[llvm-commits] [llvm] r53040 - /llvm/trunk/lib/Transforms/Scalar/GVN.cpp

[Owen Anderson]

Author: resistor
Date: Wed Jul  2 13:15:31 2008
New Revision: 53040

URL: http://llvm.org/viewvc/llvm-project?rev=53040&view=rev
Log:
Avoid a redundant call.

Modified:
    llvm/trunk/lib/Transforms/Scalar/GVN.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/GVN.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/GVN.cpp?rev=53040&r1=53039&r2=53040&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/GVN.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/GVN.cpp Wed Jul  2 13:15:31 2008
@@ -808,10 +808,10 @@
   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) {