Skip to content
Browse files

Fixed bug 4557 - SDL_SIMDAlloc and *Free should be in the public inte…


Martin Gerhardy

These functions are really useful and should get exposed imo.
  • Loading branch information
slouken committed Jun 8, 2019
1 parent 56b7f4c commit 8728ce4448abf2d41beec8df71625f3dd02e3593
@@ -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
@@ -22,7 +22,6 @@
#include "SDL_config.h"
#include "../SDL_internal.h"
#include "SDL_simd.h"

#if defined(__WIN32__) || defined(__WINRT__)

This file was deleted.

@@ -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
@@ -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)
SDL_DYNAPI_PROC(void*,SDL_SIMDAlloc,(const size_t a),(a),return)
SDL_DYNAPI_PROC(void,SDL_SIMDFree,(void *a),(a),)
@@ -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))
@@ -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 */

0 comments on commit 8728ce4

Please sign in to comment.