diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ff9a8412e5a5467b6833af323727c01e8326f186..bbea7ce9a786aee58c282e778fcbbf0eadb0a83d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2006-10-13  David Edelsohn  <edelsohn@gnu.org>
+
+	* doc/install.texi (*-ibm-aix*): Add comment about 32-bit GMP
+	and MPFR for gfortran.
+
 2006-10-13  Carlos O'Donell  <carlos@codesourcery.com>
 
 	* config/elfos.h (MAX_OFILE_ALIGNMENT): Default to largest
diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index a087a35b40d6aaaa27edda3e7da1cec1644afb9a..e76de1f421c1c230af3c9d1e9bad1be83a17e5e1 100644
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -3228,6 +3228,11 @@ and then proceed as described in @uref{build.html,,the build
 instructions}, where we strongly recommend specifying an absolute path
 to invoke @var{srcdir}/configure.
 
+Because GCC on AIX is built as a 32-bit executable by default,
+(although it can generate 64-bit programs) the GMP and MPFR libraries
+required by gfortran must be 32-bit libraries.  Building GMP and MPFR
+as static archive libraries works better than shared libraries.
+
 Errors involving @code{alloca} when building GCC generally are due
 to an incorrect definition of @code{CC} in the Makefile or mixing files
 compiled with the native C compiler and GCC@.  During the stage1 phase of