new file mode 100644
--- /dev/null
+++ b/lib/imaxabs.c
@@ -0,0 +1,29 @@
+/* imaxabs() function: absolute value of 'intmax_t'.
+   Copyright (C) 2006 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+/* Specification.  */
+#include <inttypes.h>
+
+intmax_t
+imaxabs (intmax_t x)
+{
+  return (x >= 0 ? x : - x);
+}

new file mode 100644
--- /dev/null
+++ b/m4/imaxabs.m4
@@ -0,0 +1,17 @@
+# imaxabs.m4 serial 1
+dnl Copyright (C) 2006 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_IMAXABS],
+[
+  AC_REQUIRE([gl_INTTYPES_H])
+  if test "$ac_cv_have_decl_imaxabs" != yes; then
+    AC_LIBOBJ([imaxabs])
+    gl_PREREQ_IMAXABS
+  fi
+])
+
+# Prerequisites of lib/imaxabs.c.
+AC_DEFUN([gl_PREREQ_IMAXABS], [:])

new file mode 100644
--- /dev/null
+++ b/modules/imaxabs
@@ -0,0 +1,23 @@
+Description:
+imaxabs() function: absolute value of 'intmax_t'.
+
+Files:
+lib/imaxabs.c
+m4/imaxabs.m4
+
+Depends-on:
+inttypes
+
+configure.ac:
+gl_FUNC_IMAXABS
+
+Makefile.am:
+
+Include:
+<inttypes.h>
+
+License:
+LGPL
+
+Maintainer:
+Bruno Haible