+# Check for various supplementary host information (beyond the
+# triplet) which might affect the library format choices. E.g., we
+# can be building with `i686-unknown-linux-gnu-gcc -m64'
+
+case "${host}" in
+changequote(,)dnl
+ i[34567]86-*-linux*)
+changequote([,])dnl
+ AC_CACHE_CHECK([if building for x86-64], [ust_cv_i386_is_x86_64],
+ [save_CPPFLAGS="$CPPFLAGS"
+ CPPFLAGS="$CPPFLAGS $CFLAGS"
+ AC_EGREP_CPP([got it], [
+#if __x86_64__
+got it
+#endif
+ ], [ust_cv_i386_is_x86_64=yes],
+ [ust_cv_i386_is_x86_64=no])
+ CPPFLAGS="$save_CPPFLAGS"])
+ ;;
+esac
+
+AC_MSG_CHECKING([library format for the host system])
+case $host_cpu in
+changequote(,)dnl
+ i[3456]86)
+changequote([,])dnl
+ if test "$ust_cv_i386_is_x86_64" = yes ; then
+ LIBFORMAT="elf64-x86-64"
+ else
+ LIBFORMAT="elf32-i386"
+ fi
+ ;;
+ x86_64) LIBFORMAT="elf64-x86-64" ;;
+ powerpc) LIBFORMAT="elf32-powerpc" ;;
+ ppc64) LIBFORMAT="elf64-powerpc" ;;
+ s390) LIBFORMAT="elf32-s390" ;;
+ s390x) LIBFORMAT="elf64-s390" ;;
+ *) AC_MSG_ERROR([unable to detect library format (unsupported architecture ($host_cpu)?)]) ;;
+esac
+AC_SUBST(LIBFORMAT)
+AC_MSG_RESULT($LIBFORMAT)