https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78211
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Note -fcompare-debug compares the -fdump-final-insns= dumps, those include RTL, but not the LTO streams. So while it might not be very useful for -flto, there is no inherent reason why it wouldn't work. Of course more interesting is the comparison of -g/-g0 -fdump-final-insns= from the final compilation(s) by lto1.
