[RFC] Improve Tree-SSA if-conversion - convergence of efforts

[Tehila Meyzels]

Michael Matz <matz@suse.de> wrote on 31/07/2007 18:05:53:

> Hi,
>
> On Tue, 31 Jul 2007, Daniel Berlin wrote:
>
> > > 2. Store-sinking/load hoisting may have an overhead and may degrade
> > > performance unless the relevant conditional branch gets if-converted.
> >
> > I agree with you for conditional stores/loads.
> >
> > The unconditional store/load stuff, however, is exactly what
> > tree-ssa-sink was meant to do, and belongs there (this is #3 above).
I'm
> > certainly going to fight tooth and nail against trying to shoehorn
> > unconditional store sinking into if-conv.
>
> FWIW I also agree that handling unconditional stores/loads does not
belong
> in if-conv (or phi-opt), but in ssa-sink (or some similar transformation
> which can or can not use value numbers and the like).

OK.
And what's your opinion WRT conditional loads/stores?
Since you've sent your conditional store transformation patch,
I guess the meaning could be rewriting it on the top of tree-if-conv.

Tehila.

>
>
> Ciao,
> Michael.