Use std::bitset for SubtargetFeatures

Previously, subtarget features were a bitfield with the underlying type being uint64_t. 
Since several targets (X86 and ARM, in particular) have hit or were very close to hitting this bound, switching the features to use a bitset.
No functional change.

The first time this was committed (r229831), it caused several buildbot failures. 
At least some of the ARM ones were due to gcc/binutils issues, and should now be fixed.

Differential Revision: http://reviews.llvm.org/D8542

llvm-svn: 233055

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
index 9b98a3e40d4..7124501f979 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
@@ -42,15 +42,15 @@ public:
   ~X86MCCodeEmitter() {}
 
   bool is64BitMode(const MCSubtargetInfo &STI) const {
-    return (STI.getFeatureBits() & X86::Mode64Bit) != 0;
+    return STI.getFeatureBits()[X86::Mode64Bit];
   }
 
   bool is32BitMode(const MCSubtargetInfo &STI) const {
-    return (STI.getFeatureBits() & X86::Mode32Bit) != 0;
+    return STI.getFeatureBits()[X86::Mode32Bit];
   }
 
   bool is16BitMode(const MCSubtargetInfo &STI) const {
-    return (STI.getFeatureBits() & X86::Mode16Bit) != 0;
+    return STI.getFeatureBits()[X86::Mode16Bit];
   }
 
   /// Is16BitMemOperand - Return true if the specified instruction has