c++linuxgcc

gcc -O4 optimization flag


What's the meaning of the -O4 optimization flag in gcc (3.2.3)? What's the difference to O3? When would you use one vs. the other?

The man pages only mention O, O0-3, Os, no word of the mysterious O4.


Solution

  • There is no -O4 in 3.2.3. Everything above -O3 results in -O3 being chosen.