Constant fold bitconvert(undef)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27391 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 6eb6570..a2b575f 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -1167,6 +1167,8 @@
if (VT == Operand.getValueType()) return Operand; // noop conversion.
if (OpOpcode == ISD::BIT_CONVERT) // bitconv(bitconv(x)) -> bitconv(x)
return getNode(ISD::BIT_CONVERT, VT, Operand.getOperand(0));
+ if (OpOpcode == ISD::UNDEF)
+ return getNode(ISD::UNDEF, VT);
break;
case ISD::SCALAR_TO_VECTOR:
assert(MVT::isVector(VT) && !MVT::isVector(Operand.getValueType()) &&