https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95556 --- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> --- See -mno-align-stringops, -minline-all-stringops, -minline-stringops-dynamically, -mstringop-strategy= , -mmemcpy-strategy= options and their documentation in the GCC manual.