Fixed bug #15 SDL_blit_A.mmx-speed.patch.txt -- Speed improvements and a bugfix for the current GCC inline mmx asm code: - Changed some ops and removed some resulting useless ones. - Added some instruction parallelism (some gain) The resulting speed on my Xeon improved upto 35% depending on the function (measured in fps). - Fixed a bug where BlitRGBtoRGBSurfaceAlphaMMX() was setting the alpha component on the destination surfaces (to opaque-alpha) even when the surface had none. SDL_blit_A.mmx-msvc.patch.txt -- MSVC mmx intrinsics version of the same GCC asm code. MSVC compiler tries to parallelize the code and to avoid register stalls, but does not always do a very good job. Per-surface blending MSVC functions run quite a bit faster than their pure-asm counterparts (upto 55% faster for 16bit ones), but the per-pixel blending runs somewhat slower than asm. - BlitRGBtoRGBSurfaceAlphaMMX and BlitRGBtoRGBPixelAlphaMMX (and all variants) can now also handle formats other than (A)RGB8888. Formats like RGBA8888 and some quite exotic ones are allowed -- like RAGB8888, or actually anything having channels aligned on 8bit boundary and full 8bit alpha (for per-pixel alpha blending). The performance cost of this change is virtually 0 for per-surface alpha blending (no extra ops inside the loop) and a single non-MMX op inside the loop for per-pixel blending. In testing, the per-pixel alpha blending takes a ~2% performance hit, but it still runs much faster than the current code in CVS. If necessary, a separate function with this functionality can be made. This code requires Processor Pack for VC6.

/* File "FastTimes.h" - Original code by Matt Slot <fprefect@ambrosiasw.com>  */
#include "SDL_config.h"
/* Created 4/24/99    - This file is hereby placed in the public domain       */
/* Updated 5/21/99    - Calibrate to VIA, add TBR support, renamed functions  */
/* Updated 10/4/99    - Use AbsoluteToNanoseconds() in case Absolute = double */
/* Updated 2/15/00    - Check for native Time Manager, no need to calibrate   */
/* Updated 3/21/00    - Fixed ns conversion, create 2 different scale factors */
/* Updated 5/03/00    - Added copyright and placed into PD. No code changes   */

/* This file is Copyright (C) Matt Slot, 1999-2000. It is hereby placed into 
   the public domain. The author makes no warranty as to fitness or stability */

#ifndef __FAST_TIMES_HEADER__
#define __FAST_TIMES_HEADER__

/* **** **** **** **** **** **** **** **** **** **** **** **** **** **** **** */
/* **** **** **** **** **** **** **** **** **** **** **** **** **** **** **** */

extern void			FastInitialize(void);
extern UInt64		FastMicroseconds(void);
extern UInt64		FastMilliseconds(void);
extern StringPtr	FastMethod(void);

/* **** **** **** **** **** **** **** **** **** **** **** **** **** **** **** */
/* **** **** **** **** **** **** **** **** **** **** **** **** **** **** **** */

#endif /* __FAST_TIMES_HEADER__ */