Index: llvm/trunk/include/llvm/MC/SubtargetFeature.h
===================================================================
--- llvm/trunk/include/llvm/MC/SubtargetFeature.h
+++ llvm/trunk/include/llvm/MC/SubtargetFeature.h
@@ -18,6 +18,7 @@
 #define LLVM_MC_SUBTARGETFEATURE_H
 
 #include "llvm/ADT/StringRef.h"
+#include <array>
 #include <bitset>
 #include <initializer_list>
 #include <string>
@@ -29,7 +30,9 @@
 class raw_ostream;
 class Triple;
 
-const unsigned MAX_SUBTARGET_FEATURES = 192;
+const unsigned MAX_SUBTARGET_WORDS = 3;
+const unsigned MAX_SUBTARGET_FEATURES = MAX_SUBTARGET_WORDS * 64;
+
 /// Container class for subtarget features.
 /// This is convenient because std::bitset does not have a constructor
 /// with an initializer list of set bits.
@@ -46,6 +49,26 @@
   }
 };
 
+/// Class used to store the subtarget bits in the tables created by tablegen.
+/// The std::initializer_list constructor of FeatureBitset can't be done at
+/// compile time and requires a static constructor to run at startup.
+class FeatureBitArray {
+  std::array<uint64_t, MAX_SUBTARGET_WORDS> Bits;
+
+public:
+  constexpr FeatureBitArray(const std::array<uint64_t, MAX_SUBTARGET_WORDS> &B)
+      : Bits(B) {}
+
+  FeatureBitset getAsBitset() const {
+    FeatureBitset Result;
+
+    for (unsigned i = 0, e = Bits.size(); i != e; ++i)
+      Result |= FeatureBitset(Bits[i]) << (64 * i);
+
+    return Result;
+  }
+};
+
 //===----------------------------------------------------------------------===//
 
 /// Used to provide key value pairs for feature and CPU bit flags.
@@ -53,7 +76,7 @@
   const char *Key;                      ///< K-V key string
   const char *Desc;                     ///< Help descriptor
   unsigned Value;                       ///< K-V integer value
-  FeatureBitset Implies;                ///< K-V bit mask
+  FeatureBitArray Implies;              ///< K-V bit mask
 
   /// Compare routine for std::lower_bound
   bool operator<(StringRef S) const {
Index: llvm/trunk/lib/MC/SubtargetFeature.cpp
===================================================================
--- llvm/trunk/lib/MC/SubtargetFeature.cpp
+++ llvm/trunk/lib/MC/SubtargetFeature.cpp
@@ -122,29 +122,24 @@
 
 /// For each feature that is (transitively) implied by this feature, set it.
 static
-void SetImpliedBits(FeatureBitset &Bits, const SubtargetFeatureKV &FeatureEntry,
+void SetImpliedBits(FeatureBitset &Bits, const FeatureBitset &Implies,
                     ArrayRef<SubtargetFeatureKV> FeatureTable) {
   for (const SubtargetFeatureKV &FE : FeatureTable) {
-    if (FeatureEntry.Value == FE.Value) continue;
-
-    if (FeatureEntry.Implies.test(FE.Value)) {
+    if (Implies.test(FE.Value)) {
       Bits.set(FE.Value);
-      SetImpliedBits(Bits, FE, FeatureTable);
+      SetImpliedBits(Bits, FE.Implies.getAsBitset(), FeatureTable);
     }
   }
 }
 
 /// For each feature that (transitively) implies this feature, clear it.
 static
-void ClearImpliedBits(FeatureBitset &Bits,
-                      const SubtargetFeatureKV &FeatureEntry,
+void ClearImpliedBits(FeatureBitset &Bits, unsigned Value,
                       ArrayRef<SubtargetFeatureKV> FeatureTable) {
   for (const SubtargetFeatureKV &FE : FeatureTable) {
-    if (FeatureEntry.Value == FE.Value) continue;
-
-    if (FE.Implies.test(FeatureEntry.Value)) {
+    if (FE.Implies.getAsBitset().test(Value)) {
       Bits.reset(FE.Value);
-      ClearImpliedBits(Bits, FE, FeatureTable);
+      ClearImpliedBits(Bits, FE.Value, FeatureTable);
     }
   }
 }
@@ -160,12 +155,12 @@
     if (Bits.test(FeatureEntry->Value)) {
       Bits.reset(FeatureEntry->Value);
       // For each feature that implies this, clear it.
-      ClearImpliedBits(Bits, *FeatureEntry, FeatureTable);
+      ClearImpliedBits(Bits, FeatureEntry->Value, FeatureTable);
     } else {
       Bits.set(FeatureEntry->Value);
 
       // For each feature that this implies, set it.
-      SetImpliedBits(Bits, *FeatureEntry, FeatureTable);
+      SetImpliedBits(Bits, FeatureEntry->Implies.getAsBitset(), FeatureTable);
     }
   } else {
     errs() << "'" << Feature << "' is not a recognized feature for this target"
@@ -187,12 +182,12 @@
       Bits.set(FeatureEntry->Value);
 
       // For each feature that this implies, set it.
-      SetImpliedBits(Bits, *FeatureEntry, FeatureTable);
+      SetImpliedBits(Bits, FeatureEntry->Implies.getAsBitset(), FeatureTable);
     } else {
       Bits.reset(FeatureEntry->Value);
 
       // For each feature that implies this, clear it.
-      ClearImpliedBits(Bits, *FeatureEntry, FeatureTable);
+      ClearImpliedBits(Bits, FeatureEntry->Value, FeatureTable);
     }
   } else {
     errs() << "'" << Feature << "' is not a recognized feature for this target"
@@ -225,12 +220,13 @@
     // If there is a match
     if (CPUEntry) {
       // Set base feature bits
-      Bits = CPUEntry->Implies;
+      FeatureBitset CPUImplies = CPUEntry->Implies.getAsBitset();
+      Bits = CPUImplies;
 
       // Set the feature implied by this CPU feature, if any.
       for (auto &FE : FeatureTable) {
-        if (CPUEntry->Implies.test(FE.Value))
-          SetImpliedBits(Bits, FE, FeatureTable);
+        if (CPUImplies.test(FE.Value))
+          SetImpliedBits(Bits, FE.Implies.getAsBitset(), FeatureTable);
       }
     } else {
       errs() << "'" << CPU << "' is not a recognized processor for this target"
Index: llvm/trunk/utils/TableGen/SubtargetEmitter.cpp
===================================================================
--- llvm/trunk/utils/TableGen/SubtargetEmitter.cpp
+++ llvm/trunk/utils/TableGen/SubtargetEmitter.cpp
@@ -73,9 +73,11 @@
   CodeGenSchedModels &SchedModels;
   std::string Target;
 
-  void Enumeration(raw_ostream &OS);
-  unsigned FeatureKeyValues(raw_ostream &OS);
-  unsigned CPUKeyValues(raw_ostream &OS);
+  void Enumeration(raw_ostream &OS, DenseMap<Record *, unsigned> &FeatureMap);
+  unsigned FeatureKeyValues(raw_ostream &OS,
+                            const DenseMap<Record *, unsigned> &FeatureMap);
+  unsigned CPUKeyValues(raw_ostream &OS,
+                        const DenseMap<Record *, unsigned> &FeatureMap);
   void FormItineraryStageString(const std::string &Names,
                                 Record *ItinData, std::string &ItinString,
                                 unsigned &NStages);
@@ -137,7 +139,8 @@
 //
 // Enumeration - Emit the specified class as an enumeration.
 //
-void SubtargetEmitter::Enumeration(raw_ostream &OS) {
+void SubtargetEmitter::Enumeration(raw_ostream &OS,
+                                   DenseMap<Record *, unsigned> &FeatureMap) {
   // Get all records of class and sort
   std::vector<Record*> DefList =
     Records.getAllDerivedDefinitions("SubtargetFeature");
@@ -161,6 +164,9 @@
 
     // Get and emit name
     OS << "  " << Def->getName() << " = " << i << ",\n";
+
+    // Save the index for this feature.
+    FeatureMap[Def] = i;
   }
 
   // Close enumeration and namespace
@@ -168,11 +174,29 @@
   OS << "} // end namespace " << Target << "\n";
 }
 
+static void printFeatureMask(raw_ostream &OS, RecVec &FeatureList,
+                             const DenseMap<Record *, unsigned> &FeatureMap) {
+  std::array<uint64_t, MAX_SUBTARGET_WORDS> Mask = {};
+  for (unsigned j = 0, M = FeatureList.size(); j < M; ++j) {
+    unsigned Bit = FeatureMap.lookup(FeatureList[j]);
+    Mask[Bit / 64] |= 1ULL << (Bit % 64);
+  }
+
+  OS << "{ { ";
+  for (unsigned i = 0; i != Mask.size(); ++i) {
+    OS << "0x";
+    OS.write_hex(Mask[i]);
+    OS << "ULL, ";
+  }
+  OS << "} }";
+}
+
 //
 // FeatureKeyValues - Emit data of all the subtarget features.  Used by the
 // command line.
 //
-unsigned SubtargetEmitter::FeatureKeyValues(raw_ostream &OS) {
+unsigned SubtargetEmitter::FeatureKeyValues(
+    raw_ostream &OS, const DenseMap<Record *, unsigned> &FeatureMap) {
   // Gather and sort all the features
   std::vector<Record*> FeatureList =
                            Records.getAllDerivedDefinitions("SubtargetFeature");
@@ -207,12 +231,9 @@
 
     RecVec ImpliesList = Feature->getValueAsListOfDefs("Implies");
 
-    OS << "{";
-    for (unsigned j = 0, M = ImpliesList.size(); j < M;) {
-      OS << " " << Target << "::" << ImpliesList[j]->getName();
-      if (++j < M) OS << ",";
-    }
-    OS << " } },\n";
+    printFeatureMask(OS, ImpliesList, FeatureMap);
+
+    OS << " },\n";
     ++NumFeatures;
   }
 
@@ -226,7 +247,9 @@
 // CPUKeyValues - Emit data of all the subtarget processors.  Used by command
 // line.
 //
-unsigned SubtargetEmitter::CPUKeyValues(raw_ostream &OS) {
+unsigned
+SubtargetEmitter::CPUKeyValues(raw_ostream &OS,
+                               const DenseMap<Record *, unsigned> &FeatureMap) {
   // Gather and sort processor information
   std::vector<Record*> ProcessorList =
                           Records.getAllDerivedDefinitions("Processor");
@@ -248,12 +271,10 @@
        << "\"" << Name << "\", "
        << "\"Select the " << Name << " processor\", 0, ";
 
-    OS << "{";
-    for (unsigned j = 0, M = FeatureList.size(); j < M;) {
-      OS << " " << Target << "::" << FeatureList[j]->getName();
-      if (++j < M) OS << ",";
-    }
-    OS << " } },\n";
+    printFeatureMask(OS, FeatureList, FeatureMap);
+
+    // The {{}} is for the "implies" section of this data structure.
+    OS << " },\n";
   }
 
   // End processor table
@@ -1789,8 +1810,10 @@
   OS << "\n#ifdef GET_SUBTARGETINFO_ENUM\n";
   OS << "#undef GET_SUBTARGETINFO_ENUM\n\n";
 
+  DenseMap<Record *, unsigned> FeatureMap;
+
   OS << "namespace llvm {\n";
-  Enumeration(OS);
+  Enumeration(OS, FeatureMap);
   OS << "} // end namespace llvm\n\n";
   OS << "#endif // GET_SUBTARGETINFO_ENUM\n\n";
 
@@ -1801,9 +1824,9 @@
 #if 0
   OS << "namespace {\n";
 #endif
-  unsigned NumFeatures = FeatureKeyValues(OS);
+  unsigned NumFeatures = FeatureKeyValues(OS, FeatureMap);
   OS << "\n";
-  unsigned NumProcs = CPUKeyValues(OS);
+  unsigned NumProcs = CPUKeyValues(OS, FeatureMap);
   OS << "\n";
   EmitSchedModel(OS);
   OS << "\n";