c292b6066c
This supersedes and incoroporates content from both D108906 and D54966, and also some original content. Co-Authored-by: Marshall Clow <mclow.lists@gmail.com> Co-Authored-by: Gonzalo Brito Gadeschi Differential Revision: https://reviews.llvm.org/D118938
47 lines
1.3 KiB
C++
47 lines
1.3 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___MEMORY_ASSUME_ALIGNED_H
|
|
#define _LIBCPP___MEMORY_ASSUME_ALIGNED_H
|
|
|
|
#include <__assert>
|
|
#include <__config>
|
|
#include <cstddef>
|
|
#include <cstdint>
|
|
#include <type_traits> // for is_constant_evaluated()
|
|
|
|
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
|
|
# pragma GCC system_header
|
|
#endif
|
|
|
|
_LIBCPP_BEGIN_NAMESPACE_STD
|
|
|
|
#if _LIBCPP_STD_VER > 17
|
|
|
|
template <size_t _Np, class _Tp>
|
|
[[nodiscard]]
|
|
_LIBCPP_HIDE_FROM_ABI
|
|
constexpr _Tp* assume_aligned(_Tp* __ptr) {
|
|
static_assert(_Np != 0 && (_Np & (_Np - 1)) == 0,
|
|
"std::assume_aligned<N>(p) requires N to be a power of two");
|
|
|
|
if (is_constant_evaluated()) {
|
|
return __ptr;
|
|
} else {
|
|
_LIBCPP_ASSERT(reinterpret_cast<uintptr_t>(__ptr) % _Np == 0, "Alignment assumption is violated");
|
|
return static_cast<_Tp*>(__builtin_assume_aligned(__ptr, _Np));
|
|
}
|
|
}
|
|
|
|
#endif // _LIBCPP_STD_VER > 17
|
|
|
|
_LIBCPP_END_NAMESPACE_STD
|
|
|
|
#endif // _LIBCPP___MEMORY_ASSUME_ALIGNED_H
|