Mercurial > sdl-ios-xcode
diff src/video/SDL_memops.h @ 0:74212992fb08
Initial revision
author | Sam Lantinga <slouken@lokigames.com> |
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date | Thu, 26 Apr 2001 16:45:43 +0000 |
parents | |
children | cf2af46e9e2a |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/video/SDL_memops.h Thu Apr 26 16:45:43 2001 +0000 @@ -0,0 +1,127 @@ +/* + SDL - Simple DirectMedia Layer + Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public + License as published by the Free Software Foundation; either + version 2 of the License, or (at your option) any later version. + + This library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with this library; if not, write to the Free + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + + Sam Lantinga + slouken@devolution.com +*/ + +#ifdef SAVE_RCSID +static char rcsid = + "@(#) $Id$"; +#endif + +#ifndef _SDL_memops_h +#define _SDL_memops_h + +/* System dependent optimized memory manipulation routines: +*/ +#include <string.h> + +#if defined(__GNUC__) && defined(i386) +/* Thanks to Brennan "Bas" Underwood, for the inspiration. :) + */ +#define SDL_memcpy(dst, src, len) \ +do { \ + int u0, u1, u2; \ + __asm__ __volatile__ ( \ + "cld\n\t" \ + "rep ; movsl\n\t" \ + "testb $2,%b4\n\t" \ + "je 1f\n\t" \ + "movsw\n" \ + "1:\ttestb $1,%b4\n\t" \ + "je 2f\n\t" \ + "movsb\n" \ + "2:" \ + : "=&c" (u0), "=&D" (u1), "=&S" (u2) \ + : "0" ((unsigned)(len)/4), "q" (len), "1" (dst),"2" (src) \ + : "memory" ); \ +} while(0) + +#define SDL_revcpy(dst, src, len) \ +do { \ + int u0, u1, u2; \ + char *dstp = (char *)(dst); \ + char *srcp = (char *)(src); \ + int n = (len); \ + if ( n >= 4 ) { \ + __asm__ __volatile__ ( \ + "std\n\t" \ + "rep ; movsl\n\t" \ + : "=&c" (u0), "=&D" (u1), "=&S" (u2) \ + : "0" (n >> 2), \ + "1" (dstp+(n-4)), "2" (srcp+(n-4)) \ + : "memory" ); \ + } \ + switch (n & 3) { \ + case 3: dstp[2] = srcp[2]; \ + case 2: dstp[1] = srcp[1]; \ + case 1: dstp[0] = srcp[0]; \ + break; \ + default: \ + break; \ + } \ +} while(0) + +#define SDL_memmove(dst, src, len) \ +do { \ + if ( (dst) < (src) ) { \ + SDL_memcpy((dst), (src), (len)); \ + } else { \ + SDL_revcpy((dst), (src), (len)); \ + } \ +} while(0) + +#define SDL_memset4(dst, val, len) \ +do { \ + int u0, u1, u2; \ + __asm__ __volatile__ ( \ + "cld\n\t" \ + "rep ; stosl\n\t" \ + : "=&D" (u0), "=&a" (u1), "=&c" (u2) \ + : "0" (dst), "1" (val), "2" ((Uint32)(len)) \ + : "memory" ); \ +} while(0) + +#endif /* GNU C and x86 */ + +/* If there are no optimized versions, define the normal versions */ +#ifndef SDL_memcpy +#define SDL_memcpy(dst, src, len) memcpy(dst, src, len) +#endif +#ifndef SDL_revcpy +#define SDL_revcpy(dst, src, len) memmove(dst, src, len) +#endif +#ifndef SDL_memset4 +#define SDL_memset4(dst, val, len) \ +do { \ + unsigned _count = (len); \ + unsigned _n = (_count + 3) / 4; \ + Uint32 *_p = (Uint32 *)(dst); \ + Uint32 _val = (val); \ + switch (_count % 4) { \ + case 0: do { *_p++ = _val; \ + case 3: *_p++ = _val; \ + case 2: *_p++ = _val; \ + case 1: *_p++ = _val; \ + } while ( --_n ); \ + } \ +} while(0) +#endif + +#endif /* _SDL_memops_h */