title: What extra optimisation does g++ do with -Ofast?
body: <p>In g++ 4.6 (or later), what extra optimisations does -Ofast enable other than -ffast-math?</p>
  
  <p>The man page says this option "also enables optimizations that are not valid for all standard compliant programs". Where can I find more information about whether this might affect my program or not?</p>