Enabling -frename-registers?

[Eric Botcazou]

> The IBM LTC team has tested the benefit of -frename-registers at -O2
> and sees no net benefit for PowerPC -- some benchmarks improve
> slightly but others degrade slightly (a few percent).  You mentioned
> no overall benefit for x86.  Although you mentioned benefit for
> Itanium, it is not a primary nor secondary architecture target for GCC
> and continues to have limited adoption.  Andreas also reported a
> bootstrap comparison failure for Itanium due to the change.

...which had nothing to do with -frename-registers but was a latent issue in 
the speculation support of the scheduler, see the audit trail.

-- 
Eric Botcazou