[Ffmpeg-devel] PATCH Blackfin UNALIGNED_STORES_ARE_BAD in bitstream.h

[Michael Niedermayer]

Hi

On Tue, Apr 17, 2007 at 11:56:14AM -0400, Rich Felker wrote:
> On Tue, Apr 17, 2007 at 05:39:35PM +0200, Michael Niedermayer wrote:
> > > Index: bitstream.h
> > > ===================================================================
> > > --- bitstream.h	(revision 8596)
> > > +++ bitstream.h	(working copy)
> > > @@ -166,7 +166,7 @@
> > >      uint8_t run;
> > >  } RL_VLC_ELEM;
> > >  
> > > -#if defined(ARCH_SPARC) || defined(ARCH_ARMV4L) || defined(ARCH_MIPS)
> > > +#if defined(ARCH_SPARC) || defined(ARCH_ARMV4L) || defined(ARCH_MIPS) || defined(ARCH_BFIN)
> > >  #define UNALIGNED_STORES_ARE_BAD
> > 
> > looks ok
> 
> IMO we should turn this the other way around:
> 
> #if !defined(ARCH_X86) && !defined(...)
> 
> Then the code will ALWAYS work, and just be suboptimal on archs we
> haven't identified yet, rather than crashing on unknown archs.

i strongly object to this, noone would ever add any architecture besides x86
to it, how should anyone even know of this line?
there are simlar other things in the code like several differnt bitreaders
noone after _years_ has benchmarked them on non x86 with very few exceptions

if it crashes and the person sends a bugrport its trivial to add the arch
if its just slower than what it could be nothing will happen it will always
stay slow

if configure would print a big warning like
WARINING: configure doesnt know your architecture and so has disabled all
optimizations, please try the following switches: ... and report bechmarks
to ffmpeg-dev so we can automate the optimization selection

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Breaking DRM is a little like attempting to break through a door even
though the window is wide open and the only thing in the house is a bunch
of things you dont want and which you would get tomorrow for free anyway
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