Re: Linux likely() unlikely() for PostgreSQL - Mailing list pgsql-hackers

On Mon, 1 Jul 2024 at 14:08, Peter Geoghegan <pg@bowt.ie> wrote:
>
> On Sun, Jun 30, 2024 at 11:23 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> >         if (trouble)
> >                 ereport(ERROR, ...);
> >
> > could be interpreted as
> >
> >         if (unlikely(trouble))
> >                 ereport(ERROR, ...);
> >
> > But I surely don't want to make thousands of such changes manually.
> > And it's possible that smart compilers already realize this, using
> > a heuristic that any path that ends in pg_unreachable() must be
> > unlikely.  Is there a way to encourage compilers to believe that?
>
> Isn't that what commit 913ec71d68 did, by adding a call to
> pg_attribute_cold to report?

Yes.

David