https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86680
--- Comment #7 from Florian La Roche <florian.laroche at googlemail dot com> --- Hello Andrew Pinski, shouldn't the compiler see that both must be aligned to 8 bytes and thus also their difference must be a multiple of 8 bytes? I haven't looked into gcc sources, but maybe this information could be exploited for additinal optimization. best regards, Florian La Roche