At each level of optimization, you can control the aggressiveness
of the optimizations performed.
Use the +Oconservative
option at optimization level 2, 3, or 4 if you are not sure if your
code conforms to standards. This option provides more safety.
Use the +Oaggressive
option at optimization level 2, 3, or 4 for best performance when
you are willing to risk changes to the behavior of your programs.
Using the +Oaggressive
option can cause your program to have compilation or run-time problems
that require troubleshooting.