Index: lib/Headers/armintr.h
===================================================================
--- lib/Headers/armintr.h
+++ lib/Headers/armintr.h
@@ -41,5 +41,21 @@
   _ARM_BARRIER_OSHST = 0x2
 } _ARMINTR_BARRIER_TYPE;
 
+typedef enum
+{
+  _ARM64_BARRIER_SY    = 0xF,
+  _ARM64_BARRIER_ST    = 0xE,
+  _ARM64_BARRIER_LD    = 0xD,
+  _ARM64_BARRIER_ISH   = 0xB,
+  _ARM64_BARRIER_ISHST = 0xA,
+  _ARM64_BARRIER_ISHLD = 0x9,
+  _ARM64_BARRIER_NSH   = 0x7,
+  _ARM64_BARRIER_NSHST = 0x6,
+  _ARM64_BARRIER_NSHLD = 0x5,
+  _ARM64_BARRIER_OSH   = 0x3,
+  _ARM64_BARRIER_OSHST = 0x2,
+  _ARM64_BARRIER_OSHLD = 0x1
+} _ARM64INTR_BARRIER_TYPE;
+
 #endif /* __ARMINTR_H */
 #endif /* _MSC_VER */