--- a/src/os/unix/ngx_atomic.h
+++ b/src/os/unix/ngx_atomic.h
@@ -60,10 +60,40 @@ typedef uint32_t                    ngx_
 typedef volatile ngx_atomic_uint_t  ngx_atomic_t;
 
 
-#else /* !(NGX_DARWIN) */
+#elif (NGX_HAVE_GCC_ATOMIC)
+
+/* GCC 4.1 builtin atomic operations */
+
+#define NGX_HAVE_ATOMIC_OPS  1
+
+typedef long                        ngx_atomic_int_t;
+typedef unsigned long               ngx_atomic_uint_t;
+
+#if (NGX_PTR_SIZE == 8)
+#define NGX_ATOMIC_T_LEN            (sizeof("-9223372036854775808") - 1)
+#else
+#define NGX_ATOMIC_T_LEN            (sizeof("-2147483648") - 1)
+#endif
+
+typedef volatile ngx_atomic_uint_t  ngx_atomic_t;
 
 
-#if ( __i386__ || __i386 )
+#define ngx_atomic_cmp_set(lock, old, set)                                    \
+    __sync_bool_compare_and_swap(lock, old, set)
+
+#define ngx_atomic_fetch_add(value, add)                                      \
+    __sync_fetch_and_add(value, add)
+
+#define ngx_memory_barrier()        __sync_synchronize()
+
+#if ( __i386__ || __i386 || __amd64__ || __amd64 )
+#define ngx_cpu_pause()             __asm__ ("pause")
+#else
+#define ngx_cpu_pause()
+#endif
+
+
+#elif ( __i386__ || __i386 )
 
 typedef int32_t                     ngx_atomic_int_t;
 typedef uint32_t                    ngx_atomic_uint_t;
@@ -203,9 +233,6 @@ typedef volatile ngx_atomic_uint_t  ngx_
 
 #include "ngx_gcc_atomic_ppc.h"
 
-
-#endif
-
 #endif