+Use --without-all if you want to build a small executable with the minimal
+dependencies on external libraries, at the cost of disabling most of the
+features that are normally enabled by default. Using --without-all is
+equivalent to --without-sound --without-dbus --without-libotf
+--without-selinux --without-xft --without-gsettings --without-gnutls
+--without-rsvg --without-xml2 --without-gconf --without-imagemagick
+--without-m17n-flt --without-jpeg --without-tiff --without-gif
+--without-png --without-gpm. Note that --without-all leaves X support
+enabled, and using the GTK2 or GTK3 toolkit creates a lot of library
+dependencies. So if you want to build a small executable with very basic
+X support, use --without-all --with-x-toolkit=no. For the smallest possible
+executable without X, use --without-all --without-x. If you want to build
+with just a few features enabled, you can combine --without-all with
+--with-FEATURE. For example, you can use --without-all --with-dbus
+to build with DBus support and nothing more.
+
+Use --with-wide-int to implement Emacs values with the type 'long long',
+even on hosts where a narrower type would do. With this option, on a
+typical 32-bit host, Emacs integers have 62 bits instead of 30.
+
+Use --enable-gcc-warnings to enable compile-time checks that warn
+about possibly-questionable C code. This is intended for developers
+and is useful with GNU-compatible compilers. On a recent GNU system
+there should be no warnings; on older and on non-GNU systems the
+generated warnings may still be useful.
+
+Use --enable-link-time-optimization to enable link-time optimizer, which
+is available in GNU compiler since version 4.5.0. If your compiler is not
+GNU or older than version 4.5.0, this option does nothing. If `configure'
+can determine number of online CPUS on your system, final link-time
+optimization and code generation is executed in parallel using one job
+per each available online CPU.
+