Neaten up this method. Check that if there is only one

predecessor then it's Src.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149843 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index f6d6b90b99a212eae44e27891803293887b5ca69..654125342a4156c8ddcc113fcb457b22e654d39f 100644 (file)
--- a/lib/Transforms/Scalar/GVN.cpp
+++ b/lib/Transforms/Scalar/GVN.cpp
@@ -1999,10 +1999,10 @@ static bool isOnlyReachableViaThisEdge(BasicBlock *Src, BasicBlock *Dst,
   // only reachable from Src, in practice it is pointless since at the time
   // GVN runs all such loops have preheaders, which means that Dst will have
   // been changed to have only one predecessor, namely Src.
-  pred_iterator PI = pred_begin(Dst), PE = pred_end(Dst);
-  assert(PI != PE && "No edge between these basic blocks!");
+  BasicBlock *Pred = Dst->getSinglePredecessor();
+  assert((!Pred || Pred == Src) && "No edge between these basic blocks!");
   (void)Src;
-  return PE == ++PI;
+  return Pred != 0;
 }
 
 /// processInstruction - When calculating availability, handle an instruction