diff --git a/include/common/compiler.h b/include/common/compiler.h
index b6f5af6..179b318 100644
--- a/include/common/compiler.h
+++ b/include/common/compiler.h
@@ -151,5 +151,36 @@
 #endif
 #endif
 
+/* Some architectures have a double-word CAS, sometimes even dual-8 bytes.
+ * Some architectures support unaligned accesses, others are fine with them
+ * but only for non-atomic operations. Also mention those supporting unaligned
+ * accesses and being little endian, and those where unaligned accesses are
+ * known to be fast (almost as fast as aligned ones).
+ */
+#if defined(__x86_64__)
+#define HA_UNALIGNED
+#define HA_UNALIGNED_LE
+#define HA_UNALIGNED_LE64
+#define HA_UNALIGNED_FAST
+#define HA_UNALIGNED_ATOMIC
+#define HA_HAVE_CAS_DW
+#define HA_CAS_IS_8B
+#elif defined(__i386__) || defined(__i486__) || defined(__i586__) || defined(__i686__)
+#define HA_UNALIGNED
+#define HA_UNALIGNED_LE
+#define HA_UNALIGNED_ATOMIC
+#elif defined (__aarch64__) || defined(__ARM_ARCH_8A)
+#define HA_UNALIGNED
+#define HA_UNALIGNED_LE
+#define HA_UNALIGNED_LE64
+#define HA_UNALIGNED_FAST
+#define HA_HAVE_CAS_DW
+#define HA_CAS_IS_8B
+#elif defined(__arm__) && (defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__))
+#define HA_UNALIGNED
+#define HA_UNALIGNED_LE
+#define HA_UNALIGNED_FAST
+#define HA_HAVE_CAS_DW
+#endif
 
 #endif /* _COMMON_COMPILER_H */
diff --git a/include/common/config.h b/include/common/config.h
index 55ecd59..16f47c9 100644
--- a/include/common/config.h
+++ b/include/common/config.h
@@ -40,14 +40,6 @@
 #define THREAD_LOCAL
 #endif
 
-/* Some architectures have a double-word CAS, sometimes even dual-8 bytes */
-#if defined(__x86_64__) || defined (__aarch64__)
-#define HA_HAVE_CAS_DW
-#define HA_CAS_IS_8B
-#elif defined(__arm__) && (defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__))
-#define HA_HAVE_CAS_DW
-#endif
-
 /* On architectures supporting threads and double-word CAS, we can implement
  * lock-less memory pools. This isn't supported for debugging modes however.
  */