Optimize Options (Using the GNU Compiler Collection (GCC))
https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html
-Ofast の
> Disregard strict standards compliance. -Ofast enables all -O3 optimizations. It also enables optimizations that are not valid for all standard-compliant programs.
の勢いがヤバくて笑ってしまう