RFD, draft patch: IRA costs for reg_equiv_invariant regs

[Bernd Schmidt]

On 06/02/2010 06:21 PM, Bernd Schmidt wrote:
> Can you redo these tests?  I just ran tests with current gcc sources.
> For 32 bit SPEC2k on a Westmere Xeon (essentially Core i7) I'm seeing  a
> minor perlbmk improvement with various compilation options including -O3
> -mpc64.

At one point I was even seeing a 10% perlbmk improvement with my patch,
but I didn't mention it since it went away.  Now that I've thought about
it - maybe what we're both seeing are artefacts of the "Turbo Boost"
functionality of recent Intel chips, i.e. one set of benchmarks being
run at a different clock speed?  It's probably a good idea to disable
that in the BIOS.


Bernd