[InstCombine][NFC] Change cast of FixedVectorType to dyn_cast.

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
index c32f6ac..d6f8d2d 100644 (file)
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -1985,11 +1985,11 @@ Instruction *InstCombinerImpl::foldSelectExtConst(SelectInst &Sel) {
 static Instruction *canonicalizeSelectToShuffle(SelectInst &SI) {
   Value *CondVal = SI.getCondition();
   Constant *CondC;
-  if (!CondVal->getType()->isVectorTy() || !match(CondVal, m_Constant(CondC)))
+  auto *CondValTy = dyn_cast<FixedVectorType>(CondVal->getType());
+  if (!CondValTy || !match(CondVal, m_Constant(CondC)))
     return nullptr;
 
-  unsigned NumElts =
-      cast<FixedVectorType>(CondVal->getType())->getNumElements();
+  unsigned NumElts = CondValTy->getNumElements();
   SmallVector<int, 16> Mask;
   Mask.reserve(NumElts);
   for (unsigned i = 0; i != NumElts; ++i) {