diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 83e773e..c46271a 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -1690,9 +1690,9 @@
     return std::min(Tmp, Tmp2);
 
   case ISD::SELECT:
-    Tmp = ComputeNumSignBits(Op.getOperand(0), Depth+1);
+    Tmp = ComputeNumSignBits(Op.getOperand(1), Depth+1);
     if (Tmp == 1) return 1;  // Early out.
-    Tmp2 = ComputeNumSignBits(Op.getOperand(1), Depth+1);
+    Tmp2 = ComputeNumSignBits(Op.getOperand(2), Depth+1);
     return std::min(Tmp, Tmp2);
     
   case ISD::SETCC: