diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 7c16652451b41..83c3c1689b190 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -3146,7 +3146,7 @@ void SelectionDAGBuilder::visitShift(const User &I, unsigned Opcode) {
     // count type has enough bits to represent any shift value, truncate
     // it now. This is a common case and it exposes the truncate to
     // optimization early.
-    else if (ShiftSize >= Log2_32_Ceil(Op2.getValueSizeInBits()))
+    else if (ShiftSize >= Log2_32_Ceil(Op1.getValueSizeInBits()))
       Op2 = DAG.getNode(ISD::TRUNCATE, DL, ShiftTy, Op2);
     // Otherwise we'll need to temporarily settle for some other convenient
     // type.  Type legalization will make adjustments once the shiftee is split.