diff --git a/include/llvm/Target/SubtargetFeature.h b/include/llvm/Target/SubtargetFeature.h
index 6c21ae9583e..4213d9b12ed 100644
--- a/include/llvm/Target/SubtargetFeature.h
+++ b/include/llvm/Target/SubtargetFeature.h
@@ -35,8 +35,8 @@ namespace llvm {
 struct SubtargetFeatureKV {
   const char *Key;                      // K-V key string
   const char *Desc;                     // Help descriptor
-  uint32_t Value;                       // K-V integer value
-  uint32_t Implies;                     // K-V bit mask
+  uint64_t Value;                       // K-V integer value
+  uint64_t Implies;                     // K-V bit mask
   
   // Compare routine for std binary search
   bool operator<(const SubtargetFeatureKV &S) const {
@@ -94,7 +94,7 @@ public:
   void AddFeature(const std::string &String, bool IsEnabled = true);
            
   /// Get feature bits.
-  uint32_t getBits(const SubtargetFeatureKV *CPUTable,
+  uint64_t getBits(const SubtargetFeatureKV *CPUTable,
                          size_t CPUTableSize,
                    const SubtargetFeatureKV *FeatureTable,
                          size_t FeatureTableSize);
diff --git a/lib/Target/SubtargetFeature.cpp b/lib/Target/SubtargetFeature.cpp
index 3cf95b57c5d..e0a9de82983 100644
--- a/lib/Target/SubtargetFeature.cpp
+++ b/lib/Target/SubtargetFeature.cpp
@@ -211,7 +211,7 @@ const std::string & SubtargetFeatures::getCPU() const {
 /// feature, set it.
 ///
 static
-void SetImpliedBits(uint32_t &Bits, const SubtargetFeatureKV *FeatureEntry,
+void SetImpliedBits(uint64_t &Bits, const SubtargetFeatureKV *FeatureEntry,
                     const SubtargetFeatureKV *FeatureTable,
                     size_t FeatureTableSize) {
   for (size_t i = 0; i < FeatureTableSize; ++i) {
@@ -230,7 +230,7 @@ void SetImpliedBits(uint32_t &Bits, const SubtargetFeatureKV *FeatureEntry,
 /// feature, clear it.
 /// 
 static
-void ClearImpliedBits(uint32_t &Bits, const SubtargetFeatureKV *FeatureEntry,
+void ClearImpliedBits(uint64_t &Bits, const SubtargetFeatureKV *FeatureEntry,
                       const SubtargetFeatureKV *FeatureTable,
                       size_t FeatureTableSize) {
   for (size_t i = 0; i < FeatureTableSize; ++i) {
@@ -247,7 +247,7 @@ void ClearImpliedBits(uint32_t &Bits, const SubtargetFeatureKV *FeatureEntry,
 
 /// getBits - Get feature bits.
 ///
-uint32_t SubtargetFeatures::getBits(const SubtargetFeatureKV *CPUTable,
+uint64_t SubtargetFeatures::getBits(const SubtargetFeatureKV *CPUTable,
                                           size_t CPUTableSize,
                                     const SubtargetFeatureKV *FeatureTable,
                                           size_t FeatureTableSize) {
@@ -263,7 +263,7 @@ uint32_t SubtargetFeatures::getBits(const SubtargetFeatureKV *CPUTable,
           "CPU features table is not sorted");
   }
 #endif
-  uint32_t Bits = 0;                    // Resulting bits
+  uint64_t Bits = 0;                    // Resulting bits
 
   // Check if help is needed
   if (Features[0] == "help")
diff --git a/utils/TableGen/SubtargetEmitter.cpp b/utils/TableGen/SubtargetEmitter.cpp
index 8ca4b1c1446..928fa4bee90 100644
--- a/utils/TableGen/SubtargetEmitter.cpp
+++ b/utils/TableGen/SubtargetEmitter.cpp
@@ -33,7 +33,13 @@ void SubtargetEmitter::Enumeration(raw_ostream &OS,
   OS << "enum {\n";
 
   // For each record
-  for (unsigned i = 0, N = DefList.size(); i < N;) {
+  unsigned N = DefList.size();
+  if (N > 64) {
+    errs() << "Too many (> 64) subtarget features!\n";
+    exit(1);
+  }
+
+  for (unsigned i = 0; i < N;) {
     // Next record
     Record *Def = DefList[i];
 
@@ -41,7 +47,7 @@ void SubtargetEmitter::Enumeration(raw_ostream &OS,
     OS << "  " << Def->getName();
 
     // If bit flags then emit expression (1 << i)
-    if (isBits)  OS << " = " << " 1 << " << i;
+    if (isBits)  OS << " = " << " 1ULL << " << i;
 
     // Depending on 'if more in the list' emit comma
     if (++i < N) OS << ",";
@@ -88,7 +94,7 @@ void SubtargetEmitter::FeatureKeyValues(raw_ostream &OS) {
       Feature->getValueAsListOfDefs("Implies");
 
     if (ImpliesList.empty()) {
-      OS << "0";
+      OS << "0ULL";
     } else {
       for (unsigned j = 0, M = ImpliesList.size(); j < M;) {
         OS << ImpliesList[j]->getName();
@@ -142,7 +148,7 @@ void SubtargetEmitter::CPUKeyValues(raw_ostream &OS) {
        << "\"Select the " << Name << " processor\", ";
 
     if (FeatureList.empty()) {
-      OS << "0";
+      OS << "0ULL";
     } else {
       for (unsigned j = 0, M = FeatureList.size(); j < M;) {
         OS << FeatureList[j]->getName();
@@ -151,7 +157,7 @@ void SubtargetEmitter::CPUKeyValues(raw_ostream &OS) {
     }
 
     // The "0" is for the "implies" section of this data structure.
-    OS << ", 0 }";
+    OS << ", 0ULL }";
 
     // Depending on 'if more in the list' emit comma
     if (++i < N) OS << ",";
@@ -608,7 +614,7 @@ void SubtargetEmitter::ParseFeaturesFunction(raw_ostream &OS) {
      << "  DEBUG(dbgs() << \"\\nCPU:\" << CPU);\n"
      << "  SubtargetFeatures Features(FS);\n"
      << "  Features.setCPUIfNone(CPU);\n"
-     << "  uint32_t Bits =  Features.getBits(SubTypeKV, SubTypeKVSize,\n"
+     << "  uint64_t Bits =  Features.getBits(SubTypeKV, SubTypeKVSize,\n"
      << "                                    FeatureKV, FeatureKVSize);\n";
 
   for (unsigned i = 0; i < Features.size(); i++) {