Index: lib/CodeGen/CGCall.cpp
===================================================================
--- lib/CodeGen/CGCall.cpp
+++ lib/CodeGen/CGCall.cpp
@@ -1200,8 +1200,10 @@
     llvm_unreachable("Invalid ABI kind for return argument");
   }
 
-  if (RetTy->isReferenceType())
+  if (RetTy->isReferenceType()) {
+    RetAttrs.addAttribute(llvm::Attribute::Dereferencable);
     RetAttrs.addAttribute(llvm::Attribute::NonNull);
+  }
 
   if (RetAttrs.hasAttributes())
     PAL.push_back(llvm::
@@ -1291,8 +1293,10 @@
     }
     }
 
-    if (ParamType->isReferenceType())
+    if (ParamType->isReferenceType()) {
+      Attrs.addAttribute(llvm::Attribute::Dereferencable);
       Attrs.addAttribute(llvm::Attribute::NonNull);
+    }
 
     if (Attrs.hasAttributes())
       PAL.push_back(llvm::AttributeSet::get(getLLVMContext(), Index, Attrs));