1 AC_DEFUN([AX_C___SYNC_VAL_COMPARE_AND_SWAP], [
2 AC_MSG_CHECKING(for __sync_val_compare_and_swap)
3 AC_CACHE_VAL(ac_cv___sync_val_compare_and_swap, [
6 [int a; if (__sync_val_compare_and_swap(&a, 0, 1)) return 1; return 0;],
7 ac_cv___sync_val_compare_and_swap=yes,
8 ac_cv___sync_val_compare_and_swap=no
10 if test "$ac_cv___sync_val_compare_and_swap" = "yes"; then
11 AC_DEFINE(HAVE___SYNC_VAL_COMPARE_AND_SWAP, 1, [define if your compiler has __sync_val_compare_and_swap])
13 AC_MSG_RESULT($ac_cv___sync_val_compare_and_swap)