On Fri, Jul 31, 2020 at 1:00 PM Andres Freund <and...@anarazel.de> wrote: > > Perhaps we could add a comment about this, e.g. > > Marking these pointers with pg_restrict tells the compiler that str > > and str->data can't overlap, which may allow the compiler to optimize > > better when this code is inlined. For example, it may be possible to > > keep str->data in a register across consecutive appendStringInfoString > > operations. > > > > Since pg_restrict is not widely used, I think it's worth adding this > > kind of annotation, lest other hackers get confused. I'm probably not > > the only one who isn't on top of this. > > Would it make more sense to have a bit of an explanation at > pg_restrict's definition, instead of having it at (eventually) multiple > places?
I think, at least for the first few, it might be better to have a more specific explanation at the point of use, as it may be easier to understand in specific cases than in general. I imagine this only really makes sense for places that are pretty hot. > Ah, I misunderstood. Yea, there's no reason not to do that. OK, then I vote for that version, as I think it looks nicer. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
