https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100960
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Slightly related was https://gcc.gnu.org/legacy-ml/gcc-patches/2010-03/msg01379.html So, perhaps for the case where we do not track the source register in the wider mode we could for var-tracking purpose also pretend the move is not a DImode copy, but a SImode copy. But what I wrote above is also an option, record permanent equivalency that the narrower value is lowpart subreg of the wider value.
