+forward to maintain the port.
+
+ <br><dt><code>--enable-decimal-float</code><dt><code>--enable-decimal-float=yes</code><dt><code>--enable-decimal-float=no</code><dt><code>--enable-decimal-float=bid</code><dt><code>--enable-decimal-float=dpd</code><dt><code>--disable-decimal-float</code><dd>Enable (or disable) support for the C decimal floating point extension
+that is in the IEEE 754-2008 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><span class="samp">bid</span></samp>’ or ‘<samp><span class="samp">dpd</span></samp>’). The ‘<samp><span class="samp">bid</span></samp>’ (binary integer decimal)
+format is default on i386 and x86_64 systems, and the ‘<samp><span class="samp">dpd</span></samp>’
+(densely packed decimal) format is default on PowerPC systems.
+
+ <br><dt><code>--enable-fixed-point</code><dt><code>--disable-fixed-point</code><dd>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.
+
+ <br><dt><code>--with-long-double-128</code><dd>Specify if <code>long double</code> type should be 128-bit by default on selected
+GNU/Linux architectures. If using <code>--without-long-double-128</code>,
+<code>long double</code> will be by default 64-bit, the same as <code>double</code> type.
+When neither of these configure options are used, the default will be
+128-bit <code>long double</code> when built against GNU C Library 2.4 and later,
+64-bit <code>long double</code> otherwise.
+
+ <br><dt><code>--with-gmp=</code><var>pathname</var><dt><code>--with-gmp-include=</code><var>pathname</var><dt><code>--with-gmp-lib=</code><var>pathname</var><dt><code>--with-mpfr=</code><var>pathname</var><dt><code>--with-mpfr-include=</code><var>pathname</var><dt><code>--with-mpfr-lib=</code><var>pathname</var><dd>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><span class="samp">--with-gmp=</span><var>gmpinstalldir</var></samp>’,
+‘<samp><span class="samp">--with-mpfr=</span><var>mpfrinstalldir</var></samp>’). The
+<samp><span class="option">--with-gmp=</span><var>gmpinstalldir</var></samp> option is shorthand for
+<samp><span class="option">--with-gmp-lib=</span><var>gmpinstalldir</var><span class="option">/lib</span></samp> and
+<samp><span class="option">--with-gmp-include=</span><var>gmpinstalldir</var><span class="option">/include</span></samp>. Likewise the
+<samp><span class="option">--with-mpfr=</span><var>mpfrinstalldir</var></samp> option is shorthand for
+<samp><span class="option">--with-mpfr-lib=</span><var>mpfrinstalldir</var><span class="option">/lib</span></samp> and
+<samp><span class="option">--with-mpfr-include=</span><var>mpfrinstalldir</var><span class="option">/include</span></samp>. If these
+shorthand assumptions are not correct, you can use the explicit
+include and lib options directly.
+
+ <br><dt><code>--with-ppl=</code><var>pathname</var><dt><code>--with-ppl-include=</code><var>pathname</var><dt><code>--with-ppl-lib=</code><var>pathname</var><dt><code>--with-cloog=</code><var>pathname</var><dt><code>--with-cloog-include=</code><var>pathname</var><dt><code>--with-cloog-lib=</code><var>pathname</var><dd>If you do not have PPL (the Parma Polyhedra Library) and the CLooG
+libraries installed in a standard location and you want to build GCC,
+you can explicitly specify the directory where they are installed
+(‘<samp><span class="samp">--with-ppl=</span><var>pplinstalldir</var></samp>’,
+‘<samp><span class="samp">--with-cloog=</span><var>clooginstalldir</var></samp>’). The
+<samp><span class="option">--with-ppl=</span><var>pplinstalldir</var></samp> option is shorthand for
+<samp><span class="option">--with-ppl-lib=</span><var>pplinstalldir</var><span class="option">/lib</span></samp> and
+<samp><span class="option">--with-ppl-include=</span><var>pplinstalldir</var><span class="option">/include</span></samp>. Likewise the
+<samp><span class="option">--with-cloog=</span><var>clooginstalldir</var></samp> option is shorthand for
+<samp><span class="option">--with-cloog-lib=</span><var>clooginstalldir</var><span class="option">/lib</span></samp> and
+<samp><span class="option">--with-cloog-include=</span><var>clooginstalldir</var><span class="option">/include</span></samp>. If these
+shorthand assumptions are not correct, you can use the explicit
+include and lib options directly.
+
+ <br><dt><code>--with-host-libstdcxx=</code><var>linker-args</var><dd>If you are linking with a static copy of PPL, you can use this option
+to specify how the linker should find the standard C++ library used
+internally by PPL. Typical values of <var>linker-args</var> might be
+‘<samp><span class="samp">-lstdc++</span></samp>’ or ‘<samp><span class="samp">-Wl,-Bstatic,-lstdc++,-Bdynamic -lm</span></samp>’. If you are
+linking with a shared copy of PPL, you probably do not need this
+option; shared library dependencies will cause the linker to search
+for the standard C++ library automatically.
+
+ <br><dt><code>--with-debug-prefix-map=</code><var>map</var><dd>Convert source directory names using <samp><span class="option">-fdebug-prefix-map</span></samp> when
+building runtime libraries. ‘<samp><var>map</var></samp>’ is a space-separated
+list of maps of the form ‘<samp><var>old</var><span class="samp">=</span><var>new</var></samp>’.
+
+ </dl>
+
+<h4 class="subheading"><a name="TOC3"></a>Cross-Compiler-Specific Options</h4>
+
+<p>The following options only apply to building cross compilers.
+ <dl>
+<dt><code>--with-sysroot</code><dt><code>--with-sysroot=</code><var>dir</var><dd>Tells GCC to consider <var>dir</var> as the root of a tree that contains a
+(subset of) the root filesystem of the target operating system.
+Target system headers, libraries and run-time object files will be
+searched in there. The specified directory is not copied into the
+install tree, unlike the options <samp><span class="option">--with-headers</span></samp> and
+<samp><span class="option">--with-libs</span></samp> that this option obsoletes. The default value,
+in case <samp><span class="option">--with-sysroot</span></samp> is not given an argument, is
+<samp><span class="option">${gcc_tooldir}/sys-root</span></samp>. If the specified directory is a
+subdirectory of <samp><span class="option">${exec_prefix}</span></samp>, then it will be found relative to
+the GCC binaries if the installation tree is moved.
+
+ <br><dt><code>--with-build-sysroot</code><dt><code>--with-build-sysroot=</code><var>dir</var><dd>Tells GCC to consider <var>dir</var> as the system root (see
+<samp><span class="option">--with-sysroot</span></samp>) while building target libraries, instead of
+the directory specified with <samp><span class="option">--with-sysroot</span></samp>. This option is
+only useful when you are already using <samp><span class="option">--with-sysroot</span></samp>. You
+can use <samp><span class="option">--with-build-sysroot</span></samp> when you are configuring with
+<samp><span class="option">--prefix</span></samp> set to a directory that is different from the one in
+which you are installing GCC and your target libraries.
+
+ <p>This option affects the system root for the compiler used to build
+target libraries (which runs on the build system); it does not affect
+the compiler which is used to build GCC itself.
+
+ <br><dt><code>--with-headers</code><dt><code>--with-headers=</code><var>dir</var><dd>Deprecated in favor of <samp><span class="option">--with-sysroot</span></samp>.
+Specifies that target headers are available when building a cross compiler.
+The <var>dir</var> argument specifies a directory which has the target include
+files. These include files will be copied into the <samp><span class="file">gcc</span></samp> install
+directory. <em>This option with the </em><var>dir</var><em> argument is required</em> when
+building a cross compiler, if <samp><var>prefix</var><span class="file">/</span><var>target</var><span class="file">/sys-include</span></samp>
+doesn't pre-exist. If <samp><var>prefix</var><span class="file">/</span><var>target</var><span class="file">/sys-include</span></samp> does
+pre-exist, the <var>dir</var> argument may be omitted. <samp><span class="command">fixincludes</span></samp>
+will be run on these files to make them compatible with GCC.
+
+ <br><dt><code>--without-headers</code><dd>Tells GCC not use any target headers from a libc when building a cross
+compiler. When crossing to GNU/Linux, you need the headers so GCC
+can build the exception handling for libgcc.
+
+ <br><dt><code>--with-libs</code><dt><code>--with-libs=``</code><var>dir1</var> <var>dir2</var><code> ... </code><var>dirN</var><code>''</code><dd>Deprecated in favor of <samp><span class="option">--with-sysroot</span></samp>.
+Specifies a list of directories which contain the target runtime
+libraries. These libraries will be copied into the <samp><span class="file">gcc</span></samp> install
+directory. If the directory list is omitted, this option has no
+effect.
+
+ <br><dt><code>--with-newlib</code><dd>Specifies that ‘<samp><span class="samp">newlib</span></samp>’ is
+being used as the target C library. This causes <code>__eprintf</code> to be
+omitted from <samp><span class="file">libgcc.a</span></samp> on the assumption that it will be provided by
+‘<samp><span class="samp">newlib</span></samp>’.
+
+ <br><dt><code>--with-build-time-tools=</code><var>dir</var><dd>Specifies where to find the set of target tools (assembler, linker, etc.)
+that will be used while building GCC itself. This option can be useful
+if the directory layouts are different between the system you are building
+GCC on, and the system where you will deploy it.
+
+ <p>For example, on a <samp><span class="option">ia64-hp-hpux</span></samp> system, you may have the GNU
+assembler and linker in <samp><span class="file">/usr/bin</span></samp>, and the native tools in a
+different path, and build a toolchain that expects to find the
+native tools in <samp><span class="file">/usr/bin</span></samp>.
+
+ <p>When you use this option, you should ensure that <var>dir</var> includes
+<samp><span class="command">ar</span></samp>, <samp><span class="command">as</span></samp>, <samp><span class="command">ld</span></samp>, <samp><span class="command">nm</span></samp>,
+<samp><span class="command">ranlib</span></samp> and <samp><span class="command">strip</span></samp> if necessary, and possibly
+<samp><span class="command">objdump</span></samp>. Otherwise, GCC may use an inconsistent set of
+tools.