1 dnl ### A macro to determine endianness of long long 2 AC_DEFUN([AC_LITTLE_ENDIAN_LONG_LONG], 3 [AC_MSG_CHECKING(for little endian long long) 4 AC_CACHE_VAL(ac_cv_have_little_endian_long_long, 5 [AC_RUN_IFELSE([AC_LANG_SOURCE([[ 6 int main () { 7 union { 8 long long ll; 9 int l [2]; 10 } u; 11 u.ll = 0x12345678; 12 if (u.l[0] == 0x12345678) 13 return 0; 14 return 1; 15 } 16 ]])],[ac_cv_have_little_endian_long_long=yes],[ac_cv_have_little_endian_long_long=no],[ 17 if test "x$ac_cv_c_bigendian" = "xyes"; then 18 ac_cv_have_little_endian_long_long=no 19 else 20 ac_cv_have_little_endian_long_long=yes 21 fi 22 ])]) 23 AC_MSG_RESULT($ac_cv_have_little_endian_long_long) 24 if test "$ac_cv_have_little_endian_long_long" = yes 25 then 26 AC_DEFINE([HAVE_LITTLE_ENDIAN_LONG_LONG], 1, 27 [Define if long long is little-endian.]) 28 fi 29 ]) 30
