Re: bit_ffs
"Ruud H.G. van Tol" <[email protected]>
| Newsgroups | gmane.comp.mathematics.pari.devel |
|---|---|
| Message-ID | <[email protected]> |
On 2023-03-30 19:43, Ruud H.G. van Tol wrote: > 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 ) Similar: bit_cts(n) = logint( bitand( bitneg(n), n + 1 ), 2 ) -- Ruud