Mercurial > sdl-ios-xcode
view src/timer/dc/SDL_systimer.c @ 1542:a8bf1aa21020
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.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Wed, 15 Mar 2006 15:39:29 +0000 |
parents | d910939febfa |
children | 92947e3a18db |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2006 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Sam Lantinga slouken@libsdl.org */ #include "SDL_config.h" #include <kos.h> #include "SDL_thread.h" #include "SDL_timer.h" #include "../SDL_timer_c.h" static unsigned start; /* jif = ms * HZ /1000 ms = jif * 1000/HZ */ void SDL_StartTicks(void) { /* Set first ticks value */ start = jiffies; } Uint32 SDL_GetTicks(void) { return((jiffies-start)*1000/HZ); } void SDL_Delay(Uint32 ms) { thd_sleep(ms); } /* Data to handle a single periodic alarm */ static int timer_alive = 0; static SDL_Thread *timer = NULL; static int RunTimer(void *unused) { while ( timer_alive ) { if ( SDL_timer_running ) { SDL_ThreadedTimerCheck(); } SDL_Delay(10); } return(0); } /* This is only called if the event thread is not running */ int SDL_SYS_TimerInit(void) { timer_alive = 1; timer = SDL_CreateThread(RunTimer, NULL); if ( timer == NULL ) return(-1); return(SDL_SetTimerThreaded(1)); } void SDL_SYS_TimerQuit(void) { timer_alive = 0; if ( timer ) { SDL_WaitThread(timer, NULL); timer = NULL; } } int SDL_SYS_StartTimer(void) { SDL_SetError("Internal logic error: DC uses threaded timer"); return(-1); } void SDL_SYS_StopTimer(void) { return; }