Fix bug: FunctionResolve/2003-07-23-CPR-Reference.ll

This fixes a long time annoyance which caused prototypes for bzero, bcopy,
bcmp, fputs, and fputs_unlocked to never get deleted.  Grr.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@7285 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/IPO/FunctionResolution.cpp b/lib/Transforms/IPO/FunctionResolution.cpp
index 8acddf590089153bc91b06a29e8e72a57c4711b2..86352d46a80adf3d89e07e02142ec6a5d3f229de 100644 (file)
--- a/lib/Transforms/IPO/FunctionResolution.cpp
+++ b/lib/Transforms/IPO/FunctionResolution.cpp
@@ -80,12 +80,14 @@ static bool ResolveFunctions(Module &M, std::vector<GlobalValue*> &Globals,
       // functions and that the Old function has no varargs fns specified.  In
       // otherwords it's just <retty> (...)
       //
-      Value *Replacement = Concrete;
-      if (Concrete->getType() != Old->getType())
-        Replacement = ConstantExpr::getCast(ConstantPointerRef::get(Concrete),
-                                            Old->getType());
-      NumResolved += Old->use_size();
-      Old->replaceAllUsesWith(Replacement);
+      if (!Old->use_empty()) {  // Avoid making the CPR unless we really need it
+        Value *Replacement = Concrete;
+        if (Concrete->getType() != Old->getType())
+          Replacement = ConstantExpr::getCast(ConstantPointerRef::get(Concrete),
+                                              Old->getType());
+        NumResolved += Old->use_size();
+        Old->replaceAllUsesWith(Replacement);
+      }
 
       // Since there are no uses of Old anymore, remove it from the module.
       M.getFunctionList().erase(Old);