The GCC Runtime Exception v3 might forbid that. That's one of the reasons why Apple and Google blew a gasket when GNU changed licenses and then poured billions into Clang. They wanted to be able to recompile your app store binaries on their backend to optimize for any hardware changes they made.

One workaround for that restriction is to use Cosmopolitan Libc: https://justine.lol/cosmopolitan/index.html It bundles compiler runtime libraries that are fast and permissively licensed. It lets you keep using GCC without facing restrictions on things like code morphing.