diff --git a/include/swift/AST/Decl.h b/include/swift/AST/Decl.h
index 2cd9e47..1ebe6ca 100644
--- a/include/swift/AST/Decl.h
+++ b/include/swift/AST/Decl.h
@@ -37,6 +37,7 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/Support/TrailingObjects.h"
+#include <type_traits>
 
 namespace swift {
   enum class AccessSemantics : unsigned char;
@@ -6765,6 +6766,9 @@
 std::pair<DefaultArgumentKind, Type>
 getDefaultArgumentInfo(ValueDecl *source, unsigned Index);
 
+/// Display ValueDecl subclasses.
+void simple_display(llvm::raw_ostream &out, const ValueDecl *&decl);
+
 } // end namespace swift
 
 #endif
diff --git a/include/swift/Basic/SimpleDisplay.h b/include/swift/Basic/SimpleDisplay.h
index 4033ad0..d2062b4 100644
--- a/include/swift/Basic/SimpleDisplay.h
+++ b/include/swift/Basic/SimpleDisplay.h
@@ -25,7 +25,36 @@
 
 namespace swift {
   template<typename T>
-  void simple_display(llvm::raw_ostream &out, const T &value) {
+  struct HasTrivialDisplay {
+    static const bool value = false;
+  };
+
+#define HAS_TRIVIAL_DISPLAY(Type)     \
+  template<>                          \
+  struct HasTrivialDisplay<Type> {    \
+    static const bool value = true;   \
+  }
+
+  HAS_TRIVIAL_DISPLAY(unsigned char);
+  HAS_TRIVIAL_DISPLAY(signed char);
+  HAS_TRIVIAL_DISPLAY(char);
+  HAS_TRIVIAL_DISPLAY(short);
+  HAS_TRIVIAL_DISPLAY(unsigned short);
+  HAS_TRIVIAL_DISPLAY(int);
+  HAS_TRIVIAL_DISPLAY(unsigned int);
+  HAS_TRIVIAL_DISPLAY(long);
+  HAS_TRIVIAL_DISPLAY(unsigned long);
+  HAS_TRIVIAL_DISPLAY(long long);
+  HAS_TRIVIAL_DISPLAY(unsigned long long);
+  HAS_TRIVIAL_DISPLAY(float);
+  HAS_TRIVIAL_DISPLAY(double);
+  HAS_TRIVIAL_DISPLAY(bool);
+
+#undef HAS_TRIVIAL_DISPLAY
+
+  template<typename T>
+  typename std::enable_if<HasTrivialDisplay<T>::value>::type
+  simple_display(llvm::raw_ostream &out, const T &value) {
     out << value;
   }
 
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index cc9168b..5dc6783 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -5731,3 +5731,8 @@
   return getAsDeclContext()->getAsNominalTypeOrNominalTypeExtensionContext();
 }
 bool TypeOrExtensionDecl::isNull() const { return Decl.isNull(); }
+
+void swift::simple_display(llvm::raw_ostream &out, const ValueDecl *&decl) {
+  if (decl) decl->dumpRef(out);
+  else out << "(null)";
+}
diff --git a/test/decl/class/circular_inheritance.swift b/test/decl/class/circular_inheritance.swift
index 5696455..f4dad62 100644
--- a/test/decl/class/circular_inheritance.swift
+++ b/test/decl/class/circular_inheritance.swift
@@ -42,7 +42,7 @@
 }
 
 // CHECK: ===CYCLE DETECTED===
-// CHECK-NEXT: `--{{.*}}SuperclassTypeRequest
+// CHECK-NEXT: `--{{.*}}SuperclassTypeRequest({{.*Left}}
 // CHECK-NEXT:      `--{{.*}}InheritedTypeRequest(circular_inheritance.(file).Left@
 // CHECK-NEXT:          `--{{.*}}SuperclassTypeRequest
 // CHECK-NEXT:              `--{{.*}}InheritedTypeRequest(circular_inheritance.(file).Right@