Index: lib/Linker/IRMover.cpp
===================================================================
--- lib/Linker/IRMover.cpp
+++ lib/Linker/IRMover.cpp
@@ -388,7 +388,6 @@
   /// due to the use of Value handles which the Linker doesn't actually need,
   /// but this allows us to reuse the ValueMapper code.
   ValueToValueMapTy ValueMap;
-  ValueToValueMapTy AliasValueMap;
 
   DenseSet<GlobalValue *> ValuesToLink;
   std::vector<GlobalValue *> Worklist;
@@ -1056,15 +1055,15 @@
 
   bool ShouldLink = shouldLink(DGV, *SGV);
 
-  // just missing from map
+  /// First verify if the value hasn't been alreay linked, which should not be
+  /// possible without ShouldLink
   if (ShouldLink) {
     auto I = ValueMap.find(SGV);
     if (I != ValueMap.end())
       return cast<Constant>(I->second);
-
-    I = AliasValueMap.find(SGV);
-    if (I != AliasValueMap.end())
-      return cast<Constant>(I->second);
+  } else {
+    assert(ValueMap.find(SGV) == ValueMap.end() &&
+           "'!ShouldLink' GV shouldn't be in the ValueMap, broken invariant");
   }
 
   if (!ShouldLink && ForAlias)
@@ -1196,7 +1195,7 @@
 
 void IRLinker::linkAliasBody(GlobalAlias &Dst, GlobalAlias &Src) {
   Constant *Aliasee = Src.getAliasee();
-  Constant *Val = MapValue(Aliasee, AliasValueMap, ValueMapperFlags, &TypeMap,
+  Constant *Val = MapValue(Aliasee, ValueMap, ValueMapperFlags, &TypeMap,
                            &LValMaterializer);
   Dst.setAliasee(Val);
 }
@@ -1555,8 +1554,7 @@
     Worklist.pop_back();
 
     // Already mapped.
-    if (ValueMap.find(GV) != ValueMap.end() ||
-        AliasValueMap.find(GV) != AliasValueMap.end())
+    if (ValueMap.find(GV) != ValueMap.end())
       continue;
 
     assert(!GV->isDeclaration());