diff -u /dev/null lib/byteswap_.h
--- /dev/null	2005-04-15 16:25:26.000000000 +0200
+++ lib/byteswap_.h	2005-05-01 13:09:18.000000000 +0200
@@ -0,0 +1,36 @@
+/* byteswap.h - Byte swapping
+   Copyright (C) 2005 Free Software Foundation, Inc.
+   Written by Oskar Liljeblad <address@hidden>, 2005.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this program; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA. */
+
+#ifndef _BYTESWAP_H
+
+#define bswap_16(x) ((((x) & 0x00FF) << 8) | \
+                     (((x) & 0xFF00) >> 8))
+#define bswap_32(x) ((((x) & 0x000000FF) << 24) | \
+                     (((x) & 0x0000FF00) << 8) | \
+                     (((x) & 0x00FF0000) << 8) | \
+                     (((x) & 0xFF000000) >> 24))
+#define bswap_64(x) ((((x) & 0x00000000000000FFULL) << 56) | \
+                     (((x) & 0x000000000000FF00ULL) << 40) | \
+                     (((x) & 0x0000000000FF0000ULL) << 24) | \
+                     (((x) & 0x00000000FF000000ULL) << 8) | \
+		     (((x) & 0x000000FF00000000ULL) >> 8) | \
+                     (((x) & 0x0000FF0000000000ULL) >> 24) | \
+                     (((x) & 0x00FF000000000000ULL) >> 40) | \
+                     (((x) & 0xFF00000000000000ULL) >> 56))
+
+#endif
diff -u /dev/null m4/byteswap.m4
--- /dev/null	2005-04-15 16:25:26.000000000 +0200
+++ m4/byteswap.m4	2005-05-01 12:46:03.000000000 +0200
@@ -0,0 +1,18 @@
+# byteswap.m4 serial 1
+dnl Copyright (C) 2005 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.
+
+dnl Written by Oskar Liljeblad.
+
+AC_DEFUN([gl_BYTESWAP],
+[
+  dnl Prerequisites of lib/byteswap_.h.
+  AC_CHECK_HEADERS([byteswap.h], [
+    BYTESWAP_H=''
+  ], [
+    BYTESWAP_H='byteswap.h'
+  ])
+  AC_SUBST(BYTESWAP_H)
+])
diff -u /dev/null modules/byteswap
--- /dev/null	2005-04-15 16:25:26.000000000 +0200
+++ modules/byteswap	2005-05-01 13:09:26.000000000 +0200
@@ -0,0 +1,32 @@
+Description:
+Swap bytes of 16, 32 and 64 bit values.
+
+Files:
+lib/byteswap_.h
+m4/byteswap.m4
+
+Depends-on:
+
+configure.ac:
+gl_BYTESWAP
+
+Makefile.am:
+BUILT_SOURCES += $(BYTESWAP_H)
+EXTRA_DIST += byteswap_.h
+
+# We need the following in order to create a <byteswap.h> when the system
+# doesn't have one.
+all-local $(lib_OBJECTS): $(BYTESWAP_H)
+byteswap.h: byteswap_.h
+	cp $(srcdir)/$< address@hidden
+	mv address@hidden $@
+MOSTLYCLEANFILES += byteswap.h byteswap.h-t
+
+Include:
+<byteswap.h>
+
+License:
+LGPL
+
+Maintainer:
+Oskar Liljeblad