On Wed, 2008-05-14 at 20:25 +0100, Gregory Stark wrote:
> The Linux kernel does have some macros meant to mark unlikely branches
> (usually assertion failures) but I'm not sure how they work. And Gcc also has
> a few optimizations which are driven by profiling data but I it doesn't sound
> like this is one of them.
GCC's profile-driven optimization can be used to guide decisions about
both branch prediction/likelihood and function inlining. IMHO it is
definitely worth building the infrastructure to get Postgres builds with
profile-driven optimization -- certainly more maintainable and less
arbitrary than builtin_expect() and friends to me.
-Neil
