diff --git a/acsite.m4 b/acsite.m4
new file mode 100644
index 0000000000..d2cb7c0845
--- /dev/null
+++ b/acsite.m4
@@ -0,0 +1,97 @@
+#These defines are needed because CentOS5 uses a old version of autoconf
+#
+AC_DEFUN([AC_TYPE_INT8_T], [_AC_TYPE_INT(8)])
+AC_DEFUN([AC_TYPE_INT16_T], [_AC_TYPE_INT(16)])
+AC_DEFUN([AC_TYPE_INT32_T], [_AC_TYPE_INT(32)])
+AC_DEFUN([AC_TYPE_INT64_T], [_AC_TYPE_INT(64)])
+AC_DEFUN([AC_TYPE_UINT8_T], [_AC_TYPE_UNSIGNED_INT(8)])
+AC_DEFUN([AC_TYPE_UINT16_T], [_AC_TYPE_UNSIGNED_INT(16)])
+AC_DEFUN([AC_TYPE_UINT32_T], [_AC_TYPE_UNSIGNED_INT(32)])
+AC_DEFUN([AC_TYPE_UINT64_T], [_AC_TYPE_UNSIGNED_INT(64)])
+
+# _AC_TYPE_INT(NBITS)
+# -------------------
+AC_DEFUN([_AC_TYPE_INT],
+[
+  AC_CACHE_CHECK([for int$1_t], [ac_cv_c_int$1_t],
+    [ac_cv_c_int$1_t=no
+     for ac_type in 'int$1_t' 'int' 'long int' \
+	 'long long int' 'short int' 'signed char'; do
+       AC_COMPILE_IFELSE(
+	 [AC_LANG_BOOL_COMPILE_TRY(
+	    [AC_INCLUDES_DEFAULT],
+	    [[0 < ($ac_type) (((($ac_type) 1 << ($1 - 2)) - 1) * 2 + 1)]])],
+	 [AC_COMPILE_IFELSE(
+	    [AC_LANG_BOOL_COMPILE_TRY(
+	       [AC_INCLUDES_DEFAULT],
+	       [[($ac_type) (((($ac_type) 1 << ($1 - 2)) - 1) * 2 + 1)
+	         < ($ac_type) (((($ac_type) 1 << ($1 - 2)) - 1) * 2 + 2)]])],
+	    [],
+	    [AS_CASE([$ac_type], [int$1_t],
+	       [ac_cv_c_int$1_t=yes],
+	       [ac_cv_c_int$1_t=$ac_type])])])
+       test "$ac_cv_c_int$1_t" != no && break
+     done])
+  case $ac_cv_c_int$1_t in #(
+  no|yes) ;; #(
+  *)
+    AC_DEFINE_UNQUOTED([int$1_t], [$ac_cv_c_int$1_t],
+      [Define to the type of a signed integer type of width exactly $1 bits
+       if such a type exists and the standard includes do not define it.]);;
+  esac
+])# _AC_TYPE_INT
+
+# _AC_TYPE_UNSIGNED_INT(NBITS)
+# ----------------------------
+AC_DEFUN([_AC_TYPE_UNSIGNED_INT],
+[
+  AC_CACHE_CHECK([for uint$1_t], [ac_cv_c_uint$1_t],
+    [ac_cv_c_uint$1_t=no
+     for ac_type in 'uint$1_t' 'unsigned int' 'unsigned long int' \
+	 'unsigned long long int' 'unsigned short int' 'unsigned char'; do
+       AC_COMPILE_IFELSE(
+	 [AC_LANG_BOOL_COMPILE_TRY(
+	    [AC_INCLUDES_DEFAULT],
+	    [[($ac_type) -1 >> ($1 - 1) == 1]])],
+	 [AS_CASE([$ac_type], [uint$1_t],
+	    [ac_cv_c_uint$1_t=yes],
+	    [ac_cv_c_uint$1_t=$ac_type])])
+       test "$ac_cv_c_uint$1_t" != no && break
+     done])
+  case $ac_cv_c_uint$1_t in #(
+  no|yes) ;; #(
+  *)
+    m4_bmatch([$1], [^\(8\|32\|64\)$],
+      [AC_DEFINE([_UINT$1_T], 1,
+	 [Define for Solaris 2.5.1 so the uint$1_t typedef from
+	  <sys/synch.h>, <pthread.h>, or <semaphore.h> is not used.
+	  If the typedef was allowed, the #define below would cause a
+	  syntax error.])])
+    AC_DEFINE_UNQUOTED([uint$1_t], [$ac_cv_c_uint$1_t],
+      [Define to the type of an unsigned integer type of width exactly $1 bits
+       if such a type exists and the standard includes do not define it.]);;
+  esac
+])# _AC_TYPE_UNSIGNED_INT
+
+# AS_CASE(WORD, [PATTERN1], [IF-MATCHED1]...[DEFAULT])
+# ----------------------------------------------------
+# Expand into
+# | case WORD in
+# | PATTERN1) IF-MATCHED1 ;;
+# | ...
+# | *) DEFAULT ;;
+# | esac
+m4_define([_AS_CASE],
+[m4_if([$#], 0, [m4_fatal([$0: too few arguments: $#])],
+       [$#], 1, [  *) $1 ;;],
+       [$#], 2, [  $1) m4_default([$2], [:]) ;;],
+       [  $1) m4_default([$2], [:]) ;;
+$0(m4_shiftn(2, $@))])dnl
+])
+m4_defun([AS_CASE],
+[m4_ifval([$2$3],
+[case $1 in
+_AS_CASE(m4_shift($@))
+esac
+])dnl
+])# AS_CASE