diff --git a/config/ax_compiler_vendor.m4 b/config/ax_compiler_vendor.m4
index 0256bbaf..039f99d2 100644
--- a/config/ax_compiler_vendor.m4
+++ b/config/ax_compiler_vendor.m4
@@ -8,15 +8,30 @@
 #
 # DESCRIPTION
 #
-#   Determine the vendor of the C/C++ compiler, e.g., gnu, intel, ibm, sun,
-#   hp, borland, comeau, dec, cray, kai, lcc, metrowerks, sgi, microsoft,
-#   watcom, etc. The vendor is returned in the cache variable
-#   $ax_cv_c_compiler_vendor for C and $ax_cv_cxx_compiler_vendor for C++.
+#   Determine the vendor of the C, C++ or Fortran compiler.  The vendor is
+#   returned in the cache variable $ax_cv_c_compiler_vendor for C,
+#   $ax_cv_cxx_compiler_vendor for C++ or $ax_cv_fc_compiler_vendor for
+#   (modern) Fortran.  The value is one of "intel", "ibm", "pathscale",
+#   "clang" (LLVM), "cray", "fujitsu", "sdcc", "sx", "nvhpc" (NVIDIA HPC
+#   Compiler), "portland" (PGI), "gnu" (GCC), "sun" (Oracle Developer
+#   Studio), "hp", "dec", "borland", "comeau", "kai", "lcc", "sgi",
+#   "microsoft", "metrowerks", "watcom", "tcc" (Tiny CC) or "unknown" (if
+#   the compiler cannot be determined).
+#
+#   To check for a Fortran compiler, you must first call AC_FC_PP_SRCEXT
+#   with an appropriate preprocessor-enabled extension.  For example:
+#
+#     AC_LANG_PUSH([Fortran])
+#     AC_PROG_FC
+#     AC_FC_PP_SRCEXT([F])
+#     AX_COMPILER_VENDOR
+#     AC_LANG_POP([Fortran])
 #
 # LICENSE
 #
 #   Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu>
 #   Copyright (c) 2008 Matteo Frigo
+#   Copyright (c) 2018-19 John Zaitseff <J.Zaitseff@zap.org.au>
 #
 #   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
@@ -44,45 +59,61 @@
 #   modified version of the Autoconf Macro, you may extend this special
 #   exception to the GPL to apply to your modified version as well.
 
-#serial 16
+#serial 32
+
+AC_DEFUN([AX_COMPILER_VENDOR], [dnl
+    AC_CACHE_CHECK([for _AC_LANG compiler vendor], ax_cv_[]_AC_LANG_ABBREV[]_compiler_vendor, [dnl
+	dnl  If you modify this list of vendors, please add similar support
+	dnl  to ax_compiler_version.m4 if at all possible.
+	dnl
+	dnl  Note: Do NOT check for GCC first since some other compilers
+	dnl  define __GNUC__ to remain compatible with it.  Compilers that
+	dnl  are very slow to start (such as Intel) are listed first.
+
+	vendors="
+		intel:		__ICC,__ECC,__INTEL_COMPILER
+		ibm:		__xlc__,__xlC__,__IBMC__,__IBMCPP__,__ibmxl__
+		pathscale:	__PATHCC__,__PATHSCALE__
+		clang:		__clang__
+		cray:		_CRAYC
+		fujitsu:	__FUJITSU
+		sdcc:		SDCC,__SDCC
+		sx:		_SX
+		nvhpc:		__NVCOMPILER
+		portland:	__PGI
+		gnu:		__GNUC__
+		sun:		__SUNPRO_C,__SUNPRO_CC,__SUNPRO_F90,__SUNPRO_F95
+		hp:		__HP_cc,__HP_aCC
+		dec:		__DECC,__DECCXX,__DECC_VER,__DECCXX_VER
+		borland:	__BORLANDC__,__CODEGEARC__,__TURBOC__
+		comeau:		__COMO__
+		kai:		__KCC
+		lcc:		__LCC__
+		sgi:		__sgi,sgi
+		microsoft:	_MSC_VER
+		metrowerks:	__MWERKS__
+		watcom:		__WATCOMC__
+		tcc:		__TINYC__
+		unknown:	UNKNOWN
+	"
+	for ventest in $vendors; do
+	    case $ventest in
+		*:)
+		    vendor=$ventest
+		    continue
+		    ;;
+		*)
+		    vencpp="defined("`echo $ventest | sed 's/,/) || defined(/g'`")"
+		    ;;
+	    esac
 
-AC_DEFUN([AX_COMPILER_VENDOR],
-[AC_CACHE_CHECK([for _AC_LANG compiler vendor], ax_cv_[]_AC_LANG_ABBREV[]_compiler_vendor,
-  dnl Please add if possible support to ax_compiler_version.m4
-  [# note: don't check for gcc first since some other compilers define __GNUC__
-  vendors="intel:     __ICC,__ECC,__INTEL_COMPILER
-           ibm:       __xlc__,__xlC__,__IBMC__,__IBMCPP__
-           pathscale: __PATHCC__,__PATHSCALE__
-           clang:     __clang__
-           cray:      _CRAYC
-           fujitsu:   __FUJITSU
-           gnu:       __GNUC__
-           sun:       __SUNPRO_C,__SUNPRO_CC
-           hp:        __HP_cc,__HP_aCC
-           dec:       __DECC,__DECCXX,__DECC_VER,__DECCXX_VER
-           borland:   __BORLANDC__,__CODEGEARC__,__TURBOC__
-           comeau:    __COMO__
-           kai:       __KCC
-           lcc:       __LCC__
-           sgi:       __sgi,sgi
-           microsoft: _MSC_VER
-           metrowerks: __MWERKS__
-           watcom:    __WATCOMC__
-           portland:  __PGI
-	   tcc:       __TINYC__
-           unknown:   UNKNOWN"
-  for ventest in $vendors; do
-    case $ventest in
-      *:) vendor=$ventest; continue ;;
-      *)  vencpp="defined("`echo $ventest | sed 's/,/) || defined(/g'`")" ;;
-    esac
-    AC_COMPILE_IFELSE([AC_LANG_PROGRAM(,[
-      #if !($vencpp)
-        thisisanerror;
-      #endif
-    ])], [break])
-  done
-  ax_cv_[]_AC_LANG_ABBREV[]_compiler_vendor=`echo $vendor | cut -d: -f1`
- ])
-])
+	    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], [[
+#if !($vencpp)
+      thisisanerror;
+#endif
+	    ]])], [break])
+	done
 
+	ax_cv_[]_AC_LANG_ABBREV[]_compiler_vendor=`echo $vendor | cut -d: -f1`
+    ])
+])dnl