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Re: AutoFDO profile toolchain is open-sourced


On Fri, Apr 10, 2015 at 3:43 PM, Jan Hubicka <hubicka@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


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