https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94873
--- Comment #9 from Segher Boessenkool <segher at gcc dot gnu.org> --- "clobber" is a red herring; it is impossible to make a REG_EQ* note for a clobber, a clobber does not set a new value (that is the whole point of a clobber). I think we could allow auto-modify, sure, just as long as it stays clear what lhs the REG_EQ* note is talking about; and, as you say, everything needs to be audited for it :-/
