2018
https://developers.redhat.com/blog/2018/03/21/compiler-and-linker-flags-gcc/

-fPIC
    position-independent (for shared libs)
    https://renenyffenegger.ch/notes/development/languages/C-C-plus-plus/GCC/create-libraries/index
    https://www.cprogramming.com/tutorial/shared-libraries-linux-gcc.html

optimization
http://www.fsfla.org/~lxoliva/writeups/gOlogy/gOlogy.txt
-O3
-fomit-frame-pointer
-funroll-all-loops

profiling
-pg
LDFLAGS="-pg"

debug
-g

gcc @args.file

warnings
https://habr.com/ru/post/490850/