// Otherwise if all of the incoming values are the same for the PHI, replace
// the PHI node with the incoming value.
//
- Value *InVal = PN.getIncomingValue(0);
- for (unsigned i = 1, e = PN.getNumIncomingValues(); i != e; ++i)
- if (PN.getIncomingValue(i) != InVal)
- return 0; // Not the same, bail out.
+ Value *InVal = 0;
+ for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i)
+ if (PN.getIncomingValue(i) != &PN) // Not the PHI node itself...
+ if (InVal && PN.getIncomingValue(i) != InVal)
+ return 0; // Not the same, bail out.
+ else
+ InVal = PN.getIncomingValue(i);
+
+ // The only case that could cause InVal to be null is if we have a PHI node
+ // that only has entries for itself. In this case, there is no entry into the
+ // loop, so kill the PHI.
+ //
+ if (InVal == 0) InVal = Constant::getNullValue(PN.getType());
// All of the incoming values are the same, replace the PHI node now.
return ReplaceInstUsesWith(PN, InVal);