1 files changed, 6 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index 8370968065d..f88334a05ea 100644
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -508,8 +508,10 @@ private:
 
     // Keep a stack (SmallVector for efficiency) for depth-first traversal
     SmallVector<Value *, 8> DFT;
+    SmallPtrSet<Value *, 8> Visited;
 
     // Initialize
+    Visited.insert(V);
     DFT.push_back(V);
 
     while(!DFT.empty()) {
@@ -518,8 +520,10 @@ private:
       if (Instruction *I = dyn_cast<Instruction>(V)) {
         // If it is a || (or && depending on isEQ), process the operands.
         if (I->getOpcode() == (isEQ ? Instruction::Or : Instruction::And)) {
-          DFT.push_back(I->getOperand(1));
-          DFT.push_back(I->getOperand(0));
+          if (Visited.insert(I->getOperand(1)).second)
+            DFT.push_back(I->getOperand(1));
+          if (Visited.insert(I->getOperand(0)).second)
+            DFT.push_back(I->getOperand(0));
           continue;
         }