[Ffmpeg-devel] [PATCH] Some MMX optimizations for Chinese AVS
Fri Jul 28 20:25:00 CEST 2006
Mike Melanson wrote:
> Search for uses of the existing START_TIMER() and STOP_TIMER() macros in
> the tree. They give you a good all-around picture of how tight pieces of
> code are performing. They will give you useful numbers for your purposes.
Thanks, I already used them. But that's rather what I meant with
benchmarking a whole block and trial and error. What I was looking for was
more like checking for rules. For example, the other code I looked at
before seems to adhere to the rule
"If you use a MMX multiply, make sure you have two other instructions in
the code before you use the result of the multiply."
But I don't know if this is a rule I should stick to or just coincidence.
So I would like either
- a good documentation "performant MMX code for dummies"
or (even better)
- the this-MMX-instruction-stalls-due-to-dependency-on-that-result checker
Echte DSL-Flatrate dauerhaft f?r 0,- Euro*. Nur noch kurze Zeit!
"Feel free" mit GMX DSL: http://www.gmx.net/de/go/dsl
More information about the ffmpeg-devel