diff --git a/llvm/include/llvm/Transforms/IPO/FunctionImport.h b/llvm/include/llvm/Transforms/IPO/FunctionImport.h
index b5b969220df85..c06d96bbe62e2 100644
--- a/llvm/include/llvm/Transforms/IPO/FunctionImport.h
+++ b/llvm/include/llvm/Transforms/IPO/FunctionImport.h
@@ -149,6 +149,9 @@ class FunctionImporter {
     ImportMapTyImpl ImportMap;
   };
 
+  // A map from destination modules to lists of imports.
+  using ImportListsTy = DenseMap<StringRef, ImportMapTy>;
+
   /// The set contains an entry for every global value that the module exports.
   /// Depending on the user context, this container is allowed to contain
   /// definitions, declarations or a mix of both.
@@ -211,7 +214,7 @@ void ComputeCrossModuleImport(
     const DenseMap<StringRef, GVSummaryMapTy> &ModuleToDefinedGVSummaries,
     function_ref<bool(GlobalValue::GUID, const GlobalValueSummary *)>
         isPrevailing,
-    DenseMap<StringRef, FunctionImporter::ImportMapTy> &ImportLists,
+    FunctionImporter::ImportListsTy &ImportLists,
     DenseMap<StringRef, FunctionImporter::ExportSetTy> &ExportLists);
 
 /// PrevailingType enum used as a return type of callback passed
diff --git a/llvm/lib/LTO/LTO.cpp b/llvm/lib/LTO/LTO.cpp
index bd031338e8f39..09dfec03cb0c3 100644
--- a/llvm/lib/LTO/LTO.cpp
+++ b/llvm/lib/LTO/LTO.cpp
@@ -1716,8 +1716,7 @@ Error LTO::runThinLTO(AddStreamFn AddStream, FileCache Cache,
   // Synthesize entry counts for functions in the CombinedIndex.
   computeSyntheticCounts(ThinLTO.CombinedIndex);
 
-  DenseMap<StringRef, FunctionImporter::ImportMapTy> ImportLists(
-      ThinLTO.ModuleMap.size());
+  FunctionImporter::ImportListsTy ImportLists(ThinLTO.ModuleMap.size());
   DenseMap<StringRef, FunctionImporter::ExportSetTy> ExportLists(
       ThinLTO.ModuleMap.size());
   StringMap<std::map<GlobalValue::GUID, GlobalValue::LinkageTypes>> ResolvedODR;
diff --git a/llvm/lib/LTO/ThinLTOCodeGenerator.cpp b/llvm/lib/LTO/ThinLTOCodeGenerator.cpp
index f74202781a5f4..9d5a62fe10c8d 100644
--- a/llvm/lib/LTO/ThinLTOCodeGenerator.cpp
+++ b/llvm/lib/LTO/ThinLTOCodeGenerator.cpp
@@ -693,7 +693,7 @@ void ThinLTOCodeGenerator::promote(Module &TheModule, ModuleSummaryIndex &Index,
   computePrevailingCopies(Index, PrevailingCopy);
 
   // Generate import/export list
-  DenseMap<StringRef, FunctionImporter::ImportMapTy> ImportLists(ModuleCount);
+  FunctionImporter::ImportListsTy ImportLists(ModuleCount);
   DenseMap<StringRef, FunctionImporter::ExportSetTy> ExportLists(ModuleCount);
   ComputeCrossModuleImport(Index, ModuleToDefinedGVSummaries,
                            IsPrevailing(PrevailingCopy), ImportLists,
@@ -745,7 +745,7 @@ void ThinLTOCodeGenerator::crossModuleImport(Module &TheModule,
   computePrevailingCopies(Index, PrevailingCopy);
 
   // Generate import/export list
-  DenseMap<StringRef, FunctionImporter::ImportMapTy> ImportLists(ModuleCount);
+  FunctionImporter::ImportListsTy ImportLists(ModuleCount);
   DenseMap<StringRef, FunctionImporter::ExportSetTy> ExportLists(ModuleCount);
   ComputeCrossModuleImport(Index, ModuleToDefinedGVSummaries,
                            IsPrevailing(PrevailingCopy), ImportLists,
@@ -785,7 +785,7 @@ void ThinLTOCodeGenerator::gatherImportedSummariesForModule(
   computePrevailingCopies(Index, PrevailingCopy);
 
   // Generate import/export list
-  DenseMap<StringRef, FunctionImporter::ImportMapTy> ImportLists(ModuleCount);
+  FunctionImporter::ImportListsTy ImportLists(ModuleCount);
   DenseMap<StringRef, FunctionImporter::ExportSetTy> ExportLists(ModuleCount);
   ComputeCrossModuleImport(Index, ModuleToDefinedGVSummaries,
                            IsPrevailing(PrevailingCopy), ImportLists,
@@ -823,7 +823,7 @@ void ThinLTOCodeGenerator::emitImports(Module &TheModule, StringRef OutputName,
   computePrevailingCopies(Index, PrevailingCopy);
 
   // Generate import/export list
-  DenseMap<StringRef, FunctionImporter::ImportMapTy> ImportLists(ModuleCount);
+  FunctionImporter::ImportListsTy ImportLists(ModuleCount);
   DenseMap<StringRef, FunctionImporter::ExportSetTy> ExportLists(ModuleCount);
   ComputeCrossModuleImport(Index, ModuleToDefinedGVSummaries,
                            IsPrevailing(PrevailingCopy), ImportLists,
@@ -874,7 +874,7 @@ void ThinLTOCodeGenerator::internalize(Module &TheModule,
   computePrevailingCopies(Index, PrevailingCopy);
 
   // Generate import/export list
-  DenseMap<StringRef, FunctionImporter::ImportMapTy> ImportLists(ModuleCount);
+  FunctionImporter::ImportListsTy ImportLists(ModuleCount);
   DenseMap<StringRef, FunctionImporter::ExportSetTy> ExportLists(ModuleCount);
   ComputeCrossModuleImport(Index, ModuleToDefinedGVSummaries,
                            IsPrevailing(PrevailingCopy), ImportLists,
@@ -1074,7 +1074,7 @@ void ThinLTOCodeGenerator::run() {
 
   // Collect the import/export lists for all modules from the call-graph in the
   // combined index.
-  DenseMap<StringRef, FunctionImporter::ImportMapTy> ImportLists(ModuleCount);
+  FunctionImporter::ImportListsTy ImportLists(ModuleCount);
   DenseMap<StringRef, FunctionImporter::ExportSetTy> ExportLists(ModuleCount);
   ComputeCrossModuleImport(*Index, ModuleToDefinedGVSummaries,
                            IsPrevailing(PrevailingCopy), ImportLists,
diff --git a/llvm/lib/Transforms/IPO/FunctionImport.cpp b/llvm/lib/Transforms/IPO/FunctionImport.cpp
index 512f771a873aa..6227b085f13a6 100644
--- a/llvm/lib/Transforms/IPO/FunctionImport.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionImport.cpp
@@ -1111,7 +1111,7 @@ collectImportStatistics(const ModuleSummaryIndex &Index,
 #ifndef NDEBUG
 static bool checkVariableImport(
     const ModuleSummaryIndex &Index,
-    DenseMap<StringRef, FunctionImporter::ImportMapTy> &ImportLists,
+    FunctionImporter::ImportListsTy &ImportLists,
     DenseMap<StringRef, FunctionImporter::ExportSetTy> &ExportLists) {
   DenseSet<GlobalValue::GUID> FlattenedImports;
 
@@ -1152,7 +1152,7 @@ void llvm::ComputeCrossModuleImport(
     const DenseMap<StringRef, GVSummaryMapTy> &ModuleToDefinedGVSummaries,
     function_ref<bool(GlobalValue::GUID, const GlobalValueSummary *)>
         isPrevailing,
-    DenseMap<StringRef, FunctionImporter::ImportMapTy> &ImportLists,
+    FunctionImporter::ImportListsTy &ImportLists,
     DenseMap<StringRef, FunctionImporter::ExportSetTy> &ExportLists) {
   auto MIS = ModuleImportsManager::create(isPrevailing, Index, &ExportLists);
   // For each module that has function defined, compute the import/export lists.