Index: lib/CodeGen/AsmPrinter/CodeViewDebug.h
===================================================================
--- lib/CodeGen/AsmPrinter/CodeViewDebug.h
+++ lib/CodeGen/AsmPrinter/CodeViewDebug.h
@@ -117,10 +117,8 @@
   /// to be confused with type indices for LF_FUNC_ID records.
   unsigned NextFuncId = 0;
 
-  codeview::TypeIndex VoidFnTyIdx;
-
-  /// Get a type index for a generic void function type.
-  codeview::TypeIndex getGenericFunctionTypeIndex();
+  codeview::TypeIndex
+  getFunctionTypeIndex(const DISubroutineType *SubroutineTy);
 
   InlineSite &getInlineSite(const DILocation *InlinedAt,
                             const DISubprogram *Inlinee);
Index: lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
+++ lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
@@ -122,24 +122,43 @@
   return *Site;
 }
 
-TypeIndex CodeViewDebug::getGenericFunctionTypeIndex() {
-  if (VoidFnTyIdx.getIndex() != 0)
-    return VoidFnTyIdx;
+TypeIndex
+CodeViewDebug::getFunctionTypeIndex(const DISubroutineType *SubroutineTy) {
+  // Check if we've already translated this type.
+  auto I = TypeIndices.find(SubroutineTy);
+  if (I != TypeIndices.end())
+    return I->second;
+
+  SmallVector<TypeIndex, 8> ReturnAndArgTypeIndices;
+  for (DITypeRef ArgTypeRef : SubroutineTy->getTypeArray())
+    ReturnAndArgTypeIndices.push_back(getTypeIndex(ArgTypeRef));
+
+  TypeIndex ReturnTypeIndex = TypeIndex::Void();
+  ArrayRef<TypeIndex> ArgTypeIndices = None;
+  if (!ReturnAndArgTypeIndices.empty()) {
+    auto ReturnAndArgTypesRef = makeArrayRef(ReturnAndArgTypeIndices);
+    ReturnTypeIndex = ReturnAndArgTypesRef.front();
+    ArgTypeIndices = ReturnAndArgTypesRef.drop_front();
+  }
 
-  ArrayRef<TypeIndex> NoArgs;
-  ArgListRecord ArgListRec(TypeRecordKind::ArgList, NoArgs);
+  ArgListRecord ArgListRec(TypeRecordKind::ArgList, ArgTypeIndices);
   TypeIndex ArgListIndex = TypeTable.writeArgList(ArgListRec);
 
-  ProcedureRecord Procedure(TypeIndex::Void(), CallingConvention::NearC,
+  ProcedureRecord Procedure(ReturnTypeIndex, CallingConvention::NearC,
                             FunctionOptions::None, 0, ArgListIndex);
-  VoidFnTyIdx = TypeTable.writeProcedure(Procedure);
-  return VoidFnTyIdx;
+  TypeIndex TI = TypeTable.writeProcedure(Procedure);
+
+  auto InsertResult = TypeIndices.insert({SubroutineTy, TI});
+  (void)InsertResult;
+  assert(InsertResult.second && "DISubroutineType lowered twice");
+  return TI;
 }
 
 void CodeViewDebug::recordFuncIdForSubprogram(const DISubprogram *SP) {
   TypeIndex ParentScope = TypeIndex(0);
   StringRef DisplayName = SP->getDisplayName();
-  FuncIdRecord FuncId(ParentScope, getGenericFunctionTypeIndex(), DisplayName);
+  FuncIdRecord FuncId(ParentScope, getFunctionTypeIndex(SP->getType()),
+                      DisplayName);
   TypeIndex TI = TypeTable.writeFuncId(FuncId);
   TypeIndices[SP] = TI;
 }
@@ -495,7 +514,11 @@
     OS.AddComment("Offset before epilogue");
     OS.EmitIntValue(0, 4);
     OS.AddComment("Function type index");
-    OS.EmitIntValue(0, 4);
+    if (const DISubprogram *Subprogram = GV->getSubprogram())
+      OS.EmitIntValue(getFunctionTypeIndex(Subprogram->getType()).getIndex(),
+                      4);
+    else
+      OS.EmitIntValue(0, 4);
     OS.AddComment("Function section relative address");
     OS.EmitCOFFSecRel32(Fn);
     OS.AddComment("Function section index");