Re: [www] Document C++ -O0 improvements

[Gábor Lóki <loki at inf dot u-szeged dot hu>]

Paolo Bonzini wrote:

> > I am not against it but I need numbers and measurements. For instance, is GCC
> > 4.0 faster then 3.4 at building the kernel, or glibc, or other packages?
>
> Unluckily CSiBE only has -O2 and -Os.  I'll do some benchmarking.

And CSiBE has -O3, see at the Advanced queries section.

> This is unless Gábor beats me to the following request: could you tweak 
> CsiBE to do -O0 as well as -O2 and -Os?  The ability to compare with the 
> baseline gcc_3_4_0_release tag would be very useful.

We are planing to include all optimization flags into daily measurements,
but it need some time to speed up our measuring methods (because it takes
many resources to do it for all targets).
Although if you get the package you'll able to measure -O0.
Just use the -f _flag_ option when creating a config.

br,
  Gabor Loki