On Tue, Oct 8, 2013 at 2:28 PM, Asumu Takikawa <[email protected]> wrote: > On 2013-10-04 14:03:00 -0400, Jon Zeppieri wrote: >> The HAMT library I began working on at the RacketCon Hackathon is now >> available at [https://github.com/97jaz/hamt]. Suggestions are welcome. > > Very nice! Have you tried using the version of `popcount` in the `data` > library's private interface to see if that's any faster? > > https://github.com/plt/racket/blob/master/racket/collects/data/private/count-bits-in-fixnum.rkt >
I have not (since I didn't know it existed), but I would be surprised if it were faster. My version trades off space for time by building, in advance, a vector of popcounts for all 16-bit integers, and it's is specialized to work on numbers up to 32 bits rather than on all fixnums. I think it's worthwhile, though, to find out if there is any measurable performance difference, since it would be nice not to need a 65536-length vector hanging around. -Jon ____________________ Racket Users list: http://lists.racket-lang.org/users
