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

HERMES 1.2.4 (c)1998 Christian Nentwich (brn) (c.nentwich@cs.ucl.ac.uk)
and quite a few assembler routines (c) Glenn Fielder (gaffer@gaffer.org)

This library and all the files enclosed in this package are free software
under the terms of the GNU Library General Public License (LGPL). Please
refer to the included file COPYING.LIB for the exact terms.
----------------------------------------------------------------------------

This is a stripped down version of HERMES, including only the x86 assembler
converters, for use with Simple DirectMedia Layer.

The full HERMES library is available at:  http://hermes.terminal.at/