) {
|
|
return __val;
|
|
} else if constexpr (sizeof(_Tp) == 2) {
|
|
return __builtin_bswap16(__val);
|
|
} else if constexpr (sizeof(_Tp) == 4) {
|
|
return __builtin_bswap32(__val);
|
|
} else if constexpr (sizeof(_Tp) == 8) {
|
|
return __builtin_bswap64(__val);
|
|
#ifndef _LIBCPP_HAS_NO_INT128
|
|
} else if constexpr (sizeof(_Tp) == 16) {
|
|
#if __has_builtin(__builtin_bswap128)
|
|
return __builtin_bswap128(__val);
|
|
#else
|
|
return static_cast<_Tp>(byteswap(static_cast<uint64_t>(__val))) << 64 |
|
|
static_cast<_Tp>(byteswap(static_cast<uint64_t>(__val >> 64)));
|
|
#endif // __has_builtin(__builtin_bswap128)
|
|
#endif // _LIBCPP_HAS_NO_INT128
|
|
} else {
|
|
static_assert(sizeof(_Tp) == 0, "byteswap is unimplemented for integral types of this size");
|
|
}
|
|
}
|
|
|
|
#endif // _LIBCPP_STD_VER >= 23
|
|
|
|
_LIBCPP_END_NAMESPACE_STD
|
|
|
|
#endif // _LIBCPP___BIT_BYTESWAP_H
|