+#if defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7EM__) || defined(__ARM_ARCH_7S__)
+
+# define BOOST_SP_ARM_BARRIER "dmb"
+# define BOOST_SP_ARM_HAS_LDREX
+
+#elif defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__)
+
+# define BOOST_SP_ARM_BARRIER "mcr p15, 0, r0, c7, c10, 5"
+# define BOOST_SP_ARM_HAS_LDREX
+
+#else
+
+# define BOOST_SP_ARM_BARRIER ""
+
+#endif
+