diff --git a/include/llvm/ADT/FoldingSet.h b/include/llvm/ADT/FoldingSet.h
index 1465d04..c62c47d 100644
--- a/include/llvm/ADT/FoldingSet.h
+++ b/include/llvm/ADT/FoldingSet.h
@@ -18,7 +18,7 @@
 
 #include "llvm/Support/DataTypes.h"
 #include "llvm/ADT/SmallVector.h"
-#include <string>
+#include "llvm/ADT/StringRef.h"
 #include <iterator>
 
 namespace llvm {
@@ -227,9 +227,7 @@
   void AddInteger(long long I);
   void AddInteger(unsigned long long I);
   void AddBoolean(bool B) { AddInteger(B ? 1U : 0U); }
-  void AddString(const char* String, const char* End);
-  void AddString(const std::string &String);
-  void AddString(const char* String);
+  void AddString(StringRef String);
 
   template <typename T>
   inline void Add(const T& x) { FoldingSetTrait<T>::Profile(x, *this); }
diff --git a/lib/Support/FoldingSet.cpp b/lib/Support/FoldingSet.cpp
index 187ecdb..954dc77 100644
--- a/lib/Support/FoldingSet.cpp
+++ b/lib/Support/FoldingSet.cpp
@@ -63,14 +63,14 @@
     Bits.push_back(unsigned(I >> 32));
 }
 
-void FoldingSetNodeID::AddString(const char *String, const char *End) {
-  unsigned Size =  static_cast<unsigned>(End - String);
+void FoldingSetNodeID::AddString(StringRef String) {
+  unsigned Size =  String.size();
   Bits.push_back(Size);
   if (!Size) return;
 
   unsigned Units = Size / 4;
   unsigned Pos = 0;
-  const unsigned *Base = (const unsigned *)String;
+  const unsigned *Base = (const unsigned*) String.data();
   
   // If the string is aligned do a bulk transfer.
   if (!((intptr_t)Base & 3)) {
@@ -100,14 +100,6 @@
   Bits.push_back(V);
 }
 
-void FoldingSetNodeID::AddString(const char *String) {
-  AddString(String, String + strlen(String));
-}
-
-void FoldingSetNodeID::AddString(const std::string &String) {
-  AddString(&*String.begin(), &*String.end());
-}
-
 /// ComputeHash - Compute a strong hash value for this FoldingSetNodeID, used to 
 /// lookup the node in the FoldingSetImpl.
 unsigned FoldingSetNodeID::ComputeHash() const {