| /* |
| Simple DirectMedia Layer |
| Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org> |
| |
| This software is provided 'as-is', without any express or implied |
| warranty. In no event will the authors be held liable for any damages |
| arising from the use of this software. |
| |
| Permission is granted to anyone to use this software for any purpose, |
| including commercial applications, and to alter it and redistribute it |
| freely, subject to the following restrictions: |
| |
| 1. The origin of this software must not be misrepresented; you must not |
| claim that you wrote the original software. If you use this software |
| in a product, an acknowledgment in the product documentation would be |
| appreciated but is not required. |
| 2. Altered source versions must be plainly marked as such, and must not be |
| misrepresented as being the original software. |
| 3. This notice may not be removed or altered from any source distribution. |
| */ |
| |
| #include "SDL.h" |
| #include "../SDL_internal.h" |
| |
| /** |
| * \brief Report the alignment this system needs for SIMD allocations. |
| * |
| * This will return the minimum number of bytes to which a pointer must be |
| * aligned to be compatible with SIMD instructions on the current machine. |
| * For example, if the machine supports SSE only, it will return 16, but if |
| * it supports AVX-512F, it'll return 64 (etc). This only reports values for |
| * instruction sets SDL knows about, so if your SDL build doesn't have |
| * SDL_HasAVX512F(), then it might return 16 for the SSE support it sees and |
| * not 64 for the AVX-512 instructions that exist but SDL doesn't know about. |
| * Plan accordingly. |
| */ |
| extern size_t SDL_SIMDGetAlignment(void); |
| |
| /** |
| * \brief Allocate memory in a SIMD-friendly way. |
| * |
| * This will allocate a block of memory that is suitable for use with SIMD |
| * instructions. Specifically, it will be properly aligned and padded for |
| * the system's supported vector instructions. |
| * |
| * The memory returned will be padded such that it is safe to read or write |
| * an incomplete vector at the end of the memory block. This can be useful |
| * so you don't have to drop back to a scalar fallback at the end of your |
| * SIMD processing loop to deal with the final elements without overflowing |
| * the allocated buffer. |
| * |
| * You must free this memory with SDL_FreeSIMD(), not free() or SDL_free() |
| * or delete[], etc. |
| * |
| * Note that SDL will only deal with SIMD instruction sets it is aware of; |
| * for example, SDL 2.0.8 knows that SSE wants 16-byte vectors |
| * (SDL_HasSSE()), and AVX2 wants 32 bytes (SDL_HasAVX2()), but doesn't |
| * know that AVX-512 wants 64. To be clear: if you can't decide to use an |
| * instruction set with an SDL_Has*() function, don't use that instruction |
| * set with memory allocated through here. |
| * |
| * SDL_AllocSIMD(0) will return a non-NULL pointer, assuming the system isn't |
| * out of memory. |
| * |
| * \param len The length, in bytes, of the block to allocated. The actual |
| * allocated block might be larger due to padding, etc. |
| * \return Pointer to newly-allocated block, NULL if out of memory. |
| * |
| * \sa SDL_SIMDAlignment |
| * \sa SDL_SIMDFree |
| */ |
| extern void * SDL_SIMDAlloc(const size_t len); |
| |
| /** |
| * \brief Deallocate memory obtained from SDL_SIMDAlloc |
| * |
| * It is not valid to use this function on a pointer from anything but |
| * SDL_SIMDAlloc(). It can't be used on pointers from malloc, realloc, |
| * SDL_malloc, memalign, new[], etc. |
| * |
| * However, SDL_SIMDFree(NULL) is a legal no-op. |
| * |
| * \sa SDL_SIMDAlloc |
| */ |
| extern void SDL_SIMDFree(void *ptr); |
| |
| /* vi: set ts=4 sw=4 expandtab: */ |
| |