diff --git a/m4/ax_add_am_macro.m4 b/m4/ax_add_am_macro.m4
index 51ce0d0c2..3962002bf 100644
--- a/m4/ax_add_am_macro.m4
+++ b/m4/ax_add_am_macro.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#      http://www.gnu.org/software/autoconf-archive/ax_add_am_macro.html
+#     https://www.gnu.org/software/autoconf-archive/ax_add_am_macro.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -21,7 +21,7 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 9
+#serial 10
 
 AC_DEFUN([AX_ADD_AM_MACRO],[
   AC_REQUIRE([AX_AM_MACROS])
diff --git a/m4/ax_am_jobserver.m4 b/m4/ax_am_jobserver.m4
index 5a398f8bb..dfbcdbb2f 100644
--- a/m4/ax_am_jobserver.m4
+++ b/m4/ax_am_jobserver.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#      http://www.gnu.org/software/autoconf-archive/ax_am_jobserver.html
+#     https://www.gnu.org/software/autoconf-archive/ax_am_jobserver.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -33,7 +33,7 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 7.1
+#serial 8
 
 AC_DEFUN([AX_AM_JOBSERVER], [
     AC_REQUIRE([AX_COUNT_CPUS])
@@ -44,7 +44,8 @@ AC_DEFUN([AX_AM_JOBSERVER], [
                         yes: enable one more than CPU count
     ],, [enable_jobserver=m4_ifval([$1],[$1],[yes])])
     if test "x$enable_jobserver" = "xyes"; then
-        let enable_jobserver=$CPU_COUNT+1
+        enable_jobserver=$CPU_COUNT
+        ((enable_jobserver++))
     fi
     m4_pattern_allow(AM_MAKEFLAGS)
     if test "x$enable_jobserver" != "xno"; then
diff --git a/m4/ax_am_macros.m4 b/m4/ax_am_macros.m4
index 6b4bd2239..36c3ab6a2 100644
--- a/m4/ax_am_macros.m4
+++ b/m4/ax_am_macros.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#       http://www.gnu.org/software/autoconf-archive/ax_am_macros.html
+#       https://www.gnu.org/software/autoconf-archive/ax_am_macros.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -24,7 +24,7 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 9
+#serial 11
 
 AC_DEFUN([AX_AM_MACROS],
 [
@@ -32,7 +32,7 @@ AC_MSG_NOTICE([adding automake macro support])
 AMINCLUDE="aminclude.am"
 AC_SUBST(AMINCLUDE)
 AC_MSG_NOTICE([creating $AMINCLUDE])
-AMINCLUDE_TIME=`date`
+AMINCLUDE_TIME=`LC_ALL=C date`
 AX_PRINT_TO_FILE([$AMINCLUDE],[[
 # generated automatically by configure from AX_AUTOMAKE_MACROS
 # on $AMINCLUDE_TIME
diff --git a/m4/ax_append_compile_flags.m4 b/m4/ax_append_compile_flags.m4
index 1f8e70845..5b6f1af51 100644
--- a/m4/ax_append_compile_flags.m4
+++ b/m4/ax_append_compile_flags.m4
@@ -1,10 +1,10 @@
-# ===========================================================================
-#  http://www.gnu.org/software/autoconf-archive/ax_append_compile_flags.html
-# ===========================================================================
+# ============================================================================
+#  https://www.gnu.org/software/autoconf-archive/ax_append_compile_flags.html
+# ============================================================================
 #
 # SYNOPSIS
 #
-#   AX_APPEND_COMPILE_FLAGS([FLAG1 FLAG2 ...], [FLAGS-VARIABLE], [EXTRA-FLAGS])
+#   AX_APPEND_COMPILE_FLAGS([FLAG1 FLAG2 ...], [FLAGS-VARIABLE], [EXTRA-FLAGS], [INPUT])
 #
 # DESCRIPTION
 #
@@ -20,6 +20,8 @@
 #   the flags: "CFLAGS EXTRA-FLAGS FLAG".  This can for example be used to
 #   force the compiler to issue an error when a bad flag is given.
 #
+#   INPUT gives an alternative input source to AC_COMPILE_IFELSE.
+#
 #   NOTE: This macro depends on the AX_APPEND_FLAG and
 #   AX_CHECK_COMPILE_FLAG. Please keep this macro in sync with
 #   AX_APPEND_LINK_FLAGS.
@@ -39,7 +41,7 @@
 #   Public License for more details.
 #
 #   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#   with this program. If not, see <https://www.gnu.org/licenses/>.
 #
 #   As a special exception, the respective Autoconf Macro's copyright owner
 #   gives unlimited permission to copy, distribute and modify the configure
@@ -54,12 +56,12 @@
 #   modified version of the Autoconf Macro, you may extend this special
 #   exception to the GPL to apply to your modified version as well.
 
-#serial 3
+#serial 6
 
 AC_DEFUN([AX_APPEND_COMPILE_FLAGS],
-[AC_REQUIRE([AX_CHECK_COMPILE_FLAG])
-AC_REQUIRE([AX_APPEND_FLAG])
+[AX_REQUIRE_DEFINED([AX_CHECK_COMPILE_FLAG])
+AX_REQUIRE_DEFINED([AX_APPEND_FLAG])
 for flag in $1; do
-  AX_CHECK_COMPILE_FLAG([$flag], [AX_APPEND_FLAG([$flag], [$2])], [], [$3])
+  AX_CHECK_COMPILE_FLAG([$flag], [AX_APPEND_FLAG([$flag], [$2])], [], [$3], [$4])
 done
 ])dnl AX_APPEND_COMPILE_FLAGS
diff --git a/m4/ax_append_flag.m4 b/m4/ax_append_flag.m4
index 1d38b76fb..e8c5312af 100644
--- a/m4/ax_append_flag.m4
+++ b/m4/ax_append_flag.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#      http://www.gnu.org/software/autoconf-archive/ax_append_flag.html
+#      https://www.gnu.org/software/autoconf-archive/ax_append_flag.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -34,7 +34,7 @@
 #   Public License for more details.
 #
 #   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#   with this program. If not, see <https://www.gnu.org/licenses/>.
 #
 #   As a special exception, the respective Autoconf Macro's copyright owner
 #   gives unlimited permission to copy, distribute and modify the configure
@@ -49,21 +49,23 @@
 #   modified version of the Autoconf Macro, you may extend this special
 #   exception to the GPL to apply to your modified version as well.
 
-#serial 2
+#serial 7
 
 AC_DEFUN([AX_APPEND_FLAG],
-[AC_PREREQ(2.59)dnl for _AC_LANG_PREFIX
-AS_VAR_PUSHDEF([FLAGS], [m4_default($2,_AC_LANG_PREFIX[FLAGS])])dnl
-AS_VAR_SET_IF(FLAGS,
-  [case " AS_VAR_GET(FLAGS) " in
-    *" $1 "*)
-      AC_RUN_LOG([: FLAGS already contains $1])
-      ;;
-    *)
-      AC_RUN_LOG([: FLAGS="$FLAGS $1"])
-      AS_VAR_SET(FLAGS, ["AS_VAR_GET(FLAGS) $1"])
-      ;;
-   esac],
-  [AS_VAR_SET(FLAGS,["$1"])])
+[dnl
+AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_SET_IF
+AS_VAR_PUSHDEF([FLAGS], [m4_default($2,_AC_LANG_PREFIX[FLAGS])])
+AS_VAR_SET_IF(FLAGS,[
+  AS_CASE([" AS_VAR_GET(FLAGS) "],
+    [*" $1 "*], [AC_RUN_LOG([: FLAGS already contains $1])],
+    [
+     AS_VAR_APPEND(FLAGS,[" $1"])
+     AC_RUN_LOG([: FLAGS="$FLAGS"])
+    ])
+  ],
+  [
+  AS_VAR_SET(FLAGS,[$1])
+  AC_RUN_LOG([: FLAGS="$FLAGS"])
+  ])
 AS_VAR_POPDEF([FLAGS])dnl
 ])dnl AX_APPEND_FLAG
diff --git a/m4/ax_append_link_flags.m4 b/m4/ax_append_link_flags.m4
index 48cbd4bb1..6f7f17456 100644
--- a/m4/ax_append_link_flags.m4
+++ b/m4/ax_append_link_flags.m4
@@ -1,10 +1,10 @@
 # ===========================================================================
-#   http://www.gnu.org/software/autoconf-archive/ax_append_link_flags.html
+#   https://www.gnu.org/software/autoconf-archive/ax_append_link_flags.html
 # ===========================================================================
 #
 # SYNOPSIS
 #
-#   AX_APPEND_LINK_FLAGS([FLAG1 FLAG2 ...], [FLAGS-VARIABLE], [EXTRA-FLAGS])
+#   AX_APPEND_LINK_FLAGS([FLAG1 FLAG2 ...], [FLAGS-VARIABLE], [EXTRA-FLAGS], [INPUT])
 #
 # DESCRIPTION
 #
@@ -19,6 +19,8 @@
 #   EXTRA-FLAGS FLAG".  This can for example be used to force the linker to
 #   issue an error when a bad flag is given.
 #
+#   INPUT gives an alternative input source to AC_COMPILE_IFELSE.
+#
 #   NOTE: This macro depends on the AX_APPEND_FLAG and AX_CHECK_LINK_FLAG.
 #   Please keep this macro in sync with AX_APPEND_COMPILE_FLAGS.
 #
@@ -37,7 +39,7 @@
 #   Public License for more details.
 #
 #   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#   with this program. If not, see <https://www.gnu.org/licenses/>.
 #
 #   As a special exception, the respective Autoconf Macro's copyright owner
 #   gives unlimited permission to copy, distribute and modify the configure
@@ -52,12 +54,12 @@
 #   modified version of the Autoconf Macro, you may extend this special
 #   exception to the GPL to apply to your modified version as well.
 
-#serial 3
+#serial 6
 
 AC_DEFUN([AX_APPEND_LINK_FLAGS],
-[AC_REQUIRE([AX_CHECK_LINK_FLAG])
-AC_REQUIRE([AX_APPEND_FLAG])
+[AX_REQUIRE_DEFINED([AX_CHECK_LINK_FLAG])
+AX_REQUIRE_DEFINED([AX_APPEND_FLAG])
 for flag in $1; do
-  AX_CHECK_LINK_FLAG([$flag], [AX_APPEND_FLAG([$flag], [m4_default([$2], [LDFLAGS])])], [], [$3])
+  AX_CHECK_LINK_FLAG([$flag], [AX_APPEND_FLAG([$flag], [m4_default([$2], [LDFLAGS])])], [], [$3], [$4])
 done
 ])dnl AX_APPEND_LINK_FLAGS
diff --git a/m4/ax_append_to_file.m4 b/m4/ax_append_to_file.m4
index f9f54e088..fca570837 100644
--- a/m4/ax_append_to_file.m4
+++ b/m4/ax_append_to_file.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#     http://www.gnu.org/software/autoconf-archive/ax_append_to_file.html
+#    https://www.gnu.org/software/autoconf-archive/ax_append_to_file.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -19,9 +19,9 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 8
+#serial 9
 
 AC_DEFUN([AX_APPEND_TO_FILE],[
 AC_REQUIRE([AX_FILE_ESCAPES])
-printf "$2\n" >> "$1"
+printf "%s" "$2" >> "$1"
 ])
diff --git a/m4/ax_check_compile_flag.m4 b/m4/ax_check_compile_flag.m4
index c3a8d695a..dcabb92a1 100644
--- a/m4/ax_check_compile_flag.m4
+++ b/m4/ax_check_compile_flag.m4
@@ -1,10 +1,10 @@
 # ===========================================================================
-#   http://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html
+#  https://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html
 # ===========================================================================
 #
 # SYNOPSIS
 #
-#   AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS])
+#   AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
 #
 # DESCRIPTION
 #
@@ -19,6 +19,8 @@
 #   the flags: "CFLAGS EXTRA-FLAGS FLAG".  This can for example be used to
 #   force the compiler to issue an error when a bad flag is given.
 #
+#   INPUT gives an alternative input source to AC_COMPILE_IFELSE.
+#
 #   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
 #   macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG.
 #
@@ -38,7 +40,7 @@
 #   Public License for more details.
 #
 #   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#   with this program. If not, see <https://www.gnu.org/licenses/>.
 #
 #   As a special exception, the respective Autoconf Macro's copyright owner
 #   gives unlimited permission to copy, distribute and modify the configure
@@ -53,19 +55,19 @@
 #   modified version of the Autoconf Macro, you may extend this special
 #   exception to the GPL to apply to your modified version as well.
 
-#serial 2
+#serial 5
 
 AC_DEFUN([AX_CHECK_COMPILE_FLAG],
-[AC_PREREQ(2.59)dnl for _AC_LANG_PREFIX
+[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
 AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl
 AC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [
   ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS
   _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1"
-  AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
+  AC_COMPILE_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
     [AS_VAR_SET(CACHEVAR,[yes])],
     [AS_VAR_SET(CACHEVAR,[no])])
   _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags])
-AS_IF([test x"AS_VAR_GET(CACHEVAR)" = xyes],
+AS_VAR_IF(CACHEVAR,yes,
   [m4_default([$2], :)],
   [m4_default([$3], :)])
 AS_VAR_POPDEF([CACHEVAR])dnl
diff --git a/m4/ax_check_library.m4 b/m4/ax_check_library.m4
index dd27ff41f..4def2f4d2 100644
--- a/m4/ax_check_library.m4
+++ b/m4/ax_check_library.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#     http://www.gnu.org/software/autoconf-archive/ax_check_library.html
+#     https://www.gnu.org/software/autoconf-archive/ax_check_library.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -32,7 +32,6 @@
 #
 # LICENSE
 #
-#   Copyright (c) 2012 Brian Aker <brian@tangent.org>
 #   Copyright (c) 2010 Diego Elio Petteno` <flameeyes@gmail.com>
 #
 #   This program is free software: you can redistribute it and/or modify it
@@ -46,7 +45,7 @@
 #   Public License for more details.
 #
 #   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#   with this program. If not, see <https://www.gnu.org/licenses/>.
 #
 #   As a special exception, the respective Autoconf Macro's copyright owner
 #   gives unlimited permission to copy, distribute and modify the configure
@@ -61,35 +60,36 @@
 #   modified version of the Autoconf Macro, you may extend this special
 #   exception to the GPL to apply to your modified version as well.
 
-#serial 7
+#serial 5
 
-AC_DEFUN([AX_CHECK_LIBRARY],
-    [AC_ARG_VAR($1[_CPPFLAGS],[C preprocessor flags for ]$1[ headers])
-    AC_ARG_VAR($1[_LDFLAGS],[linker flags for ]$1[ libraries])
+AC_DEFUN([AX_CHECK_LIBRARY], [
+  AC_ARG_VAR($1[_CPPFLAGS], [C preprocessor flags for ]$1[ headers])
+  AC_ARG_VAR($1[_LDFLAGS], [linker flags for ]$1[ libraries])
 
-    AC_CACHE_VAL(AS_TR_SH([ax_cv_have_]$1),
-      [AX_SAVE_FLAGS
+  AC_CACHE_VAL(AS_TR_SH([ax_cv_have_]$1),
+    [save_CPPFLAGS="$CPPFLAGS"
+     save_LDFLAGS="$LDFLAGS"
+     save_LIBS="$LIBS"
 
-      AS_IF([test "x$]$1[_CPPFLAGS" != "x"],
-        [CPPFLAGS="$CPPFLAGS $]$1[_CPPFLAGS"])
+     AS_IF([test "x$]$1[_CPPFLAGS" != "x"],
+       [CPPFLAGS="$CPPFLAGS $]$1[_CPPFLAGS"])
 
-      AS_IF([test "x$]$1[_LDFLAGS" != "x"],
-        [LDFLAGS="$LDFLAGS $]$1[_LDFLAGS"])
+     AS_IF([test "x$]$1[_LDFLAGS" != "x"],
+       [LDFLAGS="$LDFLAGS $]$1[_LDFLAGS"])
 
-      AC_CHECK_HEADER($2, [
-        AC_CHECK_LIB($3, [main],
-          [AS_TR_SH([ax_cv_have_]$1)=yes],
-          [AS_TR_SH([ax_cv_have_]$1)=no])
-        ], [AS_TR_SH([ax_cv_have_]$1)=no])
+     AC_CHECK_HEADER($2, [
+       AC_CHECK_LIB($3, [main],
+         [AS_TR_SH([ax_cv_have_]$1)=yes],
+         [AS_TR_SH([ax_cv_have_]$1)=no])
+     ], [AS_TR_SH([ax_cv_have_]$1)=no])
 
-      AX_RESTORE_FLAGS
-      ])
-
-    AS_IF([test "$]AS_TR_SH([ax_cv_have_]$1)[" = "yes"],
-        [AC_DEFINE([HAVE_]$1, [1], [Define to 1 if ]$1[ is found])
-        AC_SUBST($1[_CPPFLAGS])
-        AC_SUBST($1[_LDFLAGS])
-        AC_SUBST($1[_LIB],[-l]$3)
-        ifelse([$4], , :, [$4])],
-        [ifelse([$5], , :, [$5])])
+     CPPFLAGS="$save_CPPFLAGS"
+     LDFLAGS="$save_LDFLAGS"
+     LIBS="$save_LIBS"
     ])
+
+  AS_IF([test "$]AS_TR_SH([ax_cv_have_]$1)[" = "yes"],
+    AC_DEFINE([HAVE_]$1, [1], [Define to 1 if ]$1[ is found])
+    [$4],
+    [$5])
+])
diff --git a/m4/ax_check_link_flag.m4 b/m4/ax_check_link_flag.m4
index e2d0d363e..819409a20 100644
--- a/m4/ax_check_link_flag.m4
+++ b/m4/ax_check_link_flag.m4
@@ -1,10 +1,10 @@
 # ===========================================================================
-#    http://www.gnu.org/software/autoconf-archive/ax_check_link_flag.html
+#    https://www.gnu.org/software/autoconf-archive/ax_check_link_flag.html
 # ===========================================================================
 #
 # SYNOPSIS
 #
-#   AX_CHECK_LINK_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS])
+#   AX_CHECK_LINK_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
 #
 # DESCRIPTION
 #
@@ -19,6 +19,8 @@
 #   EXTRA-FLAGS FLAG".  This can for example be used to force the linker to
 #   issue an error when a bad flag is given.
 #
+#   INPUT gives an alternative input source to AC_LINK_IFELSE.
+#
 #   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
 #   macro in sync with AX_CHECK_{PREPROC,COMPILE}_FLAG.
 #
@@ -38,7 +40,7 @@
 #   Public License for more details.
 #
 #   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#   with this program. If not, see <https://www.gnu.org/licenses/>.
 #
 #   As a special exception, the respective Autoconf Macro's copyright owner
 #   gives unlimited permission to copy, distribute and modify the configure
@@ -53,18 +55,19 @@
 #   modified version of the Autoconf Macro, you may extend this special
 #   exception to the GPL to apply to your modified version as well.
 
-#serial 2
+#serial 5
 
 AC_DEFUN([AX_CHECK_LINK_FLAG],
-[AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_ldflags_$4_$1])dnl
+[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
+AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_ldflags_$4_$1])dnl
 AC_CACHE_CHECK([whether the linker accepts $1], CACHEVAR, [
   ax_check_save_flags=$LDFLAGS
   LDFLAGS="$LDFLAGS $4 $1"
-  AC_LINK_IFELSE([AC_LANG_PROGRAM()],
+  AC_LINK_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
     [AS_VAR_SET(CACHEVAR,[yes])],
     [AS_VAR_SET(CACHEVAR,[no])])
   LDFLAGS=$ax_check_save_flags])
-AS_IF([test x"AS_VAR_GET(CACHEVAR)" = xyes],
+AS_VAR_IF(CACHEVAR,yes,
   [m4_default([$2], :)],
   [m4_default([$3], :)])
 AS_VAR_POPDEF([CACHEVAR])dnl
diff --git a/m4/ax_compiler_version.m4 b/m4/ax_compiler_version.m4
index e074cf743..0581d1bc0 100644
--- a/m4/ax_compiler_version.m4
+++ b/m4/ax_compiler_version.m4
@@ -1,100 +1,529 @@
 # ===========================================================================
-#      https://github.com/BrianAker/ddm4/
+#   https://www.gnu.org/software/autoconf-archive/ax_compiler_version.html
 # ===========================================================================
 #
 # SYNOPSIS
 #
-#   AX_COMPILER_VERSION()
+#   AX_COMPILER_VERSION
 #
 # DESCRIPTION
 #
-#   Capture version of C/C++ compiler
+#   This macro retrieves the compiler version and returns it in the cache
+#   variable $ax_cv_c_compiler_version for C and $ax_cv_cxx_compiler_version
+#   for C++.
+#
+#   Version is returned as epoch:major.minor.patchversion
+#
+#   Epoch is used in order to have an increasing version number in case of
+#   marketing change.
+#
+#   Epoch use: * borland compiler use chronologically 0turboc for turboc
+#   era,
+#
+#     1borlanc BORLANDC++ before 5, 2cppbuilder for cppbuilder era,
+#     3borlancpp for return of BORLANDC++ (after version 5.5),
+#     4cppbuilder for cppbuilder with year version,
+#     and 5xe for XE era.
+#
+#   An empty string is returned otherwise.
 #
 # LICENSE
 #
-#  Copyright (C) 2012 Brian Aker
-#  All rights reserved.
-#  
-#  Redistribution and use in source and binary forms, with or without
-#  modification, are permitted provided that the following conditions are
-#  met:
-#  
-#      * Redistributions of source code must retain the above copyright
-#  notice, this list of conditions and the following disclaimer.
-#  
-#      * Redistributions in binary form must reproduce the above
-#  copyright notice, this list of conditions and the following disclaimer
-#  in the documentation and/or other materials provided with the
-#  distribution.
-#  
-#      * The names of its contributors may not be used to endorse or
-#  promote products derived from this software without specific prior
-#  written permission.
-#  
-#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-#  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-#  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-#  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-#  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-#  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-#  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-#  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-#  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-#  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-#  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#   Copyright (c) 2014 Bastien ROUCARIES <roucaries.bastien+autoconf@gmail.com>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved. This file is offered as-is, without any
+#   warranty.
 
-#serial 5
-AC_DEFUN([_C_COMPILER_VERSION],
-    [AC_MSG_CHECKING([C Compiler version])
+#serial 12
 
-    AS_CASE(["$ax_cv_c_compiler_vendor"],
-      [sun],[ax_c_compiler_version=`$CC -V 2>&1 | sed 1q`],
-      [intel],[ax_c_compiler_version=`$CC --version 2>&1 | sed 1q`],
-      [clang],[ax_c_compiler_version=`$CC --version 2>&1 | sed 1q`],
-      [gnu],[ax_c_compiler_version=`$CC --version | sed 1q`],
-      [mingw],[ax_c_compiler_version=`$CC --version | sed 1q`],
-      [ax_c_compiler_version="unknown: $ax_cv_c_compiler_vendor"])
-
-    AC_MSG_RESULT(["$ax_c_compiler_version"])
-    AC_SUBST([CC_VERSION_VENDOR],["$ax_cv_c_compiler_vendor"])
-    AC_SUBST([CC_VERSION],["$ax_c_compiler_version"])
+# for intel
+AC_DEFUN([_AX_COMPILER_VERSION_INTEL],
+  [ dnl
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+    [__INTEL_COMPILER/100],,
+    AC_MSG_FAILURE([[[$0]] unknown intel compiler version]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+    [(__INTEL_COMPILER%100)/10],,
+    AC_MSG_FAILURE([[[$0]] unknown intel compiler version]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+    [(__INTEL_COMPILER%10)],,
+    AC_MSG_FAILURE([[[$0]] unknown intel compiler version]))
+  ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch"
   ])
 
-AC_DEFUN([_CXX_COMPILER_VERSION],
-    [AC_MSG_CHECKING([C++ Compiler version])
-
-    AS_CASE(["$ax_cv_c_compiler_vendor"],
-      [sun],[ax_cxx_compiler_version=`$CXX -V 2>&1 | sed 1q`],
-      [intel],[ax_cxx_compiler_version=`$CXX --version 2>&1 | sed 1q`],
-      [clang],[ax_cxx_compiler_version=`$CXX --version 2>&1 | sed 1q`],
-      [gnu],[ax_cxx_compiler_version=`$CXX --version | sed 1q`],
-      [mingw],[ax_cxx_compiler_version=`$CXX --version | sed 1q`],
-      [ax_cxx_compiler_version="unknown: $ax_cv_c_compiler_vendor"])
-
-    AC_MSG_RESULT(["$ax_cxx_compiler_version"])
-    AC_SUBST([CXX_VERSION_VENDOR],["$ax_cv_c_compiler_vendor"])
-    AC_SUBST([CXX_VERSION],["$ax_cxx_compiler_version"])
+# for IBM
+AC_DEFUN([_AX_COMPILER_VERSION_IBM],
+  [ dnl
+  dnl check between z/OS C/C++  and XL C/C++
+  AC_COMPILE_IFELSE([
+    AC_LANG_PROGRAM([],
+      [
+        #if defined(__COMPILER_VER__)
+        choke me;
+        #endif
+      ])],
+    [
+      AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+        [__xlC__/100],,
+      	AC_MSG_FAILURE([[[$0]] unknown IBM compiler major version]))
+      AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+        [__xlC__%100],,
+      	AC_MSG_FAILURE([[[$0]] unknown IBM compiler minor version]))
+      AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+        [__xlC_ver__/0x100],,
+      	AC_MSG_FAILURE([[[$0]] unknown IBM compiler patch version]))
+      AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_build,
+        [__xlC_ver__%0x100],,
+      	AC_MSG_FAILURE([[[$0]] unknown IBM compiler build version]))
+      ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_build"
+    ],
+    [
+      AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+        [__xlC__%1000],,
+      	AC_MSG_FAILURE([[[$0]] unknown IBM compiler patch version]))
+      AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+        [(__xlC__/10000)%10],,
+      	AC_MSG_FAILURE([[[$0]] unknown IBM compiler minor version]))
+      AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+        [(__xlC__/100000)%10],,
+      	AC_MSG_FAILURE([[[$0]] unknown IBM compiler major version]))
+      ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch"
     ])
+])
 
-AC_DEFUN([AX_COMPILER_VERSION],
-    [AC_REQUIRE([AX_COMPILER_VENDOR])
+# for pathscale
+AC_DEFUN([_AX_COMPILER_VERSION_PATHSCALE],[
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+    __PATHCC__,,
+    AC_MSG_FAILURE([[[$0]] unknown pathscale major]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+    __PATHCC_MINOR__,,
+    AC_MSG_FAILURE([[[$0]] unknown pathscale minor]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+    [__PATHCC_PATCHLEVEL__],,
+    AC_MSG_FAILURE([[[$0]] unknown pathscale patch level]))
+  ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch"
+  ])
 
-    AC_MSG_CHECKING([MINGW])
-    AC_CHECK_DECL([__MINGW32__],
-      [MINGW=yes
-      ax_c_compiler_version_vendor=mingw],
-      [MINGW=no])
-    AC_MSG_RESULT([$MINGW])
+# for clang
+AC_DEFUN([_AX_COMPILER_VERSION_CLANG],[
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+    __clang_major__,,
+    AC_MSG_FAILURE([[[$0]] unknown clang major]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+    __clang_minor__,,
+    AC_MSG_FAILURE([[[$0]] unknown clang minor]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+    [__clang_patchlevel__],,0)
+  ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch"
+  ])
 
-    AC_REQUIRE([_C_COMPILER_VERSION])
-    AC_REQUIRE([_CXX_COMPILER_VERSION])
-    AS_IF([test "x$GCC" = xyes],
-      [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-#if !defined(__GNUC__) || (__GNUC__ < 4) || ((__GNUC__ >= 4) && (__GNUC_MINOR__ < 7))
-# error GCC is Too Old!
-#endif
-          ]])],
-        [ac_c_gcc_recent=yes],
-        [ac_c_gcc_recent=no])
+# for crayc
+AC_DEFUN([_AX_COMPILER_VERSION_CRAY],[
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+    _RELEASE,,
+    AC_MSG_FAILURE([[[$0]] unknown crayc release]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+    _RELEASE_MINOR,,
+    AC_MSG_FAILURE([[[$0]] unknown crayc minor]))
+  ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor"
+  ])
+
+# for fujitsu
+AC_DEFUN([_AX_COMPILER_VERSION_FUJITSU],[
+  AC_COMPUTE_INT(ax_cv_[]_AC_LANG_ABBREV[]_compiler_version,
+                 __FCC_VERSION,,
+		 AC_MSG_FAILURE([[[$0]]unknown fujitsu release]))
+  ])
+
+# for GNU
+AC_DEFUN([_AX_COMPILER_VERSION_GNU],[
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+    __GNUC__,,
+    AC_MSG_FAILURE([[[$0]] unknown gcc major]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+    __GNUC_MINOR__,,
+    AC_MSG_FAILURE([[[$0]] unknown gcc minor]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+    [__GNUC_PATCHLEVEL__],,
+    AC_MSG_FAILURE([[[$0]] unknown gcc patch level]))
+  ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch"
+  ])
+
+# For sun
+AC_DEFUN([_AX_COMPILER_VERSION_SUN],[
+  m4_define([_AX_COMPILER_VERSION_SUN_NUMBER],
+            [
+	     #if defined(__SUNPRO_CC)
+	     __SUNPRO_CC
+	     #else
+	     __SUNPRO_C
+	     #endif
+	    ])
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_until59,
+    !!(_AX_COMPILER_VERSION_SUN_NUMBER < 0x1000),,
+    AC_MSG_FAILURE([[[$0]] unknown sun release version]))
+  AS_IF([test "X$_ax_[]_AC_LANG_ABBREV[]_compiler_version_until59" = X1],
+    [dnl
+      AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+        _AX_COMPILER_VERSION_SUN_NUMBER % 0x10,,
+	AC_MSG_FAILURE([[[$0]] unknown sun patch version]))
+      AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+        (_AX_COMPILER_VERSION_SUN_NUMBER / 0x10) % 0x10,,
+        AC_MSG_FAILURE([[[$0]] unknown sun minor version]))
+      AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+        (_AX_COMPILER_VERSION_SUN_NUMBER / 0x100),,
+        AC_MSG_FAILURE([[[$0]] unknown sun major version]))
+    ],
+    [dnl
+      AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+        _AX_COMPILER_VERSION_SUN_NUMBER % 0x10,,
+        AC_MSG_FAILURE([[[$0]] unknown sun patch version]))
+      AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+        (_AX_COMPILER_VERSION_SUN_NUMBER / 0x100) % 0x100,,
+        AC_MSG_FAILURE([[[$0]] unknown sun minor version]))
+      AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+        (_AX_COMPILER_VERSION_SUN_NUMBER / 0x1000),,
+        AC_MSG_FAILURE([[[$0]] unknown sun major version]))
+    ])
+  ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch"
+])
+
+AC_DEFUN([_AX_COMPILER_VERSION_HP],[
+  m4_define([_AX_COMPILER_VERSION_HP_NUMBER],
+            [
+	     #if defined(__HP_cc)
+	     __HP_cc
+	     #else
+	     __HP_aCC
+	     #endif
+	    ])
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_untilA0121,
+    !!(_AX_COMPILER_VERSION_HP_NUMBER <= 1),,
+    AC_MSG_FAILURE([[[$0]] unknown hp release version]))
+  AS_IF([test "X$_ax_[]_AC_LANG_ABBREV[]_compiler_version_untilA0121" = X1],
+    [dnl By default output last version with this behavior.
+     dnl it is so old
+      ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="01.21.00"
+    ],
+    [dnl
+      AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+        (_AX_COMPILER_VERSION_HP_NUMBER % 100),,
+        AC_MSG_FAILURE([[[$0]] unknown hp release version]))
+      AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+        ((_AX_COMPILER_VERSION_HP_NUMBER / 100)%100),,
+        AC_MSG_FAILURE([[[$0]] unknown hp minor version]))
+      AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+        ((_AX_COMPILER_VERSION_HP_NUMBER / 10000)%100),,
+        AC_MSG_FAILURE([[[$0]] unknown hp major version]))
+      ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch"
+    ])
+])
+
+AC_DEFUN([_AX_COMPILER_VERSION_DEC],[dnl
+  m4_define([_AX_COMPILER_VERSION_DEC_NUMBER],
+            [
+	     #if defined(__DECC_VER)
+	     __DECC_VER
+	     #else
+	     __DECCXX_VER
+	     #endif
+	    ])
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+    (_AX_COMPILER_VERSION_DEC_NUMBER % 10000),,
+    AC_MSG_FAILURE([[[$0]] unknown dec release version]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+    ((_AX_COMPILER_VERSION_DEC_NUMBER / 100000UL)%100),,
+    AC_MSG_FAILURE([[[$0]] unknown dec minor version]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+    ((_AX_COMPILER_VERSION_DEC_NUMBER / 10000000UL)%100),,
+    AC_MSG_FAILURE([[[$0]] unknown dec major version]))
+  ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch"
+  ])
+
+# borland
+AC_DEFUN([_AX_COMPILER_VERSION_BORLAND],[dnl
+  m4_define([_AX_COMPILER_VERSION_TURBOC_NUMBER],
+            [
+	     #if defined(__TURBOC__)
+	     __TURBOC__
+	     #else
+	     choke me
+	     #endif
+	    ])
+  m4_define([_AX_COMPILER_VERSION_BORLANDC_NUMBER],
+            [
+	     #if defined(__BORLANDC__)
+	     __BORLANDC__
+	     #else
+	     __CODEGEARC__
+	     #endif
+	    ])
+ AC_COMPILE_IFELSE(
+   [AC_LANG_PROGRAM(,
+     _AX_COMPILER_VERSION_TURBOC_NUMBER)],
+   [dnl TURBOC
+     AC_COMPUTE_INT(
+       _ax_[]_AC_LANG_ABBREV[]_compiler_version_turboc_raw,
+       _AX_COMPILER_VERSION_TURBOC_NUMBER,,
+       AC_MSG_FAILURE([[[$0]] unknown turboc version]))
+     AS_IF(
+       [test $_ax_[]_AC_LANG_ABBREV[]_compiler_version_turboc_raw -lt 661 || test $_ax_[]_AC_LANG_ABBREV[]_compiler_version_turboc_raw -gt 1023],
+       [dnl compute normal version
+        AC_COMPUTE_INT(
+	  _ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+	  _AX_COMPILER_VERSION_TURBOC_NUMBER % 0x100,,
+	  AC_MSG_FAILURE([[[$0]] unknown turboc minor version]))
+	AC_COMPUTE_INT(
+	  _ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+	  (_AX_COMPILER_VERSION_TURBOC_NUMBER/0x100)%0x100,,
+	  AC_MSG_FAILURE([[[$0]] unknown turboc major version]))
+	ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="0turboc:$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor"],
+      [dnl special version
+       AS_CASE([$_ax_[]_AC_LANG_ABBREV[]_compiler_version_turboc_raw],
+         [661],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="0turboc:1.00"],
+	 [662],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="0turboc:1.01"],
+         [663],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="0turboc:2.00"],
+	 [
+	 AC_MSG_WARN([[[$0]] unknown turboc version between 0x295 and 0x400 please report bug])
+	 ax_cv_[]_AC_LANG_ABBREV[]_compiler_version=""
+	 ])
+      ])
+    ],
+    # borlandc
+    [
+    AC_COMPUTE_INT(
+      _ax_[]_AC_LANG_ABBREV[]_compiler_version_borlandc_raw,
+      _AX_COMPILER_VERSION_BORLANDC_NUMBER,,
+      AC_MSG_FAILURE([[[$0]] unknown borlandc version]))
+    AS_CASE([$_ax_[]_AC_LANG_ABBREV[]_compiler_version_borlandc_raw],
+      dnl BORLANDC++ before 5.5
+      [512] ,[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="1borlanc:2.00"],
+      [1024],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="1borlanc:3.00"],
+      [1024],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="1borlanc:3.00"],
+      [1040],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="1borlanc:3.1"],
+      [1106],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="1borlanc:4.0"],
+      [1280],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="1borlanc:5.0"],
+      [1312],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="1borlanc:5.02"],
+      dnl C++ Builder era
+      [1328],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="2cppbuilder:3.0"],
+      [1344],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="2cppbuilder:4.0"],
+      dnl BORLANDC++ after 5.5
+      [1360],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="3borlancpp:5.5"],
+      [1361],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="3borlancpp:5.51"],
+      [1378],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="3borlancpp:5.6.4"],
+      dnl C++ Builder with year number
+      [1392],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="4cppbuilder:2006"],
+      [1424],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="4cppbuilder:2007"],
+      [1555],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="4cppbuilder:2009"],
+      [1569],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="4cppbuilder:2010"],
+      dnl XE version
+      [1584],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="5xe"],
+      [1600],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="5xe:2"],
+      [1616],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="5xe:3"],
+      [1632],[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="5xe:4"],
+      [
+      AC_MSG_WARN([[[$0]] Unknown borlandc compiler version $_ax_[]_AC_LANG_ABBREV[]_compiler_version_borlandc_raw please report bug])
       ])
     ])
+  ])
+
+# COMO
+AC_DEFUN([_AX_COMPILER_VERSION_COMEAU],
+  [ dnl
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+    [__COMO_VERSION__%100],,
+    AC_MSG_FAILURE([[[$0]] unknown comeau compiler minor version]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+    [(__COMO_VERSION__/100)%10],,
+    AC_MSG_FAILURE([[[$0]] unknown comeau compiler major version]))
+  ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor"
+  ])
+
+# KAI
+AC_DEFUN([_AX_COMPILER_VERSION_KAI],[
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+    [__KCC_VERSION%100],,
+    AC_MSG_FAILURE([[[$0]] unknown kay compiler patch version]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+    [(__KCC_VERSION/100)%10],,
+    AC_MSG_FAILURE([[[$0]] unknown kay compiler minor version]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+    [(__KCC_VERSION/1000)%10],,
+    AC_MSG_FAILURE([[[$0]] unknown kay compiler major version]))
+  ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch"
+  ])
+
+dnl LCC
+dnl LCC does not output version...
+
+# SGI
+AC_DEFUN([_AX_COMPILER_VERSION_SGI],[
+   m4_define([_AX_COMPILER_VERSION_SGI_NUMBER],
+            [
+	     #if defined(_COMPILER_VERSION)
+	     _COMPILER_VERSION
+	     #else
+	     _SGI_COMPILER_VERSION
+	     #endif
+	    ])
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+    [_AX_COMPILER_VERSION_SGI_NUMBER%10],,
+    AC_MSG_FAILURE([[[$0]] unknown SGI compiler patch version]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+    [(_AX_COMPILER_VERSION_SGI_NUMBER/10)%10],,
+    AC_MSG_FAILURE([[[$0]] unknown SGI compiler minor version]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+    [(_AX_COMPILER_VERSION_SGI_NUMBER/100)%10],,
+    AC_MSG_FAILURE([[[$0]] unknown SGI compiler major version]))
+  ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch"
+  ])
+
+# microsoft
+AC_DEFUN([_AX_COMPILER_VERSION_MICROSOFT],[
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+    _MSC_VER%100,,
+    AC_MSG_FAILURE([[[$0]] unknown microsoft compiler minor version]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+    (_MSC_VER/100)%100,,
+    AC_MSG_FAILURE([[[$0]] unknown microsoft compiler major version]))
+  dnl could be overridden
+  _ax_[]_AC_LANG_ABBREV[]_compiler_version_patch=0
+  _ax_[]_AC_LANG_ABBREV[]_compiler_version_build=0
+  # special case for version 6
+  AS_IF([test "X$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major" = "X12"],
+    [AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+       _MSC_FULL_VER%1000,,
+       _ax_[]_AC_LANG_ABBREV[]_compiler_version_patch=0)])
+  # for version 7
+  AS_IF([test "X$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major" = "X13"],
+    [AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+       _MSC_FULL_VER%1000,,
+       AC_MSG_FAILURE([[[$0]] unknown microsoft compiler patch version]))
+    ])
+  # for version > 8
+ AS_IF([test $_ax_[]_AC_LANG_ABBREV[]_compiler_version_major -ge 14],
+    [AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+       _MSC_FULL_VER%10000,,
+       AC_MSG_FAILURE([[[$0]] unknown microsoft compiler patch version]))
+    ])
+ AS_IF([test $_ax_[]_AC_LANG_ABBREV[]_compiler_version_major -ge 15],
+    [AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_build,
+       _MSC_BUILD,,
+       AC_MSG_FAILURE([[[$0]] unknown microsoft compiler build version]))
+    ])
+ ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_build"
+ ])
+
+# for metrowerks
+AC_DEFUN([_AX_COMPILER_VERSION_METROWERKS],[dnl
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+    __MWERKS__%0x100,,
+    AC_MSG_FAILURE([[[$0]] unknown metrowerks compiler patch version]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+    (__MWERKS__/0x100)%0x10,,
+    AC_MSG_FAILURE([[[$0]] unknown metrowerks compiler minor version]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+    (__MWERKS__/0x1000)%0x10,,
+    AC_MSG_FAILURE([[[$0]] unknown metrowerks compiler major version]))
+  ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch"
+  ])
+
+# for watcom
+AC_DEFUN([_AX_COMPILER_VERSION_WATCOM],[dnl
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+    __WATCOMC__%100,,
+    AC_MSG_FAILURE([[[$0]] unknown watcom compiler minor version]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+    (__WATCOMC__/100)%100,,
+    AC_MSG_FAILURE([[[$0]] unknown watcom compiler major version]))
+  ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor"
+  ])
+
+# for PGI
+AC_DEFUN([_AX_COMPILER_VERSION_PORTLAND],[
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+    __PGIC__,,
+    AC_MSG_FAILURE([[[$0]] unknown pgi major]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+    __PGIC_MINOR__,,
+    AC_MSG_FAILURE([[[$0]] unknown pgi minor]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+    [__PGIC_PATCHLEVEL__],,
+    AC_MSG_FAILURE([[[$0]] unknown pgi patch level]))
+  ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch"
+  ])
+
+# tcc
+AC_DEFUN([_AX_COMPILER_VERSION_TCC],[
+  ax_cv_[]_AC_LANG_ABBREV[]_compiler_version=[`tcc -v | $SED 's/^[ ]*tcc[ ]\+version[ ]\+\([0-9.]\+\).*/\1/g'`]
+  ])
+
+# for GNU
+AC_DEFUN([_AX_COMPILER_VERSION_SDCC],[
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_major,
+    /* avoid parse error with comments */
+    #if(defined(__SDCC_VERSION_MAJOR))
+	__SDCC_VERSION_MAJOR
+    #else
+	SDCC/100
+    #endif
+    ,,
+    AC_MSG_FAILURE([[[$0]] unknown sdcc major]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor,
+    /* avoid parse error with comments */
+    #if(defined(__SDCC_VERSION_MINOR))
+	__SDCC_VERSION_MINOR
+    #else
+	(SDCC%100)/10
+    #endif
+    ,,
+    AC_MSG_FAILURE([[[$0]] unknown sdcc minor]))
+  AC_COMPUTE_INT(_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch,
+    [
+    /* avoid parse error with comments */
+    #if(defined(__SDCC_VERSION_PATCH))
+	__SDCC_VERSION_PATCH
+    #elsif(defined(_SDCC_VERSION_PATCHLEVEL))
+	__SDCC_VERSION_PATCHLEVEL
+    #else
+	SDCC%10
+    #endif
+    ],,
+    AC_MSG_FAILURE([[[$0]] unknown sdcc patch level]))
+  ax_cv_[]_AC_LANG_ABBREV[]_compiler_version="$_ax_[]_AC_LANG_ABBREV[]_compiler_version_major.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_minor.$_ax_[]_AC_LANG_ABBREV[]_compiler_version_patch"
+  ])
+
+# main entry point
+AC_DEFUN([AX_COMPILER_VERSION],[dnl
+  AC_REQUIRE([AX_COMPILER_VENDOR])
+  AC_REQUIRE([AC_PROG_SED])
+  AC_CACHE_CHECK([for _AC_LANG compiler version],
+    ax_cv_[]_AC_LANG_ABBREV[]_compiler_version,
+    [ dnl
+      AS_CASE([$ax_cv_[]_AC_LANG_ABBREV[]_compiler_vendor],
+        [intel],[_AX_COMPILER_VERSION_INTEL],
+	[ibm],[_AX_COMPILER_VERSION_IBM],
+	[pathscale],[_AX_COMPILER_VERSION_PATHSCALE],
+	[clang],[_AX_COMPILER_VERSION_CLANG],
+	[cray],[_AX_COMPILER_VERSION_CRAY],
+	[fujitsu],[_AX_COMPILER_VERSION_FUJITSU],
+        [gnu],[_AX_COMPILER_VERSION_GNU],
+	[sun],[_AX_COMPILER_VERSION_SUN],
+	[hp],[_AX_COMPILER_VERSION_HP],
+	[dec],[_AX_COMPILER_VERSION_DEC],
+	[borland],[_AX_COMPILER_VERSION_BORLAND],
+	[comeau],[_AX_COMPILER_VERSION_COMEAU],
+	[kai],[_AX_COMPILER_VERSION_KAI],
+	[sgi],[_AX_COMPILER_VERSION_SGI],
+	[microsoft],[_AX_COMPILER_VERSION_MICROSOFT],
+	[metrowerks],[_AX_COMPILER_VERSION_METROWERKS],
+	[watcom],[_AX_COMPILER_VERSION_WATCOM],
+	[portland],[_AX_COMPILER_VERSION_PORTLAND],
+	[tcc],[_AX_COMPILER_VERSION_TCC],
+	[sdcc],[_AX_COMPILER_VERSION_SDCC],
+  	[ax_cv_[]_AC_LANG_ABBREV[]_compiler_version=""])
+    ])
+])
diff --git a/m4/ax_count_cpus.m4 b/m4/ax_count_cpus.m4
index d4f3d290f..5db892553 100644
--- a/m4/ax_count_cpus.m4
+++ b/m4/ax_count_cpus.m4
@@ -1,20 +1,24 @@
 # ===========================================================================
-#       http://www.gnu.org/software/autoconf-archive/ax_count_cpus.html
+#      https://www.gnu.org/software/autoconf-archive/ax_count_cpus.html
 # ===========================================================================
 #
 # SYNOPSIS
 #
-#   AX_COUNT_CPUS
+#   AX_COUNT_CPUS([ACTION-IF-DETECTED],[ACTION-IF-NOT-DETECTED])
 #
 # DESCRIPTION
 #
-#   Attempt to count the number of processors present on the machine. If the
-#   detection fails, then a value of 1 is assumed.
+#   Attempt to count the number of logical processor cores (including
+#   virtual and HT cores) currently available to use on the machine and
+#   place detected value in CPU_COUNT variable.
 #
-#   The value is placed in the CPU_COUNT variable.
+#   On successful detection, ACTION-IF-DETECTED is executed if present. If
+#   the detection fails, then ACTION-IF-NOT-DETECTED is triggered. The
+#   default ACTION-IF-NOT-DETECTED is to set CPU_COUNT to 1.
 #
 # LICENSE
 #
+#   Copyright (c) 2014,2016 Karlson2k (Evgeny Grin) <k2k@narod.ru>
 #   Copyright (c) 2012 Brian Aker <brian@tangent.org>
 #   Copyright (c) 2008 Michael Paul Bailey <jinxidoru@byu.net>
 #   Copyright (c) 2008 Christophe Tournayre <turn3r@users.sourceforge.net>
@@ -24,34 +28,74 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 10
+#serial 22
 
-  AC_DEFUN([AX_COUNT_CPUS],[
-      AC_REQUIRE([AC_CANONICAL_HOST])
-      AC_REQUIRE([AC_PROG_EGREP])
+  AC_DEFUN([AX_COUNT_CPUS],[dnl
+      AC_REQUIRE([AC_CANONICAL_HOST])dnl
+      AC_REQUIRE([AC_PROG_EGREP])dnl
       AC_MSG_CHECKING([the number of available CPUs])
       CPU_COUNT="0"
 
-      AS_CASE([$host_os],[
-        *darwin*],[
-        AS_IF([test -x /usr/sbin/sysctl],[
-          sysctl_a=`/usr/sbin/sysctl -a 2>/dev/null| grep -c hw.cpu`
-          AS_IF([test sysctl_a],[
-            CPU_COUNT=`/usr/sbin/sysctl -n hw.ncpu`
-            ])
-          ])],[
-        *linux*],[
-        AS_IF([test "x$CPU_COUNT" = "x0" -a -e /proc/cpuinfo],[
-          AS_IF([test "x$CPU_COUNT" = "x0" -a -e /proc/cpuinfo],[
-            CPU_COUNT=`$EGREP -c '^processor' /proc/cpuinfo`
-            ])
-          ])
-        ])
+      # Try generic methods
 
-      AS_IF([test "x$CPU_COUNT" = "x0"],[
-        CPU_COUNT="1"
-        AC_MSG_RESULT( [unable to detect (assuming 1)] )
-        ],[
-        AC_MSG_RESULT( $CPU_COUNT )
-        ])
-      ])
+      # 'getconf' is POSIX utility, but '_NPROCESSORS_ONLN' and
+      # 'NPROCESSORS_ONLN' are platform-specific
+      command -v getconf >/dev/null 2>&1 && \
+        CPU_COUNT=`getconf _NPROCESSORS_ONLN 2>/dev/null || getconf NPROCESSORS_ONLN 2>/dev/null` || CPU_COUNT="0"
+      AS_IF([[test "$CPU_COUNT" -gt "0" 2>/dev/null || ! command -v nproc >/dev/null 2>&1]],[[: # empty]],[dnl
+        # 'nproc' is part of GNU Coreutils and is widely available
+        CPU_COUNT=`OMP_NUM_THREADS='' nproc 2>/dev/null` || CPU_COUNT=`nproc 2>/dev/null` || CPU_COUNT="0"
+      ])dnl
+
+      AS_IF([[test "$CPU_COUNT" -gt "0" 2>/dev/null]],[[: # empty]],[dnl
+        # Try platform-specific preferred methods
+        AS_CASE([[$host_os]],dnl
+          [[*linux*]],[[CPU_COUNT=`lscpu -p 2>/dev/null | $EGREP -e '^@<:@0-9@:>@+,' -c` || CPU_COUNT="0"]],dnl
+          [[*darwin*]],[[CPU_COUNT=`sysctl -n hw.logicalcpu 2>/dev/null` || CPU_COUNT="0"]],dnl
+          [[freebsd*]],[[command -v sysctl >/dev/null 2>&1 && CPU_COUNT=`sysctl -n kern.smp.cpus 2>/dev/null` || CPU_COUNT="0"]],dnl
+          [[netbsd*]], [[command -v sysctl >/dev/null 2>&1 && CPU_COUNT=`sysctl -n hw.ncpuonline 2>/dev/null` || CPU_COUNT="0"]],dnl
+          [[solaris*]],[[command -v psrinfo >/dev/null 2>&1 && CPU_COUNT=`psrinfo 2>/dev/null | $EGREP -e '^@<:@0-9@:>@.*on-line' -c 2>/dev/null` || CPU_COUNT="0"]],dnl
+          [[mingw*]],[[CPU_COUNT=`ls -qpU1 /proc/registry/HKEY_LOCAL_MACHINE/HARDWARE/DESCRIPTION/System/CentralProcessor/ 2>/dev/null | $EGREP -e '^@<:@0-9@:>@+/' -c` || CPU_COUNT="0"]],dnl
+          [[msys*]],[[CPU_COUNT=`ls -qpU1 /proc/registry/HKEY_LOCAL_MACHINE/HARDWARE/DESCRIPTION/System/CentralProcessor/ 2>/dev/null | $EGREP -e '^@<:@0-9@:>@+/' -c` || CPU_COUNT="0"]],dnl
+          [[cygwin*]],[[CPU_COUNT=`ls -qpU1 /proc/registry/HKEY_LOCAL_MACHINE/HARDWARE/DESCRIPTION/System/CentralProcessor/ 2>/dev/null | $EGREP -e '^@<:@0-9@:>@+/' -c` || CPU_COUNT="0"]]dnl
+        )dnl
+      ])dnl
+
+      AS_IF([[test "$CPU_COUNT" -gt "0" 2>/dev/null || ! command -v sysctl >/dev/null 2>&1]],[[: # empty]],[dnl
+        # Try less preferred generic method
+        # 'hw.ncpu' exist on many platforms, but not on GNU/Linux
+        CPU_COUNT=`sysctl -n hw.ncpu 2>/dev/null` || CPU_COUNT="0"
+      ])dnl
+
+      AS_IF([[test "$CPU_COUNT" -gt "0" 2>/dev/null]],[[: # empty]],[dnl
+      # Try platform-specific fallback methods
+      # They can be less accurate and slower then preferred methods
+        AS_CASE([[$host_os]],dnl
+          [[*linux*]],[[CPU_COUNT=`$EGREP -e '^processor' -c /proc/cpuinfo 2>/dev/null` || CPU_COUNT="0"]],dnl
+          [[*darwin*]],[[CPU_COUNT=`system_profiler SPHardwareDataType 2>/dev/null | $EGREP -i -e 'number of cores:'|cut -d : -f 2 -s|tr -d ' '` || CPU_COUNT="0"]],dnl
+          [[freebsd*]],[[CPU_COUNT=`dmesg 2>/dev/null| $EGREP -e '^cpu@<:@0-9@:>@+: '|sort -u|$EGREP -e '^' -c` || CPU_COUNT="0"]],dnl
+          [[netbsd*]], [[CPU_COUNT=`command -v cpuctl >/dev/null 2>&1 && cpuctl list 2>/dev/null| $EGREP -e '^@<:@0-9@:>@+ .* online ' -c` || \
+                           CPU_COUNT=`dmesg 2>/dev/null| $EGREP -e '^cpu@<:@0-9@:>@+ at'|sort -u|$EGREP -e '^' -c` || CPU_COUNT="0"]],dnl
+          [[solaris*]],[[command -v kstat >/dev/null 2>&1 && CPU_COUNT=`kstat -m cpu_info -s state -p 2>/dev/null | $EGREP -c -e 'on-line'` || \
+                           CPU_COUNT=`kstat -m cpu_info 2>/dev/null | $EGREP -c -e 'module: cpu_info'` || CPU_COUNT="0"]],dnl
+          [[mingw*]],[AS_IF([[CPU_COUNT=`reg query 'HKLM\\Hardware\\Description\\System\\CentralProcessor' 2>/dev/null | $EGREP -e '\\\\@<:@0-9@:>@+$' -c`]],dnl
+                        [[: # empty]],[[test "$NUMBER_OF_PROCESSORS" -gt "0" 2>/dev/null && CPU_COUNT="$NUMBER_OF_PROCESSORS"]])],dnl
+          [[msys*]],[[test "$NUMBER_OF_PROCESSORS" -gt "0" 2>/dev/null && CPU_COUNT="$NUMBER_OF_PROCESSORS"]],dnl
+          [[cygwin*]],[[test "$NUMBER_OF_PROCESSORS" -gt "0" 2>/dev/null && CPU_COUNT="$NUMBER_OF_PROCESSORS"]]dnl
+        )dnl
+      ])dnl
+
+      AS_IF([[test "x$CPU_COUNT" != "x0" && test "$CPU_COUNT" -gt 0 2>/dev/null]],[dnl
+          AC_MSG_RESULT([[$CPU_COUNT]])
+          m4_ifvaln([$1],[$1],)dnl
+        ],[dnl
+          m4_ifval([$2],[dnl
+            AS_UNSET([[CPU_COUNT]])
+            AC_MSG_RESULT([[unable to detect]])
+            $2
+          ], [dnl
+            CPU_COUNT="1"
+            AC_MSG_RESULT([[unable to detect (assuming 1)]])
+          ])dnl
+        ])dnl
+      ])dnl
diff --git a/m4/ax_file_escapes.m4 b/m4/ax_file_escapes.m4
index f4c6a06ae..a86fdc326 100644
--- a/m4/ax_file_escapes.m4
+++ b/m4/ax_file_escapes.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#      http://www.gnu.org/software/autoconf-archive/ax_file_escapes.html
+#     https://www.gnu.org/software/autoconf-archive/ax_file_escapes.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -19,7 +19,7 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 7
+#serial 8
 
 AC_DEFUN([AX_FILE_ESCAPES],[
 AX_DOLLAR="\$"
diff --git a/m4/ax_print_to_file.m4 b/m4/ax_print_to_file.m4
index 5b9d1c391..8aa71120d 100644
--- a/m4/ax_print_to_file.m4
+++ b/m4/ax_print_to_file.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#     http://www.gnu.org/software/autoconf-archive/ax_print_to_file.html
+#     https://www.gnu.org/software/autoconf-archive/ax_print_to_file.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -19,7 +19,7 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 7
+#serial 8
 
 AC_DEFUN([AX_PRINT_TO_FILE],[
 AC_REQUIRE([AX_FILE_ESCAPES])
diff --git a/m4/visibility.m4 b/m4/visibility.m4
index 757154f33..7e9976475 100644
--- a/m4/visibility.m4
+++ b/m4/visibility.m4
@@ -1,5 +1,5 @@
 # visibility.m4 serial 5 (gettext-0.18.2)
-dnl Copyright (C) 2005, 2008, 2010-2014 Free Software Foundation, Inc.
+dnl Copyright (C) 2005, 2008, 2010-2018 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.
@@ -58,7 +58,7 @@ AC_DEFUN([gl_VISIBILITY],
              extern __attribute__((__visibility__("default"))) int exportedvar;
              extern __attribute__((__visibility__("hidden"))) int hiddenfunc (void);
              extern __attribute__((__visibility__("default"))) int exportedfunc (void);
-             int hiddenfunc (void) { return 0; }
+             void dummyfunc (void) {}
            ]],
            [[]])],
         [gl_cv_cc_visibility=yes],