install.texi: Suggest using LD_LIBRARY_PATH to find libs for GMP, MPFR and MPC.

	* doc/install.texi: Suggest using LD_LIBRARY_PATH to find libs
	for GMP, MPFR and MPC.

Co-Authored-By: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>

From-SVN: r164758

gcc/ChangeLog

+2010-09-30  Jonathan Wakely  <jwakely.gcc@gmail.com>
+            Ralf Wildenhues  <Ralf.Wildenhues@gmx.de>
+
+	* doc/install.texi: Suggest using LD_LIBRARY_PATH to find libs
+	for GMP, MPFR and MPC.
+
 2010-09-30  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	* config/sparc/sparc.opt (mimpure-text): Move ...

gcc/doc/install.texi

@@ -1574,7 +1574,10 @@ they are installed (@samp{--with-gmp=@var{gmpinstalldir}},
 @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.
+include and lib options directly.  You might also need to ensure the
+shared libraries can be found by the dynamic linker when building and
+using GCC, for example by setting the runtime shared library path
+variable (@env{LD_LIBRARY_PATH} on GNU/Linux and Solaris systems).
 
 @item --with-ppl=@var{pathname}
 @itemx --with-ppl-include=@var{pathname}