[Ffmpeg-devel] VP3/Theora Perfection

[Mike Melanson]

Michael Niedermayer wrote:
> hmm, ill try explain it again, no doubt my first try is a little strangely 
> written
> 
> my dev tree got slower after a cvs up, i dont have the benchmark scores any 
> more, and my dev tree changed since then so i cant rerun it easily
> 
> testing the r1.57 -> r1.58 change on a clean tree shows that the new version 
> is faster (see my first benchmark) but if -finline-limit=2000 is added then 
> r1.57 is faster (see my second benchmark), its also faster then r1.58 without 
> -finline-limit=2000

Patient: "Doctor! It hurts when I do this."
Doctor: "So don't do that."

:) I'm confused (big surprise). The new code is faster with the standard 
compilation line. So you used a non-standard compilation line to make 
the new code slower?

> the new code is also significantly smaller then the old as it replaces a 
> "large" switch with look up tables
> 
> from all that evidence i conclude that gcc didnt inline unpack_token() or 
> unpack_vlcs() orginally and that the speed increase seen on a clean tree is 
> not because the function is really faster but because it is inlined

	I think I understand. I will make some tests along these lines...
-- 
	-Mike Melanson