// Make sure the first definition is not a partial redefinition. Add an
// <imp-def> of the full register.
+ // FIXME: LiveIntervals shouldn't modify the code like this. Whoever
+ // created the machine instruction should annotate it with <undef> flags
+ // as needed. Then we can simply assert here. The REG_SEQUENCE lowering
+ // is the main suspect.
if (MO.getSubReg()) {
mi->addRegisterDefined(interval.reg);
// Mark all defs of interval.reg on this instruction as reading <undef>.