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Re: Remove NOTE_INSN_PREDICTION


On Wednesday 21 July 2004 19:09, Jan Hubicka wrote:
> > Hi,
> >
> > NOTE_INSN_PREDICTION was only still used for return predictions,
> > which are broken since the patch to unify return statements for
> > lower GIMPLE.  So we spend a lot of time (computing DOM and PDOM)
> > in predict.c only to predict a single return with a very poor and
> > broken prediction.
> >
> > With this patch, we no longer predict returns like this.  I will
> > reimplement this in the tree branch prediction code instead.
> >
> > Bootstrapped on i686-suse-linux-gnu, testing ongoing.  OK when it
> > passes?
>
> Yes, this is OK.

Thanks.


>  I intended to propose this once we do have replacement
> for this logic (via branch prediction on trees), but there is no need
> to keep broken feature around anyway.  Tree profiling already replace
> most of the logic, I just need to find time to do the merge.

You already merged the return predictors.  They're also broken
because we only have one RETURN_EXPR on GIMPLE.  But at least
we can fix those, whereas these RTL predictors are broken beyond
repair.


> Please remove also the unused predictors from predict.def.

Can't do, they're still used ;-)

Gr.
Steven




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