1 AC_DEFUN([OPENAFS_C_ATOMIC_CHECKS], [
2 AC_CACHE_CHECK([if compiler has __sync_add_and_fetch],
3 [ac_cv_sync_fetch_and_add],
4 [AC_TRY_LINK(, [int var; return __sync_add_and_fetch(&var, 1);],
5 [ac_cv_sync_fetch_and_add=yes],
6 [ac_cv_sync_fetch_and_add=no])
8 AS_IF([test "$ac_cv_sync_fetch_and_add" = "yes"],
9 [AC_DEFINE(HAVE_SYNC_FETCH_AND_ADD, 1,
10 [define if your C compiler has __sync_add_and_fetch])])