On 7/25/06, Anton Luht <[EMAIL PROTECTED]> wrote:
Hello, I'd like to suggest people that know some algorithmic tricks to look at the corresponding areas of classlib. Maybe some of the community members had (un)lucky experience of tuning performance of some application that led them to a deep knowledge of some very specific area has good approaches but not too widely known to an average developer. It might also be an interest for students and other people from institutes and universities. What I'm talking about is not related to 'premature optimization' that is now being discussed in another thread but something very narrow, limited to maybe one method and not influencing anything else. For example, consider current implementation of java.util.BitSet.cardinality() . It just checks all bits one by one and increments count. [1] Gives an overview of algorithms for checking set bit count. The fastest algorithms are with table lookup, which requires additional memory, but there are algorithms that are several times faster than iteration (in C) and don't require tables.
+1. I believe
such local optimizations with good comments and links to corresponding resources won't do any harm and are a good point to start with. Does it make sence?
Yes. But I don't think it's time to shift too much efforts to this area now. As you mentioned above, we are glad to see if anyone volunteers to do such kind of things. I also suggest to focus on proper codes, which are hot or core. Never waste time on seldom executed codes. :) Thanks. [1] http://www-db.stanford.edu/~manku/bitcount/bitcount.html
-- Regards, Anton Luht, Intel Middleware Products Division --------------------------------------------------------------------- Terms of use : http://incubator.apache.org/harmony/mailing.html To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
-- Andrew Zhang China Software Development Lab, IBM
