+
+dnl AC_LIB_PREPARE_MULTILIB creates a variable acl_libdirstem, containing
+dnl the basename of the libdir, either "lib" or "lib64".
+AC_DEFUN([AC_LIB_PREPARE_MULTILIB],
+[
+ dnl There is no formal standard regarding lib and lib64. The current
+ dnl practice is that on a system supporting 32-bit and 64-bit instruction
+ dnl sets or ABIs, 64-bit libraries go under $prefix/lib64 and 32-bit
+ dnl libraries go under $prefix/lib. We determine the compiler's default
+ dnl mode by looking at the compiler's library search path. If at least
+ dnl of its elements ends in /lib64 or points to a directory whose absolute
+ dnl pathname ends in /lib64, we assume a 64-bit ABI. Otherwise we use the
+ dnl default, namely "lib".
+ acl_libdirstem=lib
+ searchpath=`(LC_ALL=C $CC -print-search-dirs) 2>/dev/null | sed -n -e 's,^libraries: ,,p' | sed -e 's,^=,,'`
+ if test -n "$searchpath"; then
+ acl_save_IFS="${IFS= }"; IFS=":"
+ for searchdir in $searchpath; do
+ if test -d "$searchdir"; then
+ case "$searchdir" in
+ */lib64/ | */lib64 ) acl_libdirstem=lib64 ;;
+ *) searchdir=`cd "$searchdir" && pwd`
+ case "$searchdir" in
+ */lib64 ) acl_libdirstem=lib64 ;;
+ esac ;;
+ esac
+ fi
+ done
+ IFS="$acl_save_IFS"
+ fi
+])