Index: llvm/trunk/include/llvm/IR/ModuleSummaryIndex.h
===================================================================
--- llvm/trunk/include/llvm/IR/ModuleSummaryIndex.h
+++ llvm/trunk/include/llvm/IR/ModuleSummaryIndex.h
@@ -408,6 +408,7 @@
     return const_cast<GlobalValueSummary &>(
                          static_cast<const AliasSummary *>(this)->getAliasee());
   }
+  bool hasAliaseeGUID() const { return AliaseeGUID != 0; }
   const GlobalValue::GUID &getAliaseeGUID() const {
     assert(AliaseeGUID && "Unexpected missing aliasee GUID");
     return AliaseeGUID;
Index: llvm/trunk/lib/IR/ModuleSummaryIndex.cpp
===================================================================
--- llvm/trunk/lib/IR/ModuleSummaryIndex.cpp
+++ llvm/trunk/lib/IR/ModuleSummaryIndex.cpp
@@ -198,9 +198,12 @@
          ", ffl: " + fflagsToString(FS->fflags());
 }
 
+static std::string getNodeVisualName(GlobalValue::GUID Id) {
+  return std::string("@") + std::to_string(Id);
+}
+
 static std::string getNodeVisualName(const ValueInfo &VI) {
-  return VI.name().empty() ? std::string("@") + std::to_string(VI.getGUID())
-                           : VI.name().str();
+  return VI.name().empty() ? getNodeVisualName(VI.getGUID()) : VI.name().str();
 }
 
 static std::string getNodeLabel(const ValueInfo &VI, GlobalValueSummary *GVS) {
@@ -221,13 +224,19 @@
 // specific module associated with it. Typically this is function
 // or variable defined in native object or library.
 static void defineExternalNode(raw_ostream &OS, const char *Pfx,
-                               const ValueInfo &VI) {
-  auto StrId = std::to_string(VI.getGUID());
-  OS << "  " << StrId << " [label=\"" << getNodeVisualName(VI)
-     << "\"]; // defined externally\n";
+                               const ValueInfo &VI, GlobalValue::GUID Id) {
+  auto StrId = std::to_string(Id);
+  OS << "  " << StrId << " [label=\"";
+
+  if (VI) {
+    OS << getNodeVisualName(VI);
+  } else {
+    OS << getNodeVisualName(Id);
+  }
+  OS << "\"]; // defined externally\n";
 }
 
-void ModuleSummaryIndex::exportToDot(raw_ostream& OS) const {
+void ModuleSummaryIndex::exportToDot(raw_ostream &OS) const {
   std::vector<Edge> CrossModuleEdges;
   DenseMap<GlobalValue::GUID, std::vector<uint64_t>> NodeMap;
   StringMap<GVSummaryMapTy> ModuleToDefinedGVS;
@@ -311,10 +320,17 @@
         Draw(SummaryIt.first, R.getGUID(), -1);
 
       if (auto *AS = dyn_cast_or_null<AliasSummary>(SummaryIt.second)) {
-        auto AliaseeOrigId = AS->getAliasee().getOriginalName();
-        auto AliaseeId = getGUIDFromOriginalID(AliaseeOrigId);
+        GlobalValue::GUID AliaseeId;
+        if (AS->hasAliaseeGUID())
+          AliaseeId = AS->getAliaseeGUID();
+        else {
+          auto AliaseeOrigId = AS->getAliasee().getOriginalName();
+          AliaseeId = getGUIDFromOriginalID(AliaseeOrigId);
+          if (!AliaseeId)
+            AliaseeId = AliaseeOrigId;
+        }
 
-        Draw(SummaryIt.first, AliaseeId ? AliaseeId : AliaseeOrigId, -2);
+        Draw(SummaryIt.first, AliaseeId, -2);
         continue;
       }
 
@@ -330,7 +346,7 @@
   for (auto &E : CrossModuleEdges) {
     auto &ModList = NodeMap[E.Dst];
     if (ModList.empty()) {
-      defineExternalNode(OS, "  ", getValueInfo(E.Dst));
+      defineExternalNode(OS, "  ", getValueInfo(E.Dst), E.Dst);
       // Add fake module to the list to draw an edge to an external node
       // in the loop below.
       ModList.push_back(-1);
Index: llvm/trunk/test/ThinLTO/X86/Inputs/alias_internal.ll
===================================================================
--- llvm/trunk/test/ThinLTO/X86/Inputs/alias_internal.ll
+++ llvm/trunk/test/ThinLTO/X86/Inputs/alias_internal.ll
@@ -0,0 +1,8 @@
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define internal i32 @f(i8*) unnamed_addr {
+    ret i32 42
+}
+
+@a2 = weak alias i32 (i8*), i32 (i8*)* @f
Index: llvm/trunk/test/ThinLTO/X86/alias_internal.ll
===================================================================
--- llvm/trunk/test/ThinLTO/X86/alias_internal.ll
+++ llvm/trunk/test/ThinLTO/X86/alias_internal.ll
@@ -0,0 +1,21 @@
+; Test to make sure dot dumper can correctly handle aliases to multiple
+; different internal aliasees with the same name.
+
+; RUN: opt -module-summary %s -o %t1.bc
+; RUN: opt -module-summary %p/Inputs/alias_internal.ll -o %t2.bc
+; RUN: llvm-lto2 run %t1.bc %t2.bc -o %t.out -save-temps \
+; RUN:   -r %t1.bc,a1,plx \
+; RUN:   -r %t2.bc,a2,plx
+
+; RUN: cat %t.out.index.dot | FileCheck %s
+; CHECK-DAG: M0_12511626713252727690 -> M0_{{.*}} // alias
+; CHECK-DAG: M1_8129049334585965161 -> M1_{{.*}} // alias
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define internal i32 @f(i8*) unnamed_addr {
+    ret i32 42
+}
+
+@a1 = weak alias i32 (i8*), i32 (i8*)* @f