Index: llvm/lib/Transforms/IPO/FunctionSpecialization.cpp
===================================================================
--- llvm/lib/Transforms/IPO/FunctionSpecialization.cpp
+++ llvm/lib/Transforms/IPO/FunctionSpecialization.cpp
@@ -216,6 +216,10 @@
         ValueToValueMapTy EmptyMap;
         Function *Clone = CloneFunction(F, EmptyMap);
         Argument *ClonedArg = Clone->arg_begin() + A.getArgNo();
+        // Functions with AvailableExternallyLinkage would be deleted
+        // in the end.
+        if (Clone->hasAvailableExternallyLinkage())
+          Clone->setLinkage(GlobalValue::InternalLinkage);
 
         // Rewrite calls to the function so that they call the clone instead.
         rewriteCallSites(F, Clone, *ClonedArg, C);
@@ -463,7 +467,8 @@
 
     // Determine if we can track the function's arguments. If so, add the
     // function to the solver's set of argument-tracked functions.
-    if (canTrackArgumentsInterprocedurally(&F)) {
+    if (canTrackArgumentsInterprocedurally(&F) ||
+        F.hasAvailableExternallyLinkage()) {
       LLVM_DEBUG(dbgs() << "FnSpecialization: Can track arguments\n");
       Solver.addArgumentTrackedFunction(&F);
       continue;