https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90007
--- Comment #4 from Alexander Monakov <amonakov at gcc dot gnu.org> --- Well, often sel-sched just does not discriminate hardregs and pseudos when checking if renaming/substitution may be applied. Sure, as a matter of efficiency we should probably disallow substitution through such mixed pseudo=hardreg assignments. Nevertheless, if it's not only a matter of optimization, but also of internal consistency, then I'd like to understand it better. Hence the question in comment #2.
