On Sat, Jan 7, 2017 at 7:45 PM, Jim Nasby <jim.na...@bluetreble.com> wrote: > Well, now that there's 3 places that need to do almost the same thing, I > think it'd be best to just centralize this somewhere. I realize that's not > going to save any significant amount of code, but it would make it crystal > clear what's going on (assuming the excellent comment above RIGHTMOST_ONE > was kept).
Hmm. This sounds a lot like what fls() and my_log2() also do. I've been quietly advocating for fls() because we only provide an implementation in src/port if the operating system doesn't have it, and the operating system may have an implementation that optimizes to a single machine-language instruction (bsrl on x86, I think, see 4f658dc851a73fc309a61be2503c29ed78a1592e). But the fact that our src/port implementation uses a loop instead of the RIGHTMOST_ONE() trick seems non-optimal. -- 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
