Mercurial > sdl-ios-xcode
view src/timer/mint/SDL_vbltimer.S @ 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 | c9b51268668f |
| children | eb5e61b72da3 |
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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 */ /* * VBL queue routine * * Patrice Mandin */ #define _vbl_queue 0x456 .text .globl _SDL_AtariVblInstall .globl _SDL_AtariVblUninstall /*--- Vector installer ---*/ _SDL_AtariVblInstall: movel sp@(4),my_vector lea _my_vbl,a0 clrw vbl_mutex /* Stop interrupts */ movew #0x2700,sr /* Read vbl_queue pointer */ movel _vbl_queue.w,a1 /* Search a free place */ moveq #7,d0 bcl_search_place: movel (a1),d1 beqs place_found addql #4,a1 dbra d0,bcl_search_place /* Not found */ moveq #1,d0 bras exit_vbl_queue /* Then install ourselves */ place_found: movel a0,(a1) moveq #0,d0 exit_vbl_queue: /* Restart interrupts */ movew #0x2300,sr rts /*--- Vector uninstaller ---*/ _SDL_AtariVblUninstall: movel sp@(4),d0 cmpl my_vector,d0 bnes badvector movel #_my_vbl,d0 /* Stop interrupts */ movew #0x2700,sr /* Read vbl_queue pointer */ movel _vbl_queue.w,a1 /* Search where we are */ moveq #7,d1 bcl2_search_place: cmpl (a1),d0 bnes next_place clrl (a1) moveq #0,d1 next_place: addql #4,a1 dbra d1,bcl2_search_place /* Restart interrupts */ movew #0x2300,sr badvector: rts /*--- Our vbl ---*/ _my_vbl: /* Verify if this is not already running */ tstw vbl_mutex bnes vbl_end notw vbl_mutex moveml d0-d7/a0-a6,sp@- movel my_vector,a0 jsr a0@ moveml sp@+,d0-d7/a0-a6 clrw vbl_mutex vbl_end: rts .data .even .comm vbl_mutex,2*1 .even .comm my_vector,4*1