[Bug middle-end/40029] [4.5 Regression] Big degradation on swim/mgrid on powerpc 32/64 after alias improvement merge (gcc r145494)

[rguenther at suse dot de]

------- Comment #6 from rguenther at suse dot de  2009-05-29 20:15 -------
Subject: Re:  [4.5 Regression] Big degradation on
 swim/mgrid on powerpc 32/64 after alias improvement merge (gcc r145494)

On Fri, 29 May 2009, luisgpm at linux dot vnet dot ibm dot com wrote:

> ------- Comment #5 from luisgpm at linux dot vnet dot ibm dot com  2009-05-29 19:52 -------
> From predictive commoning we gain a bit more performance, probably due to the
> bigger unrolling factor.
> 
> Any chance of the unrolling taking place while still using PRE?

-funroll[-all]-loops doesn't seem to do the job.  I didn't check if
enabling sms would do it.  Other unrolling on the tree level is only
implemented as side-effect of other optimizations (like vectorization
or predictive commoning or prefetching) :/

Richard.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40029