--- radeon_cs_gem.c.orig	2014-11-28 13:44:09.000000000 -0500
+++ radeon_cs_gem.c	2014-11-29 20:38:14.000000000 -0500
@@ -78,14 +78,30 @@
 static pthread_mutex_t id_mutex = PTHREAD_MUTEX_INITIALIZER;
 static uint32_t cs_id_source = 0;
 
+#if __GNUC__*100000+__GNUC_MINOR__*1000+__GNUC_PATCHLEVEL__ >= 304060
 /**
  * result is undefined if called with ~0
  */
+/* __builtin_ctz returns number of trailing zeros, only gcc >= 3.4.6 */
 static uint32_t get_first_zero(const uint32_t n)
 {
-    /* __builtin_ctz returns number of trailing zeros. */
     return 1 << __builtin_ctz(~n);
 }
+#else
+/* in: ~1110,0001,trailing0==0,1<<0 out: 0001 */
+#include <limits.h>
+static uint32_t get_first_zero(const uint32_t n)
+{
+    uint32_t nn, i;
+    nn=n;
+    for(i=0;i<=sizeof(n)*CHAR_BIT-1;++i)
+    {
+        if(!(nn & 1)) return (uint32_t) 1<<i;
+        nn=nn>>1;
+    }
+    return (uint32_t) 0;
+}
+#endif
 
 /**
  * Returns a free id for cs.