diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 5d38fdd..480c068 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -2332,7 +2332,7 @@
     switch (Opcode) {
     default: break;
     case ISD::SIGN_EXTEND:
-      return getConstant(APInt(Val).sext(VT.getSizeInBits()), VT);
+      return getConstant(APInt(Val).sextOrTrunc(VT.getSizeInBits()), VT);
     case ISD::ANY_EXTEND:
     case ISD::ZERO_EXTEND:
     case ISD::TRUNCATE: