[Solved] What is option -O3 for g++ and nvcc?

It’s optimization on level 3, basically a shortcut for
several other options related to speed optimization etc. (see link below).

I can’t find any documentation on it.

… it is one of the best known options:

https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html

http://docs.nvidia.com/cuda/cuda-compiler-driver-nvcc/#options-for-altering-compiler-linker-behavior