1 files changed, 23 insertions, 5 deletions
diff --git a/include/llvm/MC/SubtargetFeature.h b/include/llvm/MC/SubtargetFeature.h
index bfecb8ba6ab0a..6a631ffe79bd3 100644
--- a/include/llvm/MC/SubtargetFeature.h
+++ b/include/llvm/MC/SubtargetFeature.h
@@ -21,11 +21,29 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/Support/DataTypes.h"
+#include <bitset>
 
 namespace llvm {
   class raw_ostream;
   class StringRef;
 
+// A container class for subtarget features.
+// This is convenient because std::bitset does not have a constructor
+// with an initializer list of set bits.
+const unsigned MAX_SUBTARGET_FEATURES = 64;
+class FeatureBitset : public std::bitset<MAX_SUBTARGET_FEATURES> {
+public:
+  // Cannot inherit constructors because it's not supported by VC++..
+  FeatureBitset() : bitset() {}
+
+  FeatureBitset(const bitset<MAX_SUBTARGET_FEATURES>& B) : bitset(B) {}
+
+  FeatureBitset(std::initializer_list<unsigned> Init) : bitset() {
+    for (auto I = Init.begin() , E = Init.end(); I != E; ++I)
+      set(*I);
+  }
+};
+
 //===----------------------------------------------------------------------===//
 ///
 /// SubtargetFeatureKV - Used to provide key value pairs for feature and
@@ -34,8 +52,8 @@ namespace llvm {
 struct SubtargetFeatureKV {
   const char *Key;                      // K-V key string
   const char *Desc;                     // Help descriptor
-  uint64_t Value;                       // K-V integer value
-  uint64_t Implies;                     // K-V bit mask
+  FeatureBitset Value;                  // K-V integer value
+  FeatureBitset Implies;                // K-V bit mask
 
   // Compare routine for std::lower_bound
   bool operator<(StringRef S) const {
@@ -78,15 +96,15 @@ public:
   std::string getString() const;
 
   /// Adding Features.
-  void AddFeature(StringRef String);
+  void AddFeature(StringRef String, bool Enable = true);
 
   /// ToggleFeature - Toggle a feature and returns the newly updated feature
   /// bits.
-  uint64_t ToggleFeature(uint64_t Bits, StringRef String,
+  FeatureBitset ToggleFeature(FeatureBitset Bits, StringRef String,
                          ArrayRef<SubtargetFeatureKV> FeatureTable);
 
   /// Get feature bits of a CPU.
-  uint64_t getFeatureBits(StringRef CPU,
+  FeatureBitset getFeatureBits(StringRef CPU,
                           ArrayRef<SubtargetFeatureKV> CPUTable,
                           ArrayRef<SubtargetFeatureKV> FeatureTable);