Index: libowfat-0.29/CAS.h
===================================================================
--- libowfat-0.29.orig/CAS.h	2012-08-17 20:31:21.000000000 -0500
+++ libowfat-0.29/CAS.h	2014-02-10 22:37:16.059926666 -0600
@@ -53,7 +53,7 @@
 /* *x += val; */
 static inline void atomic_add(size_t* x,size_t val) {
 #ifdef USE_BUILTINS
-  return __sync_add_and_fetch(x,val);
+  __sync_add_and_fetch(x,val);
 #elif defined(__i386__)
   asm volatile ("lock; addl %1, %0" : "+m" (*x) : "ir" (val) );
 #elif defined(__x86_64__)