Re: bit_ffs

["Ruud H.G. van Tol" <rvtol@isolution.nl>]

On 2023-03-30 19:02, Ruud H.G. van Tol wrote:
> Might be interesting to add:
>
> https://en.wikipedia.org/wiki/Find_first_set
> https://www.man7.org/linux/man-pages/man3/ffs.3.html
> https://www.go4expert.com/articles/builtin-gcc-functions-builtinclz-t29238/ 
>
>
> Or are those too low-level?
>
> bit_ffs, bit_ctz

Count trailing set bits:

bit_cts(n) = logint( 1 + bitand(n, bitneg(n) - 1), 2 )

(no idea yet if that is a good implementation)

Would also be nice to have a turbo version of that.

-- Ruud