Update comment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47002 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86Subtarget.h b/lib/Target/X86/X86Subtarget.h
index 789ea3e..e34d1f1 100644
--- a/lib/Target/X86/X86Subtarget.h
+++ b/lib/Target/X86/X86Subtarget.h
@@ -53,8 +53,8 @@
   ///
   PICStyle::Style PICStyle;
   
-  /// X86SSELevel - MMX, SSE1, SSE2, SSE3, SSSE3, or none supported.
-  ///
+  /// X86SSELevel - MMX, SSE1, SSE2, SSE3, SSSE3, SSE41, SSE42, or
+  /// none supported.
   X86SSEEnum X86SSELevel;
 
   /// X863DNowLevel - 3DNow or 3DNow Athlon, or none supported.