diff --git a/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp b/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
--- a/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
+++ b/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
@@ -125,7 +125,7 @@
 
 static bool processSelect(SelectInst *S, LazyValueInfo *LVI) {
   if (S->getType()->isVectorTy()) return false;
-  if (isa<Constant>(S->getOperand(0))) return false;
+  if (isa<Constant>(S->getCondition())) return false;
 
   Constant *C = LVI->getConstant(S->getCondition(), S->getParent(), S);
   if (!C) return false;
@@ -133,11 +133,7 @@
   ConstantInt *CI = dyn_cast<ConstantInt>(C);
   if (!CI) return false;
 
-  Value *ReplaceWith = S->getTrueValue();
-  Value *Other = S->getFalseValue();
-  if (!CI->isOne()) std::swap(ReplaceWith, Other);
-  if (ReplaceWith == S) ReplaceWith = UndefValue::get(S->getType());
-
+  Value *ReplaceWith = CI->isOne() ? S->getTrueValue() : S->getFalseValue();
   S->replaceAllUsesWith(ReplaceWith);
   S->eraseFromParent();