ich is <tt>-O3</tt> in the current version.
</p>
<p>
The second form adds or removes individual optimization flags.
The third form sets a parameter for the VM or the JIT compiler
to a specific value.
</p>
<p>
You can either use this option multiple times (like <tt>-Ocse
-O-dce -Ohotloop=10</tt>) or separate several settings with a comma
(like <tt>-O+cse,-dce,hotloop=10</tt>). The settings are applied from
left to right and later settings override earlier ones. You can freely
mix the three forms, but note th