- unsigned BitWidth = cast<IntegerType>(V->getType())->getBitWidth();
- APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
- ComputeMaskedBits(V, KnownZero, KnownOne, TD);
- return KnownZero.isAllOnesValue();
+ // Per-component check doesn't work with zeroinitializer
+ Constant *C = dyn_cast<Constant>(V);
+ if (!C)
+ return false;
+
+ if (C->isZeroValue())
+ return true;
+
+ // For a vector, KnownZero will only be true if all values are zero, so check
+ // this per component
+ unsigned BitWidth = VecTy->getElementType()->getIntegerBitWidth();
+ for (unsigned I = 0, N = VecTy->getNumElements(); I != N; ++I) {
+ Constant *Elem = C->getAggregateElement(I);
+ if (isa<UndefValue>(Elem))
+ return true;
+
+ APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
+ computeKnownBits(Elem, KnownZero, KnownOne, DL);
+ if (KnownZero.isAllOnesValue())
+ return true;
+ }
+
+ return false;