[Ffmpeg-devel] [RFC] smallcpy for h264

Siarhei Siamashka siarhei.siamashka
Sat Oct 7 13:35:18 CEST 2006


On Saturday 07 October 2006 14:21, Michael Niedermayer wrote:

> On Sat, Oct 07, 2006 at 04:11:28AM +0200, Luca Barbato wrote:
> > here a pretty dumb patch that happens to work nicely on my system,
> > probably a better solution should be avoding memcpy.
>
> gcc on x86 replaces memcpy(constant) by inlined and fast code IIRC so
> anything like the proposed patch needs to be very carefully benchmarked
> on x86

Also that's one of the reasons why blindly using
#define memcpy(a, b, c) fastmemcpy(a, b, c)
is not very desirable and more control over memory block copy 
implementation that gets used for different purposes (small constant size
block copy, aligned block copy, large block copy, etc.) would be good to have.

After all, it is easy to define all these memory copy cases to the plain
memcpy by default, so it should not have any negative impact.




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