/// \brief This is similar to GetRCIdentityRoot but it stops as soon
/// as it finds a value with multiple uses.
static const Value *FindSingleUseIdentifiedObject(const Value *Arg) {
+ // ConstantData (like ConstantPointerNull and UndefValue) is used across
+ // modules. It's never a single-use value.
+ if (isa<ConstantData>(Arg))
+ return nullptr;
+
if (Arg->hasOneUse()) {
if (const BitCastInst *BC = dyn_cast<BitCastInst>(Arg))
return FindSingleUseIdentifiedObject(BC->getOperand(0));
ARCInstKind &Class) {
// Check for a return of the pointer value.
const Value *Ptr = GetArgRCIdentityRoot(AutoreleaseRV);
+
+ // If the argument is ConstantPointerNull or UndefValue, its other users
+ // aren't actually interesting to look at.
+ if (isa<ConstantData>(Ptr))
+ return;
+
SmallVector<const Value *, 2> Users;
Users.push_back(Ptr);
do {