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Re: [rtl-optimization] Improve Data Prefetch for IA-64


On Apr 05, 2005 11:55 AM, Zdenek Dvorak <rakdver@atrey.karlin.mff.cuni.cz> wrote:

> > (IMHO the current RTL IV analysis is not very nice to work
> > with, we could look into improving that first...)
> 
> what problems do you have concretely in mind?

It is hard to find and iterate over all IVs (including GIVs).  For
example the "old new" IV handling, that you had on the rtlopt branch
and what loop-prefetch.c is built on, looked much more convenient.

> > On the other hand, we may not even need it if the RTL unroller
> > will be replaced by the tree one.  I don't know what Zdenek's
> > plans are about that, or if this is a wise thing to do at all.
> 
> I don't think it is the case; as far as I know, it is recommended
> to do non-specific unrolling just before or during scheduling.
> (By "non-specific" I mean unrolling the loops without any other
> reason other than just getting them unrolled).  

Right, that is what I was thinking too.  So that means we have to
improve the new unroller to get it to do what Canqun needs...

Gr.
Steven


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