[Nauty] Squeezing out another 10%...

[Brendan McKay]

* Chris Jefferson <caj at cs.york.ac.uk> [050214 23:36]:
> 
> Just one very minor note. There is no difference at all between -O3 and 
> higher values, the higher values are just allowed for backwards 
> compatability when they used to higher.

That's true for gcc, yes. The configuration file tries to work for
multiple compilers by testing -O4, -O3, -O2, -O in succession and
using the first one that is not rejected by the compiler. It chooses
-O4 for gcc because that is accepted.

Brendan.