On Mon, Jul 23, 2012 at 12:07 PM, Peter Geoghegan <pe...@2ndquadrant.com> wrote: > On 23 July 2012 16:36, Robert Haas <robertmh...@gmail.com> wrote: >> On Mon, Jul 23, 2012 at 11:34 AM, Peter Geoghegan <pe...@2ndquadrant.com> >> wrote: >>>> tss->buflen = 1 << ffs(len1); >>> >>> I'm sorry, I don't follow you here. What is ffs() ? >> >> Sorry, fls, not ffs. I always get those mixed up. >> >> See src/port/fls.c > > Oh, okay. Since, I infer, we're starting from a buffer-size that's a > power-of-two anyway, is there really any advantage in doing this > rather than just doubling the buffer size each time?
Well, if you're using a builtin fls rather than our src/port implementation, it's probably a single machine language instruction instead of a loop. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
