From cb29a4f66a837c2d322ca08d4bcde7440a6f5cdc Mon Sep 17 00:00:00 2001
From: Owen Anderson <resistor@mac.com>
Date: Wed, 2 Jul 2008 18:15:31 +0000
Subject: [PATCH] Avoid a redundant call.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53040 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/GVN.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index 590227c27f9..498785e327a 100644
--- 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) {