Mercurial > sdl-ios-xcode
view include/SDL_cpuinfo.h @ 3899:081aecdb0911 SDL-1.2
From: Gabriel Gambetta
To: SDL Mailing List <sdl@libsdl.org>
Date: Fri, 17 Nov 2006 00:39:29 -0200
Subject: [SDL] Alpha blending bug - fixed?
It turns out mm5 never got the correct value. This failed :
[...]
"movd %1, %%mm5\n\t"
: : "m" (amask), "m" (sf->Ashift) );
mm5 got 0xFF000018 instead of 0x00000018. However I did this :
Uint32 ashift = sf->Ashift;
[...]
"movd %1, %%mm5\n\t"
: : "m" (amask), "m" (ashift) );
and everything worked fine.
The only thing I could find out was that ashift is 32-bit aligned but
sf->Ashift isn't:
printf("ashift %8X [%d]\n", &ashift, (int)(&ashift) % 4);
printf("sf->Ashift %8X [%d]\n", &sf->Ashift, (int)(&sf->Ashift) % 4);
ashift at BFF0E0C4 [0]
sf->Ashift at 08AFB9CD [1]
Could this be the problem? If it is, the fix is extremely trivial.
Should I submit a patch?
--Gabriel
author | Ryan C. Gordon <icculus@icculus.org> |
---|---|
date | Tue, 21 Nov 2006 23:17:00 +0000 |
parents | ef9a9064bff2 |
children | 782fd950bd46 c121d94672cb a1b03ba2fcd0 |
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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 */ /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* CPU feature detection for SDL */ #ifndef _SDL_cpuinfo_h #define _SDL_cpuinfo_h #include "SDL_stdinc.h" #include "begin_code.h" /* Set up for C function definitions, even when using C++ */ #ifdef __cplusplus extern "C" { #endif /* This function returns true if the CPU has the RDTSC instruction */ extern DECLSPEC SDL_bool SDLCALL SDL_HasRDTSC(void); /* This function returns true if the CPU has MMX features */ extern DECLSPEC SDL_bool SDLCALL SDL_HasMMX(void); /* This function returns true if the CPU has MMX Ext. features */ extern DECLSPEC SDL_bool SDLCALL SDL_HasMMXExt(void); /* This function returns true if the CPU has 3DNow features */ extern DECLSPEC SDL_bool SDLCALL SDL_Has3DNow(void); /* This function returns true if the CPU has 3DNow! Ext. features */ extern DECLSPEC SDL_bool SDLCALL SDL_Has3DNowExt(void); /* This function returns true if the CPU has SSE features */ extern DECLSPEC SDL_bool SDLCALL SDL_HasSSE(void); /* This function returns true if the CPU has SSE2 features */ extern DECLSPEC SDL_bool SDLCALL SDL_HasSSE2(void); /* This function returns true if the CPU has AltiVec features */ extern DECLSPEC SDL_bool SDLCALL SDL_HasAltiVec(void); /* Ends C function definitions when using C++ */ #ifdef __cplusplus } #endif #include "close_code.h" #endif /* _SDL_cpuinfo_h */