> -O3 If size is really important, you probably want to try -Os (optimize for size) and -Oz (try harder to optimize for size, including at the expense of CPU)

> -O3 If size is really important, you probably want to try -Os (optimize for size) and -Oz (try harder to optimize for size, including at the expense of CPU) as well. > LTO If your project gets big enough that -flto results in unacceptable link times, try -flto=thin.