[patch] enabling vectorization by default at -O3

Vladimir Makarov vmakarov@redhat.com
Thu Sep 13 22:54:00 GMT 2007


Diego Novillo wrote:
> On 9/13/07, Mark Mitchell <mark@codesourcery.com> wrote:
>
>   
>> Do any of the other optimization maintainers have a feeling about this?
>>  Should we turn on vectorization at -O3, or are we not quite there yet?
>>     
>
> Anything inside of 5% in SPEC scores is noise.  Enabling vectorization
>   
I guess you meant 0.5% not 5%.  For SPEC2000 my observation that on some 
platforms it is even less (e.g. 0.3% for Intel Core2 server available to 
me).
> at -O3 sounds like a fine idea to me.  After all, we always say that
> -O3 is a "hopefully better" setting.
>
> IMO, the biggest gain is the stability it will bring to the vectorizer
> and the incentive to keep tuning the cost model.
>   



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