Index: include/llvm/ADT/SmallSet.h
===================================================================
--- include/llvm/ADT/SmallSet.h
+++ include/llvm/ADT/SmallSet.h
@@ -15,26 +15,26 @@
 #define LLVM_ADT_SMALLSET_H
 
 #include "llvm/ADT/None.h"
+#include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallVector.h"
-#include <set>
 
 namespace llvm {
 
-/// SmallSet - This maintains a set of unique values, optimizing for the case
-/// when the set is small (less than N).  In this case, the set can be
-/// maintained with no mallocs.  If the set gets large, we expand to using an
-/// std::set to maintain reasonable lookup times.
+/// This maintains a set of unique values, optimizing for the case when the set
+/// is small (less than N).  In this case, the set can be maintained with no
+/// mallocs.  If the set gets large, we expand to using another implementation
+/// to maintain reasonable lookup times.
 ///
 /// Note that this set does not provide a way to iterate over members in the
 /// set.
-template <typename T, unsigned N,  typename C = std::less<T> >
+template <typename T, unsigned N, typename BigSet = DenseSet<T>>
 class SmallSet {
   /// Use a SmallVector to hold the elements here (even though it will never
   /// reach its 'large' stage) to avoid calling the default ctors of elements
   /// we will never use.
   SmallVector<T, N> Vector;
-  std::set<T, C> Set;
+  BigSet Set;
   typedef typename SmallVector<T, N>::const_iterator VIterator;
   typedef typename SmallVector<T, N>::iterator mutable_iterator;
 
Index: lib/Analysis/AliasAnalysisEvaluator.cpp
===================================================================
--- lib/Analysis/AliasAnalysisEvaluator.cpp
+++ lib/Analysis/AliasAnalysisEvaluator.cpp
@@ -31,6 +31,7 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
+#include <set>
 using namespace llvm;
 
 static cl::opt<bool> PrintAll("print-all-alias-modref-info", cl::ReallyHidden);
@@ -145,7 +146,7 @@
   AliasAnalysis &AA = getAnalysis<AAResultsWrapperPass>().getAAResults();
 
   SetVector<Value *> Pointers;
-  SetVector<CallSite> CallSites;
+  SetVector<CallSite, std::vector<CallSite>, std::set<CallSite>> CallSites;
   SetVector<Value *> Loads;
   SetVector<Value *> Stores;
 
Index: lib/CodeGen/AggressiveAntiDepBreaker.h
===================================================================
--- lib/CodeGen/AggressiveAntiDepBreaker.h
+++ lib/CodeGen/AggressiveAntiDepBreaker.h
@@ -28,6 +28,7 @@
 #include "llvm/Target/TargetRegisterInfo.h"
 #include "llvm/Target/TargetSubtargetInfo.h"
 #include <map>
+#include <set>
 
 namespace llvm {
 class RegisterClassInfo;
Index: lib/CodeGen/SelectionDAG/SelectionDAG.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -51,6 +51,7 @@
 #include <algorithm>
 #include <cmath>
 #include <utility>
+#include <set>
 
 using namespace llvm;
 
Index: lib/ExecutionEngine/Orc/OrcMCJITReplacement.h
===================================================================
--- lib/ExecutionEngine/Orc/OrcMCJITReplacement.h
+++ lib/ExecutionEngine/Orc/OrcMCJITReplacement.h
@@ -20,6 +20,7 @@
 #include "llvm/ExecutionEngine/Orc/LazyEmittingLayer.h"
 #include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h"
 #include "llvm/Object/Archive.h"
+#include <set>
 
 namespace llvm {
 namespace orc {
Index: lib/Target/AMDGPU/R600ControlFlowFinalizer.cpp
===================================================================
--- lib/Target/AMDGPU/R600ControlFlowFinalizer.cpp
+++ lib/Target/AMDGPU/R600ControlFlowFinalizer.cpp
@@ -23,6 +23,7 @@
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/Support/raw_ostream.h"
+#include <set>
 
 using namespace llvm;
 
Index: lib/Target/X86/X86FrameLowering.cpp
===================================================================
--- lib/Target/X86/X86FrameLowering.cpp
+++ lib/Target/X86/X86FrameLowering.cpp
@@ -32,6 +32,7 @@
 #include "llvm/Target/TargetOptions.h"
 #include "llvm/Support/Debug.h"
 #include <cstdlib>
+#include <set>
 
 using namespace llvm;
 
@@ -177,7 +178,7 @@
   case X86::TCRETURNmi64:
   case X86::EH_RETURN:
   case X86::EH_RETURN64: {
-    SmallSet<uint16_t, 8> Uses;
+    SmallSet<uint16_t, 8, std::set<uint16_t>> Uses;
     for (unsigned i = 0, e = MBBI->getNumOperands(); i != e; ++i) {
       MachineOperand &MO = MBBI->getOperand(i);
       if (!MO.isReg() || MO.isDef())
Index: lib/Transforms/IPO/MergeFunctions.cpp
===================================================================
--- lib/Transforms/IPO/MergeFunctions.cpp
+++ lib/Transforms/IPO/MergeFunctions.cpp
@@ -113,6 +113,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
 #include <vector>
+#include <set>
 
 using namespace llvm;
 
Index: utils/TableGen/AsmMatcherEmitter.cpp
===================================================================
--- utils/TableGen/AsmMatcherEmitter.cpp
+++ utils/TableGen/AsmMatcherEmitter.cpp
@@ -1721,8 +1721,10 @@
   }
 }
 
-static unsigned getConverterOperandID(const std::string &Name,
-                                      SetVector<std::string> &Table,
+typedef SetVector<std::string, std::vector<std::string>, std::set<std::string>>
+    StringSet;
+
+static unsigned getConverterOperandID(const std::string &Name, StringSet &Table,
                                       bool &IsNew) {
   IsNew = Table.insert(Name);
 
@@ -1738,8 +1740,8 @@
 static void emitConvertFuncs(CodeGenTarget &Target, StringRef ClassName,
                              std::vector<std::unique_ptr<MatchableInfo>> &Infos,
                              raw_ostream &OS) {
-  SetVector<std::string> OperandConversionKinds;
-  SetVector<std::string> InstructionConversionKinds;
+  StringSet OperandConversionKinds;
+  StringSet InstructionConversionKinds;
   std::vector<std::vector<uint8_t> > ConversionTable;
   size_t MaxRowLength = 2; // minimum is custom converter plus terminator.
 
Index: utils/TableGen/FixedLenDecoderEmitter.cpp
===================================================================
--- utils/TableGen/FixedLenDecoderEmitter.cpp
+++ utils/TableGen/FixedLenDecoderEmitter.cpp
@@ -65,8 +65,12 @@
 typedef uint32_t DecoderFixup;
 typedef std::vector<DecoderFixup> FixupList;
 typedef std::vector<FixupList> FixupScopeList;
-typedef SetVector<std::string> PredicateSet;
-typedef SetVector<std::string> DecoderSet;
+
+typedef SetVector<std::string, std::vector<std::string>, std::set<std::string>>
+    StringSet;
+
+typedef StringSet PredicateSet;
+typedef StringSet DecoderSet;
 struct DecoderTableInfo {
   DecoderTable Table;
   FixupScopeList FixupStack;