IRA performance regressions on PPC

[Luis Machado]

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.

Luis