Handle single-entry phi nodes gracefully in condprop.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62985 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/CondPropagate.cpp b/lib/Transforms/Scalar/CondPropagate.cpp
index 2e89943..f68fb29 100644
--- a/lib/Transforms/Scalar/CondPropagate.cpp
+++ b/lib/Transforms/Scalar/CondPropagate.cpp
@@ -126,6 +126,14 @@
   // one use (the branch), and is the only instruction besides the branch in the
   // block.
   PHINode *PN = cast<PHINode>(BI->getCondition());
+
+  if (PN->getNumIncomingValues() == 1) {
+    // Eliminate single-entry PHI nodes.
+    FoldSingleEntryPHINodes(PN->getParent());
+    return;
+  }
+  
+  
   if (!PN->hasOneUse()) return;
 
   BasicBlock *BB = BI->getParent();