diff options
| -rw-r--r-- | lib/VMCore/Instructions.cpp | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/lib/VMCore/Instructions.cpp b/lib/VMCore/Instructions.cpp index d9c20872f8..7de5602f08 100644 --- a/lib/VMCore/Instructions.cpp +++ b/lib/VMCore/Instructions.cpp @@ -138,8 +138,11 @@ void PHINode::resizeOperands(unsigned NumOps) { Value *PHINode::hasConstantValue(bool AllowNonDominatingInstruction) const { // If the PHI node only has one incoming value, eliminate the PHI node... if (getNumIncomingValues() == 1) - return getIncomingValue(0); - + if (getIncomingValue(0) != this) // not X = phi X + return getIncomingValue(0); + else + return UndefValue::get(getType()); // Self cycle is dead. + // Otherwise if all of the incoming values are the same for the PHI, replace // the PHI node with the incoming value. // |