// unit latency (defaultDefLatency may be too conservative).
#ifndef NDEBUG
if (SCDesc->isValid() && !DefMI->getOperand(DefOperIdx).isImplicit()
- && !DefMI->getDesc().OpInfo[DefOperIdx].isOptionalDef()) {
+ && !DefMI->getDesc().OpInfo[DefOperIdx].isOptionalDef()
+ && SchedModel.isComplete()) {
std::string Err;
raw_string_ostream ss(Err);
ss << "DefIdx " << DefIdx << " exceeds machine model writes for "