IRA performance regressions on PPC

Vladimir Makarov vmakarov@redhat.com
Fri Sep 5 16:37:00 GMT 2008


Luis Machado wrote:
> Hi Vladimir,
>
> I was just going through some benchmarks on PPC and noticed that your
> patch from 08/26 (http://gcc.gnu.org/ml/gcc-cvs/2008-08/msg01152.html)
> caused a significant regression on both facerec (~17%) and applu (~4%)
> for 64-bit PPC.
>
> There are other degradations that i'm still working on isolating the
> cause, just to give you a heads up on the problem.
>   

Thanks for testing IRA, Luis.  Could you give me more details:
 
  What machine you are using for this?
  What options (especially march or mtune) you are using?  IRA is very 
sensitive to correct times of ld/st/moves in machine description.
  What is overall IRA regression on SPEC2000?

You could use the same version of the compiler with IRA (default) and 
old RA (-fno-ira).



More information about the Gcc mailing list