diff --git a/config/ChangeLog b/config/ChangeLog
index c5e044f5a..57c31f485 100644
--- a/config/ChangeLog
+++ b/config/ChangeLog
@@ -1,3 +1,7 @@
+2006-10-14  Geoffrey Keating  <geoffk@apple.com>
+
+	* multi.m4: New file, from automake version 2 branch.
+
 2006-09-18  Tom Tromey  <tromey@redhat.com>
 
 	* tls.m4 (GCC_CHECK_TLS): Pass empty argument as "help arg" to
@@ -6,28 +10,27 @@
 2006-07-25  Paolo Bonzini  <bonzini@gnu.org>
 
 	PR build/26188
-        * stdint.m4: Test for uintptr_t even on systems with uint64_t or uint32_t.
+	* stdint.m4: Test for uintptr_t even on systems with uint64_t or uint32_t.
 
-	Sync from GCC
-	2006-07-21  Steve Ellcey  <sje@cup.hp.com>
+2006-07-21  Steve Ellcey  <sje@cup.hp.com>
 
-        PR target/26792
-        * unwind_ipinfo.m4: New.
+	PR target/26792
+	* unwind_ipinfo.m4: New.
 
-	2006-07-21  David Daney  <ddaney@avtrex.com>
+2006-07-21  David Daney  <ddaney@avtrex.com>
 
-        PR libgcj/28426
-        * gxx-include-dir.m4: Use target_alias in path for cross build.
+	PR libgcj/28426
+	* gxx-include-dir.m4: Use target_alias in path for cross build.
 
 2006-07-18  Paolo Bonzini  <bonzini@gnu.org>
 
-        * acx.m4: Support --with-build-libsubdir and AC_SUBST
-        build_libsubdir.
+	* acx.m4: Support --with-build-libsubdir and AC_SUBST
+	build_libsubdir.
 
 2006-06-13  Richard Earnshaw  <rearnsha@arm.com>
 	    Alexandre Oliva <aoliva@redhat.com>
 
-	* (ZW_GNU_GETTEXT_SISTER_DIR): Add optional
+	* gettext-sister.m4 (ZW_GNU_GETTEXT_SISTER_DIR): Add optional
 	argument for where to search for NLS config file.
 
 2006-05-31  Daniel Jacobowitz  <dan@codesourcery.com>
diff --git a/config/multi.m4 b/config/multi.m4
new file mode 100644
index 000000000..98417679f
--- /dev/null
+++ b/config/multi.m4
@@ -0,0 +1,65 @@
+##                                                          -*- Autoconf -*-
+# Copyright (C) 1998, 1999, 2000, 2001, 2003, 2004, 2005, 2006
+# Free Software Foundation, Inc.
+#
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# serial 6
+
+# AM_ENABLE_MULTILIB([MAKEFILE], [REL-TO-TOP-SRCDIR])
+# ---------------------------------------------------
+# Add --enable-multilib to configure.
+AC_DEFUN([AM_ENABLE_MULTILIB],
+[# Default to --enable-multilib
+AC_ARG_ENABLE(multilib,
+[  --enable-multilib       build many library versions (default)],
+[case "$enableval" in
+  yes) multilib=yes ;;
+  no)  multilib=no ;;
+  *)   AC_MSG_ERROR([bad value $enableval for multilib option]) ;;
+ esac],
+	      [multilib=yes])
+
+# We may get other options which we leave undocumented:
+# --with-target-subdir, --with-multisrctop, --with-multisubdir
+# See config-ml.in if you want the gory details.
+
+if test "$srcdir" = "."; then
+  if test "$with_target_subdir" != "."; then
+    multi_basedir="$srcdir/$with_multisrctop../$2"
+  else
+    multi_basedir="$srcdir/$with_multisrctop$2"
+  fi
+else
+  multi_basedir="$srcdir/$2"
+fi
+AC_SUBST(multi_basedir)
+
+# Even if the default multilib is not a cross compilation,
+# it may be that some of the other multilibs are.
+if test $cross_compiling = no && test $multilib = yes \
+   && test "x${with_multisubdir}" != x ; then
+   cross_compiling=maybe
+fi
+
+AC_OUTPUT_COMMANDS([
+# Only add multilib support code if we just rebuilt the top-level
+# Makefile.
+case " $CONFIG_FILES " in
+ *" ]m4_default([$1],Makefile)[ "*)
+   ac_file=]m4_default([$1],Makefile)[ . ${multi_basedir}/config-ml.in
+   ;;
+esac],
+		   [
+srcdir="$srcdir"
+host="$host"
+target="$target"
+with_multisubdir="$with_multisubdir"
+with_multisrctop="$with_multisrctop"
+with_target_subdir="$with_target_subdir"
+ac_configure_args="${multilib_arg} ${ac_configure_args}"
+multi_basedir="$multi_basedir"
+CONFIG_SHELL=${CONFIG_SHELL-/bin/sh}
+CC="$CC"])])dnl