This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: IRA performance regressions on PPC

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).

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]