// Copyright (c) 2012 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef BASE_MEMORY_ALIGNED_MEMORY_H_ #define BASE_MEMORY_ALIGNED_MEMORY_H_ #include #include #include #include "base/base_export.h" #include "base/bits.h" #include "base/check.h" #include "build/build_config.h" #if defined(COMPILER_MSVC) #include #else #include #endif // A runtime sized aligned allocation can be created: // // float* my_array = static_cast(AlignedAlloc(size, alignment)); // // // ... later, to release the memory: // AlignedFree(my_array); // // Or using unique_ptr: // // std::unique_ptr my_array( // static_cast(AlignedAlloc(size, alignment))); namespace base { // This can be replaced with std::aligned_alloc when we have C++17. // Caveat: std::aligned_alloc requires the size parameter be an integral // multiple of alignment. BASE_EXPORT void* AlignedAlloc(size_t size, size_t alignment); inline void AlignedFree(void* ptr) { #if defined(COMPILER_MSVC) _aligned_free(ptr); #else free(ptr); #endif } // Deleter for use with unique_ptr. E.g., use as // std::unique_ptr foo; struct AlignedFreeDeleter { inline void operator()(void* ptr) const { AlignedFree(ptr); } }; #ifdef __has_builtin #define SUPPORTS_BUILTIN_IS_ALIGNED (__has_builtin(__builtin_is_aligned)) #else #define SUPPORTS_BUILTIN_IS_ALIGNED 0 #endif inline bool IsAligned(uintptr_t val, size_t alignment) { // If the compiler supports builtin alignment checks prefer them. #if SUPPORTS_BUILTIN_IS_ALIGNED return __builtin_is_aligned(val, alignment); #else DCHECK(bits::IsPowerOfTwo(alignment)) << alignment << " is not a power of 2"; return (val & (alignment - 1)) == 0; #endif } #undef SUPPORTS_BUILTIN_IS_ALIGNED inline bool IsAligned(const void* val, size_t alignment) { return IsAligned(reinterpret_cast(val), alignment); } } // namespace base #endif // BASE_MEMORY_ALIGNED_MEMORY_H_