[FFmpeg-devel] [PATCH] simplify GET_UTF8 to use ff_log2_tab

Vitor Sessak vitor1001
Thu Dec 13 22:51:04 CET 2007


Hi

Andreas ?man wrote:
> M?ns Rullg?rd wrote:
>> What the hell is wrong with that architecture?  On ARM, the CLZ (count
>> leading zeros) instruction takes all of ONE cycle.  I believe MIPS is
>> similar.
> 
> Yes, same on PPC. At least it's O(1)

Just wondering, does gcc's __builtin_clz() do what it supposed to do in 
those architectures? Is there any change that using it in av_log2 would 
speed anything up?

-Vitor




More information about the ffmpeg-devel mailing list