[InstCombine] clean up; NFC

llvm-svn: 268099
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
index 27e1f24..31eb6ae 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -898,7 +898,7 @@
 Value *InstCombiner::SimplifyDemandedVectorElts(Value *V, APInt DemandedElts,
                                                 APInt &UndefElts,
                                                 unsigned Depth) {
-  unsigned VWidth = cast<VectorType>(V->getType())->getNumElements();
+  unsigned VWidth = V->getType()->getVectorNumElements();
   APInt EltMask(APInt::getAllOnesValue(VWidth));
   assert((DemandedElts & ~EltMask) == 0 && "Invalid DemandedElts!");