diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index 528f4a7..16c0c10 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -1168,6 +1168,130 @@
   // FIXME: Make this an enum and parse into the enum when set.
   std::string CPU;
 
+  /// \brief Enumeration of all of the X86 CPUs supported by Clang.
+  ///
+  /// Each enumeration represents a particular CPU supported by Clang. These
+  /// loosely correspond to the options passed to '-march' or '-mtune' flags.
+  enum CPUKind {
+    CK_Generic,
+
+    /// \name i386
+    /// i386-generation processors.
+    //@{
+    CK_i386,
+    //@}
+
+    /// \name i486
+    /// i486-generation processors.
+    //@{
+    CK_i486,
+    CK_WinChipC6,
+    CK_WinChip2,
+    CK_C3,
+    //@}
+
+    /// \name i586
+    /// i586-generation processors, P5 microarchitecture based.
+    //@{
+    CK_i586,
+    CK_Pentium,
+    CK_PentiumMMX,
+    //@}
+
+    /// \name i686
+    /// i686-generation processors, P6 / Pentium M microarchitecture based.
+    //@{
+    CK_i686,
+    CK_PentiumPro,
+    CK_Pentium2,
+    CK_Pentium3,
+    CK_Pentium3M,
+    CK_PentiumM,
+    CK_C3_2,
+
+    /// This enumerator is a bit odd, as GCC no longer accepts -march=yonah.
+    /// Clang however has some logic to suport this.
+    // FIXME: Warn, deprecate, and potentially remove this.
+    CK_Yonah,
+    //@}
+
+    /// \name Netburst
+    /// Netburt microarchitecture based processors.
+    //@{
+    CK_Pentium4,
+    CK_Pentium4M,
+    CK_Prescott,
+    CK_Nocona,
+    //@}
+
+    /// \name Core
+    /// Core microarchitecture based processors.
+    //@{
+    CK_Core2,
+
+    /// This enumerator, like \see CK_Yonah, is a bit odd. It is another
+    /// codename which GCC no longer accepts as an option to -march, but Clang
+    /// has some logic for recognizing it.
+    // FIXME: Warn, deprecate, and potentially remove this.
+    CK_Penryn,
+    //@}
+
+    /// \name Atom
+    /// Atom processors
+    //@{
+    CK_Atom,
+    //@}
+
+    /// \name Nehalem
+    /// Nehalem microarchitecture based processors.
+    //@{
+    CK_Corei7,
+    CK_Corei7AVX,
+    CK_Corei7AVXi,
+    //@}
+
+    /// \name K6
+    /// K6 architecture processors.
+    //@{
+    CK_K6,
+    CK_K6_2,
+    CK_K6_3,
+    //@}
+
+    /// \name K7
+    /// K7 architecture processors.
+    //@{
+    CK_Athlon,
+    CK_AthlonThunderbird,
+    CK_Athlon4,
+    CK_AthlonXP,
+    CK_AthlonMP,
+    //@}
+
+    /// \name K8
+    /// K8 architecture processors.
+    //@{
+    CK_Athlon64,
+    CK_Athlon64SSE3,
+    CK_AthlonFX,
+    CK_K8,
+    CK_K8SSE,
+    CK_Opteron,
+    CK_OpteronSSE3,
+
+    /// This specification is deprecated and will be removed in the future.
+    /// Users should prefer \see CK_K8.
+    // FIXME: Warn on this when the CPU is set to it.
+    CK_x86_64,
+    //@}
+
+    /// \name Geode
+    /// Geode processors.
+    //@{
+    CK_Geode
+    //@}
+  };
+
 public:
   X86TargetInfo(const std::string& triple)
     : TargetInfo(triple), SSELevel(NoSSE), MMX3DNowLevel(NoMMX3DNow),