gcc -static -Os -march=native -fomit-frame-pointer -pipe -Wall  -Werror=pedantic  -Werror=implicit-function-declaration -pedantic -pedantic-errors -mpreferred-stack-boundary=4 -falign-functions=1 -falign-jumps=1 -falign-loops=1 -fno-unwind-tables -fdata-sections -ffunction-sections -Wl,--gc-sections -fno-asynchronous-unwind-tables -fstrict-aliasing -Wstrict-aliasing=2 -Wno-unused-function -std=c11 hello.c

Stripping:

strip -s a.out
strip -S --strip-unneeded --remove-section=.note.gnu.gold-version --remove-section=.comment --remove-section=.note --remove-section=.note.gnu.build-id --remove-section=.note.ABI-tag --remove-section=.eh_frame --remove-section=.eh_frame_ptr -R .note -R .comment -R .note.GNU-stack a.out
sstrip a.out