Am 05 Sep 2001 21:34:21 +0200 schrieb Sven Neumann:

> > Okay, so you work on 2 pixels concurrently by using corresping masks.
> read the code (and my mail) again. I'm not doing operations on 2 pixels.
> The code is combining the multiplications done on 2 channels of the 
> same pixel into one. Also it is also meant as an example of what can 
> be done without using CPU-specific instructions.

Of course I meant channels instead pixels... However for simple
mainpulations the shifting and masking is much more work than simply
operating on one channel at once, especially since those simple
operations have a much higher chance to be scheduled into different
units in the CPU (superscalar processing is quite common) than code
where you have a lot of depencies. So even if this approach would result
in less instructions it probably might run slower.


Gimp-developer mailing list

Reply via email to