install.texi: Document MPC requirements, flags etc.

	* doc/install.texi: Document MPC requirements, flags etc.

From-SVN: r147592

gcc/ChangeLog

 2009-05-15  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
+	* doc/install.texi: Document MPC requirements, flags etc.
+
 	* builtins.c (do_mpc_arg1, fold_builtin_ccos): New.
 	(fold_builtin_cexp): Ensure we get a complex REAL_TYPE.
 	Evaluate constant arguments.

gcc/doc/install.texi

@@ -344,8 +344,19 @@ not installed in your default library search path.
 
 Necessary to build libgcj, the GCJ runtime.
 
-@end table
+@item MPC Library version 0.6.0 (or later)
+
+Optional when building GCC@.  Having this library will enable
+additional optimizations on complex numbers.  It can be downloaded
+from @uref{http://www.multiprecision.org/mpc/}.  The
+@option{--with-mpc} configure option should be used if your MPC
+Library is not installed in your default library search path.  See
+also @option{--with-mpc-lib} and @option{--with-mpc-include}.
+Alternatively, if an MPC source distribution is found in a
+subdirectory of your GCC sources named @file{mpc}, it will be built
+together with GCC@.
 
+@end table
 
 @heading Tools/packages necessary for modifying GCC
 @table @asis
@@ -525,11 +536,11 @@ components of the binutils you intend to build alongside the compiler
 (@file{bfd}, @file{binutils}, @file{gas}, @file{gprof}, @file{ld},
 @file{opcodes}, @dots{}) to the directory containing the GCC sources.
 
-Likewise, the GMP and MPFR libraries can be automatically built together
-with GCC.  Unpack the GMP and/or MPFR source distributions in the
-directory containing the GCC sources and rename their directories to
-@file{gmp} and @file{mpfr}, respectively (or use symbolic links with the
-same name).
+Likewise the GMP, MPFR and MPC libraries can be automatically built
+together with GCC.  Unpack the GMP, MPFR and/or MPC source
+distributions in the directory containing the GCC sources and rename
+their directories to @file{gmp}, @file{mpfr} and @file{mpc},
+respectively (or use symbolic links with the same name).
 
 @html
 <hr />
@@ -1488,17 +1499,24 @@ When neither of these configure options are used, the default will be
 @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
+@itemx --with-mpc=@var{pathname}
+@itemx --with-mpc-include=@var{pathname}
+@itemx --with-mpc-lib=@var{pathname}
+If you do not have GMP (the GNU Multiple Precision library), the MPFR
+library and/or the MPC library 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}},
+@samp{--with-mpc=@var{mpcinstalldir}}).  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
+@option{--with-mpfr-include=@var{mpfrinstalldir}/include}, also the
+@option{--with-mpc=@var{mpcinstalldir}} option is shorthand for
+@option{--with-mpc-lib=@var{mpcinstalldir}/lib} and
+@option{--with-mpc-include=@var{mpcinstalldir}/include}.  If these
 shorthand assumptions are not correct, you can use the explicit
 include and lib options directly.