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Re: [Patch] Do not rerun loop optimisation by default.
Richard Henderson wrote:
> On Wed, Sep 19, 2001 at 12:10:16AM +0200, Toon Moene wrote:
> > The way you formulate this proposal suggests that you have an algorithm
> > for constructing "synthetic GIVs that are the optimal base address for
> > the DEST_ADDR GIVs".
> >
> > How would you do that ?
>
> I havn't thought it out completely, but,
>
> If you find a DEST_ADDR giv that does more than (reg + offset),
> then you create new DEST_REG givs for each sub operation. The
> benefit of the new givs would be zero, so we wouldn't reduce
> them unless they combined with something else.
Ah, OK, so it wouldn't work (optimally) when -freduce-all-givs is in
effect, because that would bypass benefit considerations ...
--
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