+
+@item --enable-decimal-float
+@itemx --enable-decimal-float=yes
+@itemx --enable-decimal-float=no
+@itemx --enable-decimal-float=bid
+@itemx --enable-decimal-float=dpd
+@itemx --disable-decimal-float
+Enable (or disable) support for the C decimal floating point extension
+that is in the IEEE 754R extension to the IEEE754 floating point
+standard. This is enabled by default only on PowerPC, i386, and
+x86_64 GNU/Linux systems. Other systems may also support it, but
+require the user to specifically enable it. You can optionally
+control which decimal floating point format is used (either @samp{bid}
+or @samp{dpd}). The @samp{bid} (binary integer decimal) format is
+default on i386 and x86_64 systems, and the @samp{dpd} (densely packed
+decimal) format is default on PowerPC systems.
+
+@item --enable-fixed-point
+@itemx --disable-fixed-point
+Enable (or disable) support for C fixed-point arithmetic.
+This option is enabled by default for some targets (such as MIPS) which
+have hardware-support for fixed-point operations. On other targets, you
+may enable this option manually.
+
+@item --with-long-double-128
+Specify if @code{long double} type should be 128-bit by default on selected
+GNU/Linux architectures. If using @code{--without-long-double-128},
+@code{long double} will be by default 64-bit, the same as @code{double} type.
+When neither of these configure options are used, the default will be
+128-bit @code{long double} when built against GNU C Library 2.4 and later,
+64-bit @code{long double} otherwise.
+
+@item --with-gmp=@var{pathname}
+@itemx --with-gmp-include=@var{pathname}
+@itemx --with-gmp-lib=@var{pathname}
+@itemx --with-mpfr=@var{pathname}
+@itemx --with-mpfr-include=@var{pathname}
+@itemx --with-mpfr-lib=@var{pathname}
+If you do not have GMP (the GNU Multiple Precision library) and the
+MPFR Libraries installed in a standard location and you want to build
+GCC, you can explicitly specify the directory where they are installed
+(@samp{--with-gmp=@var{gmpinstalldir}},
+@samp{--with-mpfr=@var{mpfrinstalldir}}). The
+@option{--with-gmp=@var{gmpinstalldir}} option is shorthand for
+@option{--with-gmp-lib=@var{gmpinstalldir}/lib} and
+@option{--with-gmp-include=@var{gmpinstalldir}/include}. Likewise the
+@option{--with-mpfr=@var{mpfrinstalldir}} option is shorthand for
+@option{--with-mpfr-lib=@var{mpfrinstalldir}/lib} and
+@option{--with-mpfr-include=@var{mpfrinstalldir}/include}. If these
+shorthand assumptions are not correct, you can use the explicit
+include and lib options directly.
+
+@item --with-debug-prefix-map=@var{map}
+Convert source directory names using @option{-fdebug-prefix-map} when
+building runtime libraries. @samp{@var{map}} is a space-separated
+list of maps of the form @samp{@var{old}=@var{new}}.
+