On Fri, Apr 10, 2015 at 3:43 PM, Jan Hubicka <hubi...@ucw.cz> wrote: >> LBR is used for both cfg edge profiling and indirect call Target value >> profiling. > I see, that makes sense ;) I guess if we want to support profile collection > on targets w/o this feature we could still use one of the algorithms that > try to guess edge profile from BB profile.
Our experience with sampling cycles or retired instructions to guess BB profile has not been great -- the profile quality is significantly worse than LBR (which can almost match instrumentation based profile). David > > Honza
