https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66631
--- Comment #16 from Stas Sergeev <stsp at users dot sourceforge.net> --- Actually, Andrew, do you think this is even TLS specific? No segregs are restored at all (not even DS, I was wrong saying it is), so is it guaranteed, if FS is restored by some other means, that gcc will not start using some "movs" instruction before init_handler(), or some ds-prefixed access? So, my guess is this: - If this is only TLS-specific and gcc really really doesn't want to implement a nice possibility of clobber segregs, then I'll probably start asking linux kernel people about a possible solution. After all, restoring TLS is their task. - BUT, if this is not TLS-specific but is unsafe with ANY segreg, then I think gcc should just allow clobber.
