GCC optimization
The new Issue of the Red Hat Magazine
has an interesting article about
"performance tuning with gcc", by one of the gcc devs.
Take a look at it, especially if you feel the constant need to use
obscure CFLAGS ;)
Some interesting quotes:
In most cases, obtaining the very last nanosecond of performance is not terribly important. Optimization follows a distinct
curve of diminishing returns. Most applications will thrive with the default transformations done at -O2, and since some of the more
esoteric flags are seldom used, your code may behave erratically because of latent bugs in your application (for example, the code
may be violating language aliasing rules).
and:
An even bigger problem is the interactions between optimizing transformations. It is not uncommon for different optimizations to
interfere or even cancel each other out, so by combining many different flags, you may be causing more harm than good.