The change fix an assert fail at ScalarEvolutionExpander.cpp (generateOverflowCheck):
const SCEV *ExitCount = SE.getPredicatedBackedgeTakenCount(AR->getLoop(), Pred); assert(ExitCount != SE.getCouldNotCompute() && "Invalid loop count");
(generateOverflowCheck is called only from expandWrapPredicate)
by inserting an early check on SCEV PredicateBackEdgeCount when createAddRecFromPHIWithCastsImpl