[FFmpeg-devel] [PATCH] HAVE_AMD3DNOW

[Michael Niedermayer]

On Tue, Jun 09, 2009 at 04:05:14PM -0400, Pavel Pavlov wrote:
> > -----Original Message-----
> > > 
> > > Well, did you try to use some diff viewer that could 
> > colorize my patch 
> > > so it doesn't look ugly? ;)
> > 
> > your patch is ugly no matter which color
> > 
> 
> Did you try pink??

not explicitly, but as the patch is ugly due to its content and not the
color, no matter which color it stays ugly


[...]
> > > Moreover, I still find it quite difficult to get latest 
> > up-to-date mingw
> > > compiler for win32 with their list of install this, downalod that,
> > > overwite this and modify that instructions. After doing all 
> > that magic I
> > > had doubts that hello world would still compile.
> > 
> > maybe you should write a simple and clean 1-click installer for mingw?
> > 
> > > To fix --disable-3dnow it would be enough no remove 
> > references to _3dnow
> > > functions, but it's not enough for icl, since it can't 
> > compile most of
> > > _3dnow asm code.
> > > Initially, I put ifdef __ICL for all 3dnow code that did 
> > not compile.
> > > Obviuosly, it would never be accepted; so for all _3dnow 
> > code I put #if
> > > HAVE_3DNOW ... #endif which is much better. There is no 
> > other way to fix
> > > compilation with current icl.
> > > And the last point... most of win32 developers can't 
> > contribute much -
> > > most of them who use ffmpeg have some version of ffmepeg 
> > dll's and don't
> > > bother with source code which is quite useless on win32, unless they
> > > took extra effort to setup build environment for ffmpeg (which is
> > > overkill for most of the projects that use like 1% functionality
> > > available in ffmpeg)
> > > 
> > > > 
> > > > If OTOH you want to fix --disable-3dnow, that may be welcome 
> > > > though i obviously would prefer this to be done as clean as 
> > > > possible. I dont know what is cleanest but simply not 
> > > > referencing 3dnow functions and letting the compiler remove 
> > > > them seems like an obvious try
> > > > 
> > > > Also, even with iccw 3dnow should be supported not just 
> > > > disabled your patch is not a clean fix for this ...
> > > 
> > > I have no idea what iccw is, I'm talking about icl, which is intel's
> > > compiler for win32.
> > 
> > iccw was my abbreviation for intels c compiler for windows, it seemsed
> > to make sense and given intels compiler on linux does not 
> > have that bug
> > i felt a w for windows should be somewhere in there  but of course
> > we can call it anything you like
> > 
> 
> Well, I call it exactly as it's called. Icl
> Intel compiler doesn't come as a standalone toolset without any
> dependencies. It needs ms compiler on windows and gcc toolset on linux.
> As far as I know it doesn't have it's onwn c/c++ std lib, it's only a
> tool that converts c/c++ code to object files and then it uses host
> compiler libs and tools to create final executables. On linux it uses
> gnu assembler to handle inline asm and that's why it works as is on
> linux. On win32 masm asm is used, so they wrote builtin assembler to
> handle att asm. And that's why it's so contastrained: no lables, no
> direct symbol references, some instructions aren't implemented etc.

i doubt masm lacks 3dnow support


> 
> > anyway, as said fixing --disable-3dnow is welcome if clean 
> > (your patch is
> > not)
> > and making ffmpeg compileable on intels c compiler for 
> > windows first needs
> > an explanation of which instructions why do not compile. Once 
> > we are past
> > that we can discuss which solution (like disabling all asm) 
> > is appropriate
> >
> 
> Disabling all asm is not appropriate solution.

neither is disabling all 3dnow


> See my previous thread: [BUG] : reading memory past the end of the
> buffer
> At some point we started to get crashes (on some pc's/cameras only) with
> code that worked for years and I decided to compile ffmpeg in my spare
> time with icl to be able to debug the problem. It's not importat why and
> what was crashing, the point is that it would never crash if asm
> optimisations were disabled.

> So, it would be nice to have a complete ffmpeg built with all
> optimizations enabled. 

but thats not what your patch does ...

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

While the State exists there can be no freedom; when there is freedom there
will be no State. -- Vladimir Lenin
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