106c3fb27SDimitry Andric //===----------------------------------------------------------------------===// 206c3fb27SDimitry Andric // 306c3fb27SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 406c3fb27SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 506c3fb27SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 606c3fb27SDimitry Andric // 706c3fb27SDimitry Andric //===----------------------------------------------------------------------===// 806c3fb27SDimitry Andric 906c3fb27SDimitry Andric #ifndef _LIBCPP___MEMORY_ALIGNED_ALLOC_H 1006c3fb27SDimitry Andric #define _LIBCPP___MEMORY_ALIGNED_ALLOC_H 1106c3fb27SDimitry Andric 1206c3fb27SDimitry Andric #include <__config> 1306c3fb27SDimitry Andric #include <cstddef> 1406c3fb27SDimitry Andric #include <cstdlib> 1506c3fb27SDimitry Andric 1606c3fb27SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 1706c3fb27SDimitry Andric # pragma GCC system_header 1806c3fb27SDimitry Andric #endif 1906c3fb27SDimitry Andric 2006c3fb27SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD 2106c3fb27SDimitry Andric 2206c3fb27SDimitry Andric #ifndef _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION 2306c3fb27SDimitry Andric 2406c3fb27SDimitry Andric // Low-level helpers to call the aligned allocation and deallocation functions 2506c3fb27SDimitry Andric // on the target platform. This is used to implement libc++'s own memory 2606c3fb27SDimitry Andric // allocation routines -- if you need to allocate memory inside the library, 2706c3fb27SDimitry Andric // chances are that you want to use `__libcpp_allocate` instead. 2806c3fb27SDimitry Andric // 2906c3fb27SDimitry Andric // Returns the allocated memory, or `nullptr` on failure. 30*cb14a3feSDimitry Andric inline _LIBCPP_HIDE_FROM_ABI void* __libcpp_aligned_alloc(std::size_t __alignment, std::size_t __size) { 3106c3fb27SDimitry Andric # if defined(_LIBCPP_MSVCRT_LIKE) 3206c3fb27SDimitry Andric return ::_aligned_malloc(__size, __alignment); 3306c3fb27SDimitry Andric # elif _LIBCPP_STD_VER >= 17 && !defined(_LIBCPP_HAS_NO_C11_ALIGNED_ALLOC) 3406c3fb27SDimitry Andric // aligned_alloc() requires that __size is a multiple of __alignment, 3506c3fb27SDimitry Andric // but for C++ [new.delete.general], only states "if the value of an 3606c3fb27SDimitry Andric // alignment argument passed to any of these functions is not a valid 3706c3fb27SDimitry Andric // alignment value, the behavior is undefined". 3806c3fb27SDimitry Andric // To handle calls such as ::operator new(1, std::align_val_t(128)), we 3906c3fb27SDimitry Andric // round __size up to the next multiple of __alignment. 4006c3fb27SDimitry Andric size_t __rounded_size = (__size + __alignment - 1) & ~(__alignment - 1); 4106c3fb27SDimitry Andric // Rounding up could have wrapped around to zero, so we have to add another 4206c3fb27SDimitry Andric // max() ternary to the actual call site to avoid succeeded in that case. 4306c3fb27SDimitry Andric return ::aligned_alloc(__alignment, __size > __rounded_size ? __size : __rounded_size); 4406c3fb27SDimitry Andric # else 4506c3fb27SDimitry Andric void* __result = nullptr; 4606c3fb27SDimitry Andric (void)::posix_memalign(&__result, __alignment, __size); 4706c3fb27SDimitry Andric // If posix_memalign fails, __result is unmodified so we still return `nullptr`. 4806c3fb27SDimitry Andric return __result; 4906c3fb27SDimitry Andric # endif 5006c3fb27SDimitry Andric } 5106c3fb27SDimitry Andric 52*cb14a3feSDimitry Andric inline _LIBCPP_HIDE_FROM_ABI void __libcpp_aligned_free(void* __ptr) { 5306c3fb27SDimitry Andric # if defined(_LIBCPP_MSVCRT_LIKE) 5406c3fb27SDimitry Andric ::_aligned_free(__ptr); 5506c3fb27SDimitry Andric # else 5606c3fb27SDimitry Andric ::free(__ptr); 5706c3fb27SDimitry Andric # endif 5806c3fb27SDimitry Andric } 5906c3fb27SDimitry Andric 6006c3fb27SDimitry Andric #endif // !_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION 6106c3fb27SDimitry Andric 6206c3fb27SDimitry Andric _LIBCPP_END_NAMESPACE_STD 6306c3fb27SDimitry Andric 6406c3fb27SDimitry Andric #endif // _LIBCPP___MEMORY_ALIGNED_ALLOC_H 65