Are people actively using the -liv-reduce option? See IndVarSimplify.cpp: static cl::opt<bool> ReduceLiveIVs("liv-reduce", cl::Hidden, cl::desc("Reduce live induction variables.")); -liv-reduce is an off-by-default internal option that splits <op>.with.overflow intrinsics into arithmetic and explicit overflow checks, so that SCEV can widen and optimize these. After two recent changes [0], "-liv-reduce" should no longer be necessary for SCEV to recognize and optimize overflow intrinsics, so I'd prefer to remove it unless there are people who actively depend on it. [0]: http://reviews.llvm.org/rL265912 and http://reviews.llvm.org/rL265913 -- Sanjoy