New UTF-8 stride function

[Dmitry Olshansky]

27-May-2013 23:21, Martin Nowak пишет:
>
> On 05/26/2013 10:49 PM, Dmitry Olshansky wrote:
>  > If there is anything that come out of UTF-8 discussion is that I decided
>  > to dust off my experimental implementation of UTF-8 stride function.
>  > Just for fun.
>  >
>  > The key difference vs std is in handling non-ASCII case.
>  > I'm replacing bsr intrinsic with a what I call an "in-register lookup
>  > table" (neat stuff that is a piece of cake, thx to CTFE).
>  >
>  > See unittest/benchmark here:
>  > https://gist.github.com/blackwhale/5653927
>  >
> Looks promising.

Cool, I'm not alone in this :)

The only definitive results so far is that it takes less cycles on 32 
bit. For me AMD CodeAnalyst confirms this is literally in cycles of up 
to 33% less with smaller samples in a loop. ASCII-only case seems to 
stay more or less the same (at least cycle-wise but not in time...) 
saving my sanity.

>
> These are huge and most likely the performance is limited by the memory
> bandwith.
>

That could be it. I'll be making measurement on smaller samples of said 
files and spin on them. More tests to come tomorrow.


-- 
Dmitry Olshansky