Avoid a redundant call.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53040 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index 590227c27f95e9f6c9850c64a34737725dc08304..498785e327a4b1536b9ca4a6915a8d01bd6721cc 100644 (file)
--- a/lib/Transforms/Scalar/GVN.cpp
+++ b/lib/Transforms/Scalar/GVN.cpp
@@ -808,10 +808,10 @@ Value *GVN::GetValueForBlock(BasicBlock *BB, LoadInst* orig,
   DenseMap<BasicBlock*, Value*>::iterator V = Phis.find(BB);
   if (V != Phis.end() && !top_level) return V->second;
   
-  if (!getAnalysis<DominatorTree>().isReachableFromEntry(BB)) {
-    Phis[BB] = UndefValue::get(orig->getType());
-    return UndefValue::get(orig->getType());
-  }
+  // If the block is unreachable, just return undef, since this path
+  // can't actually occur at runtime.
+  if (!getAnalysis<DominatorTree>().isReachableFromEntry(BB))
+    return Phis[BB] = UndefValue::get(orig->getType());
   
   BasicBlock* singlePred = BB->getSinglePredecessor();
   if (singlePred) {