diff --git a/llvm/include/llvm/ADT/Hashing.h b/llvm/include/llvm/ADT/Hashing.h
--- a/llvm/include/llvm/ADT/Hashing.h
+++ b/llvm/include/llvm/ADT/Hashing.h
@@ -683,4 +683,16 @@
 
 } // namespace llvm
 
+/// Implement std::hash so that hash_code can be used in STL containers.
+namespace std {
+
+template<>
+struct hash<llvm::hash_code> {
+  size_t operator()(llvm::hash_code const& Val) const {
+    return Val;
+  }
+};
+
+} // namespace std;
+
 #endif
diff --git a/llvm/include/llvm/ProfileData/SampleProf.h b/llvm/include/llvm/ProfileData/SampleProf.h
--- a/llvm/include/llvm/ProfileData/SampleProf.h
+++ b/llvm/include/llvm/ProfileData/SampleProf.h
@@ -1412,7 +1412,7 @@
 /// Note: when populating container, make sure to assign the SampleContext to
 /// the mapped value immediately because the key no longer holds it.
 class SampleProfileMap
-    : public HashKeyMap<DenseMap, SampleContext, FunctionSamples> {
+    : public HashKeyMap<std::unordered_map, SampleContext, FunctionSamples> {
 public:
   // Convenience method because this is being used in many places. Set the
   // FunctionSamples' context if its newly inserted.
@@ -1424,12 +1424,12 @@
   }
 
   iterator find(const SampleContext &Ctx) {
-    return HashKeyMap<llvm::DenseMap, SampleContext, FunctionSamples>::find(
+    return HashKeyMap<std::unordered_map, SampleContext, FunctionSamples>::find(
         Ctx);
   }
 
   const_iterator find(const SampleContext &Ctx) const {
-    return HashKeyMap<llvm::DenseMap, SampleContext, FunctionSamples>::find(
+    return HashKeyMap<std::unordered_map, SampleContext, FunctionSamples>::find(
         Ctx);
   }
 
@@ -1449,8 +1449,8 @@
   }
 
   size_t erase(const SampleContext &Ctx) {
-    return HashKeyMap<llvm::DenseMap, SampleContext, FunctionSamples>::erase(
-        Ctx);
+    return HashKeyMap<std::unordered_map, SampleContext, FunctionSamples>::
+        erase(Ctx);
   }
 
   size_t erase(const key_type &Key) { return base_type::erase(Key); }