Features/ArchitectureSupport - changing what we build for

[Kevin Kofler]

Callum Lerwick wrote:
> Going -O3 rather than -O2 is going to make a bigger difference than
> anything else. If you want to improve performance, you need to run
> profiles, locate performance critical bits of code, figure out if -O3 is
> beneficial, and/or write some hand tuned assembly/intrinsic code.
> 
> Not to mention, the biggest performance problem on modern processors is
> memory. Minimizing cache thrashing is way more important than what
> instructions you use. Optimize data structures before code.

That's actually an argument for investigating -Os, not -O3.

        Kevin Kofler