[U-Boot] [PATCH V2 1/3] memcpy: copy one word at a time if possible

Alessandro Rubini rubini at unipv.it
Thu Oct 8 18:00:26 CEST 2009


> No interest in the suggestion to not require count to be an exact
> multiple of 4/8?

Actually, I wrote about that in my patch 0/3.

> I don't think it would be that hard to update the logic accordingly
> and this would let your code be utilized much more often, especially
> if/when we run on a 64-bit machine.

That's true, but I think the most important case is lcd scrolling,
where it's usually a big power of two -- that's where we had the #ifdef,
so the problem was known, I suppose.

Currently, I don't even know if this is going to be picked up, so I
don't want to go too far -- and in that case I would like to measure
things and be able to test for stupid bugs, so it takes time.
Scrolling the video is an easy test for memcpy.

If there's interest, there's memmov to fix; it's used pretty often and
it's the same idea as memcpy (well, scrolling should use memmove,
in theory).

/alessandro


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