Index: apr/atomic/unix/builtins.c
===================================================================
--- /dev/null
+++ apr/atomic/unix/builtins.c
@@ -0,0 +1,74 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "apr_arch_atomic.h"
+
+#ifdef USE_ATOMICS_BUILTINS
+
+APR_DECLARE(apr_status_t) apr_atomic_init(apr_pool_t *p)
+{
+    return APR_SUCCESS;
+}
+
+APR_DECLARE(apr_uint32_t) apr_atomic_read32(volatile apr_uint32_t *mem)
+{
+    return *mem;
+}
+
+APR_DECLARE(void) apr_atomic_set32(volatile apr_uint32_t *mem, apr_uint32_t val)
+{
+    *mem = val;
+}
+
+APR_DECLARE(apr_uint32_t) apr_atomic_add32(volatile apr_uint32_t *mem, apr_uint32_t val)
+{
+    return __sync_fetch_and_add(mem, val);
+}
+
+APR_DECLARE(void) apr_atomic_sub32(volatile apr_uint32_t *mem, apr_uint32_t val)
+{
+    __sync_fetch_and_sub(mem, val);
+}
+
+APR_DECLARE(apr_uint32_t) apr_atomic_inc32(volatile apr_uint32_t *mem)
+{
+    return __sync_fetch_and_add(mem, 1);
+}
+
+APR_DECLARE(int) apr_atomic_dec32(volatile apr_uint32_t *mem)
+{
+    return __sync_sub_and_fetch(mem, 1);
+}
+
+APR_DECLARE(apr_uint32_t) apr_atomic_cas32(volatile apr_uint32_t *mem, apr_uint32_t with,
+                                           apr_uint32_t cmp)
+{
+    return __sync_val_compare_and_swap(mem, cmp, with);
+}
+
+APR_DECLARE(apr_uint32_t) apr_atomic_xchg32(volatile apr_uint32_t *mem, apr_uint32_t val)
+{
+    __sync_synchronize();
+
+    return __sync_lock_test_and_set(mem, val);
+}
+
+APR_DECLARE(void*) apr_atomic_casptr(volatile void **mem, void *with, const void *cmp)
+{
+    return (void*) __sync_val_compare_and_swap(mem, cmp, with);
+}
+
+#endif /* USE_ATOMICS_BUILTINS */
Index: apr/configure.in
===================================================================
--- apr.orig/configure.in
+++ apr/configure.in
@@ -350,6 +350,48 @@ case "$host:$CC" in
 	;;
 esac
 
+AC_CACHE_CHECK([whether the compiler provides atomic builtins], [atomic_builtins],
+[AC_TRY_RUN([
+int main()
+{
+    unsigned long val = 1010, tmp, *mem = &val;
+
+    if (__sync_fetch_and_add(&val, 1010) != 1010 || val != 2020)
+        return 1;
+
+    tmp = val;
+
+    if (__sync_fetch_and_sub(mem, 1010) != tmp || val != 1010)
+        return 1;
+
+    if (__sync_sub_and_fetch(&val, 1010) != 0 || val != 0)
+        return 1;
+
+    tmp = 3030;
+
+    if (__sync_val_compare_and_swap(mem, 0, tmp) != 0 || val != tmp)
+        return 1;
+
+    if (__sync_lock_test_and_set(&val, 4040) != 3030)
+        return 1;
+
+    mem = &tmp;
+
+    if (__sync_val_compare_and_swap(&mem, &tmp, &val) != &tmp)
+        return 1;
+
+    __sync_synchronize();
+
+    if (mem != &val)
+        return 1;
+
+    return 0;
+}], [atomic_builtins=yes], [atomic_builtins=no], [atomic_builtins=no])])
+
+if test "$atomic_builtins" = "yes"; then
+    AC_DEFINE(HAVE_ATOMIC_BUILTINS, 1, [Define if compiler provides atomic builtins])
+fi
+
 dnl Check the depend program we can use
 APR_CHECK_DEPEND
 
Index: apr/include/arch/unix/apr_arch_atomic.h
===================================================================
--- apr.orig/include/arch/unix/apr_arch_atomic.h
+++ apr/include/arch/unix/apr_arch_atomic.h
@@ -28,6 +28,8 @@
 /* force use of generic atomics if building e.g. with -std=c89, which
  * doesn't allow inline asm */
 #   define USE_ATOMICS_GENERIC
+#elif HAVE_ATOMIC_BUILTINS
+#   define USE_ATOMICS_BUILTINS
 #else
 #   define USE_ATOMICS_GENERIC
 #endif