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Re: [RFC] Enabling loop unrolls at -O3?

On 11/5/05, Giovanni Bajo <rasky@develer.com> wrote:
> Steven Bosscher <stevenb@suse.de> wrote:
>
> >> I guess the issue is what does "huge" mean, it is hard to discuss based
> >> on loaded adjectives taking the place of data :-)
> >
> > Huge here means 15-20% on x86* hosts.
>
> I don't consider this huge for -O3. I think -O3 can be slower if it achieves
> better code, and -funroll-loops makes it do just that.

First of all, this is too late for 4.1, second, we enable loop-unrolling with
FDO.  And without FDO, -funroll-loops is not necessarily an improvement.

Richard.
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