[SelectionDAG] Use isa to silence unused variable warning (NFC).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316257 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index dfb097ac770406f47d43ec747a825f8f4c61498f..63f9198d594233d6e9f581721deddc913e4846d9 100644 (file)
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -2966,7 +2966,7 @@ unsigned SelectionDAG::ComputeNumSignBits(SDValue Op, const APInt &DemandedElts,
   unsigned Tmp, Tmp2;
   unsigned FirstAnswer = 1;
 
-  if (auto *C = dyn_cast<ConstantSDNode>(Op)) {
+  if (isa<ConstantSDNode>(Op)) {
     const APInt &Val = cast<ConstantSDNode>(Op)->getAPIntValue();
     return Val.getNumSignBits();
   }