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50 lines
1.5 KiB
C++
50 lines
1.5 KiB
C++
// -*- C++ -*-
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//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef _LIBCPP___MEMORY_ASSUME_ALIGNED_H
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#define _LIBCPP___MEMORY_ASSUME_ALIGNED_H
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#include <__assert>
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#include <__config>
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#include <__type_traits/is_constant_evaluated.h>
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#include <cstddef>
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#include <cstdint>
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#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
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# pragma GCC system_header
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#endif
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_LIBCPP_BEGIN_NAMESPACE_STD
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template <size_t _Np, class _Tp>
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_LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _Tp* __assume_aligned(_Tp* __ptr) {
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static_assert(_Np != 0 && (_Np & (_Np - 1)) == 0, "std::assume_aligned<N>(p) requires N to be a power of two");
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if (__libcpp_is_constant_evaluated()) {
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(void)__builtin_assume_aligned(__ptr, _Np);
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return __ptr;
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} else {
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_LIBCPP_ASSERT_ARGUMENT_WITHIN_DOMAIN(
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reinterpret_cast<uintptr_t>(__ptr) % _Np == 0, "Alignment assumption is violated");
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return static_cast<_Tp*>(__builtin_assume_aligned(__ptr, _Np));
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}
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}
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#if _LIBCPP_STD_VER >= 20
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template <size_t _Np, class _Tp>
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[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp* assume_aligned(_Tp* __ptr) {
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return std::__assume_aligned<_Np>(__ptr);
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}
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#endif // _LIBCPP_STD_VER >= 20
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_LIBCPP_END_NAMESPACE_STD
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#endif // _LIBCPP___MEMORY_ASSUME_ALIGNED_H
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