$OpenBSD: patch-src_pl-wam_c,v 1.1 2011/09/07 11:25:18 naddy Exp $
--- src/pl-wam.c.orig	Wed Sep  7 00:30:34 2011
+++ src/pl-wam.c	Wed Sep  7 00:42:47 2011
@@ -790,7 +790,8 @@ MSB(unsigned int i)
 #define MemoryBarrier() (void)0
 #endif
 
-#elif defined(__GNUC__)			/* GCC version */
+#elif defined(__GNUC__) && \
+  (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ > 3)	/* GCC version */
 
 #define MSB(i) (31 - __builtin_clz(i))
 #define MemoryBarrier() __sync_synchronize()
