--- a/auto/cc/conf
+++ b/auto/cc/conf
@@ -104,7 +104,7 @@ else
 fi
 
 CFLAGS="$CFLAGS $NGX_CC_OPT"
-
+NGX_TEST_LD_OPT="$NGX_LD_OPT"
 
 if [ "$NGX_PLATFORM" != win32 ]; then
 
@@ -125,16 +125,21 @@ if [ "$NGX_PLATFORM" != win32 ]; then
         fi
     fi
 
-    ngx_feature="gcc variadic macros"
-    ngx_feature_name="NGX_HAVE_GCC_VARIADIC_MACROS"
+
+    ngx_feature="gcc builtin atomic operations"
+    ngx_feature_name=NGX_HAVE_GCC_ATOMIC
     ngx_feature_run=yes
-    ngx_feature_incs="#include <stdio.h>
-#define var(dummy, args...)  sprintf(args)"
+    ngx_feature_incs=
     ngx_feature_path=
     ngx_feature_libs=
-    ngx_feature_test="char  buf[30]; buf[0] = '0';
-                      var(0, buf, \"%d\", 1);
-                      if (buf[0] != '1') return 1"
+    ngx_feature_test="long  n = 0;
+                      if (!__sync_bool_compare_and_swap(&n, 0, 1))
+                          return 1;
+                      if (__sync_fetch_and_add(&n, 1) != 1)
+                          return 1;
+                      if (n != 2)
+                          return 1;
+                      __sync_synchronize();"
     . auto/feature
 
 
@@ -155,6 +160,19 @@ if [ "$NGX_PLATFORM" != win32 ]; then
      fi
 
 
+    ngx_feature="gcc variadic macros"
+    ngx_feature_name="NGX_HAVE_GCC_VARIADIC_MACROS"
+    ngx_feature_run=yes
+    ngx_feature_incs="#include <stdio.h>
+#define var(dummy, args...)  sprintf(args)"
+    ngx_feature_path=
+    ngx_feature_libs=
+    ngx_feature_test="char  buf[30]; buf[0] = '0';
+                      var(0, buf, \"%d\", 1);
+                      if (buf[0] != '1') return 1"
+    . auto/feature
+
+
 #    ngx_feature="inline"
 #    ngx_feature_name=
 #    ngx_feature_run=no