[SplitModule] In split module utility we should never separate alias with its aliasee.

Summary: When splitting module with preserving locals, we currently do not handle case of global alias being separated with its aliasee.

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16585

llvm-svn: 259075

llvm/lib/Transforms/Utils/SplitModule.cpp

@@ -88,6 +88,13 @@ static void findPartitions(Module *M, ClusterIDMapType &ClusterIDMap,
         Member = &GV;
     }
 
+    // For aliases we should not separate them from their aliasees regardless
+    // of linkage.
+    if (GlobalAlias *GA = dyn_cast<GlobalAlias>(&GV)) {
+      if (const GlobalObject *Base = GA->getBaseObject())
+        GVtoClusterMap.unionSets(&GV, Base);
+    }
+
     // Further only iterate over local GVs.
     if (!GV.hasLocalLinkage())
       return;