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Re: Incorrect application of loop exit heuristic?
- From: Pat Haugen <pthaugen at us dot ibm dot com>
- To: Jan Hubicka <hubicka at ucw dot cz>
- Cc: gcc at gcc dot gnu dot org
- Date: Mon, 21 Aug 2006 13:22:25 -0500
- Subject: Re: Incorrect application of loop exit heuristic?
Jan Hubicka <email@example.com> wrote on 08/19/2006 07:51:42 PM:
> > Hi,
> > thepatch limiting minimal probability to 2% seems to make sense to me,
> > so please submit it for review. It would be nice to have the code to
> > compute maximal number of exits from loop too, but if it is really 9,
> > would end up with 1% (it might however make difference elsewhere).
> > If you would feed motivated to do so, please just do ;) Otheriwse I
> > add it to my ever growing TODO list.
> this patch at least hides the ugly details within some abstraction so we
> can eventally go for propagating reliability information across CFG if
> we conclude it is important. How does it work for you?
I like your approach, thanks. I've confirmed that the generated code no
longer contains the mis-predicted branch hints. Will follow up with
results from SPEC run once I get them (hosed things up for myself, so
restarting from scratch) :-(