vendor/llvm/llvm-r86025

1 files changed, 9 insertions, 0 deletions

diff --git a/lib/Transforms/Utils/InlineFunction.cpp b/lib/Transforms/Utils/InlineFunction.cpp
index 619c939064d3..20f5a4a94238 100644
--- a/lib/Transforms/Utils/InlineFunction.cpp
+++ b/lib/Transforms/Utils/InlineFunction.cpp
@@ -619,8 +619,17 @@ bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD,
                "Ret value not consistent in function!");
         PHI->addIncoming(RI->getReturnValue(), RI->getParent());
       }
+    
+      // Now that we inserted the PHI, check to see if it has a single value
+      // (e.g. all the entries are the same or undef).  If so, remove the PHI so
+      // it doesn't block other optimizations.
+      if (Value *V = PHI->hasConstantValue()) {
+        PHI->replaceAllUsesWith(V);
+        PHI->eraseFromParent();
+      }
     }
 
+
     // Add a branch to the merge points and remove return instructions.
     for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
       ReturnInst *RI = Returns[i];