From 8728ce4448abf2d41beec8df71625f3dd02e3593 Mon Sep 17 00:00:00 2001 From: Sam Lantinga Date: Sat, 8 Jun 2019 14:54:37 -0700 Subject: [PATCH] Fixed bug 4557 - SDL_SIMDAlloc and *Free should be in the public interface Martin Gerhardy These functions are really useful and should get exposed imo. --- include/SDL_cpuinfo.h | 63 ++++++++++++++++++++++ src/cpuinfo/SDL_cpuinfo.c | 1 - src/cpuinfo/SDL_simd.h | 88 ------------------------------- src/dynapi/SDL_dynapi_overrides.h | 3 ++ src/dynapi/SDL_dynapi_procs.h | 3 ++ src/video/SDL_RLEaccel.c | 1 - src/video/SDL_surface.c | 1 - 7 files changed, 69 insertions(+), 91 deletions(-) delete mode 100644 src/cpuinfo/SDL_simd.h diff --git a/include/SDL_cpuinfo.h b/include/SDL_cpuinfo.h index 07ac196c0..1e12d7e24 100644 --- a/include/SDL_cpuinfo.h +++ b/include/SDL_cpuinfo.h @@ -196,6 +196,69 @@ extern DECLSPEC SDL_bool SDLCALL SDL_HasNEON(void); */ extern DECLSPEC int SDLCALL SDL_GetSystemRAM(void); +/** + * \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 DECLSPEC size_t SDLCALL 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 DECLSPEC void * SDLCALL 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 DECLSPEC void SDLCALL SDL_SIMDFree(void *ptr); + +/* vi: set ts=4 sw=4 expandtab: */ /* Ends C function definitions when using C++ */ #ifdef __cplusplus } diff --git a/src/cpuinfo/SDL_cpuinfo.c b/src/cpuinfo/SDL_cpuinfo.c index 7c050940b..c4dd6633c 100644 --- a/src/cpuinfo/SDL_cpuinfo.c +++ b/src/cpuinfo/SDL_cpuinfo.c @@ -22,7 +22,6 @@ #include "SDL_config.h" #else #include "../SDL_internal.h" -#include "SDL_simd.h" #endif #if defined(__WIN32__) || defined(__WINRT__) diff --git a/src/cpuinfo/SDL_simd.h b/src/cpuinfo/SDL_simd.h deleted file mode 100644 index 1def3d57b..000000000 --- a/src/cpuinfo/SDL_simd.h +++ /dev/null @@ -1,88 +0,0 @@ -/* - Simple DirectMedia Layer - Copyright (C) 1997-2019 Sam Lantinga - - 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: */ - diff --git a/src/dynapi/SDL_dynapi_overrides.h b/src/dynapi/SDL_dynapi_overrides.h index 25835246c..5a604e888 100644 --- a/src/dynapi/SDL_dynapi_overrides.h +++ b/src/dynapi/SDL_dynapi_overrides.h @@ -714,3 +714,6 @@ #define SDL_RenderCopyExF SDL_RenderCopyExF_REAL #define SDL_GetTouchDeviceType SDL_GetTouchDeviceType_REAL #define SDL_UIKitRunApp SDL_UIKitRunApp_REAL +#define SDL_SIMDGetAlignment SDL_SIMDGetAlignment_REAL +#define SDL_SIMDAlloc SDL_SIMDAlloc_REAL +#define SDL_SIMDFree SDL_SIMDFree_REAL diff --git a/src/dynapi/SDL_dynapi_procs.h b/src/dynapi/SDL_dynapi_procs.h index 3bf0a45ce..bab4c2904 100644 --- a/src/dynapi/SDL_dynapi_procs.h +++ b/src/dynapi/SDL_dynapi_procs.h @@ -770,3 +770,6 @@ SDL_DYNAPI_PROC(SDL_TouchDeviceType,SDL_GetTouchDeviceType,(SDL_TouchID a),(a),r #ifdef __IPHONEOS__ SDL_DYNAPI_PROC(int,SDL_UIKitRunApp,(int a, char *b, SDL_main_func c),(a,b,c),return) #endif +SDL_DYNAPI_PROC(size_t,SDL_SIMDGetAlignment,(void),(),return) +SDL_DYNAPI_PROC(void*,SDL_SIMDAlloc,(const size_t a),(a),return) +SDL_DYNAPI_PROC(void,SDL_SIMDFree,(void *a),(a),) diff --git a/src/video/SDL_RLEaccel.c b/src/video/SDL_RLEaccel.c index e105091cf..b5aaf4d5a 100644 --- a/src/video/SDL_RLEaccel.c +++ b/src/video/SDL_RLEaccel.c @@ -89,7 +89,6 @@ #include "SDL_sysvideo.h" #include "SDL_blit.h" #include "SDL_RLEaccel_c.h" -#include "../cpuinfo/SDL_simd.h" #ifndef MIN #define MIN(a, b) ((a) < (b) ? (a) : (b)) diff --git a/src/video/SDL_surface.c b/src/video/SDL_surface.c index c0cc22187..75dc2bb26 100644 --- a/src/video/SDL_surface.c +++ b/src/video/SDL_surface.c @@ -26,7 +26,6 @@ #include "SDL_RLEaccel_c.h" #include "SDL_pixels_c.h" #include "SDL_yuv_c.h" -#include "../cpuinfo/SDL_simd.h" /* Check to make sure we can safely check multiplication of surface w and pitch and it won't overflow size_t */