From 4882b0a3d10bc5b7a7a71ad9cfc5f63c7a4186bd Mon Sep 17 00:00:00 2001
From: "Kurt A. O'Hearn" <ohearnku@cse.msu.edu>
Date: Wed, 7 Sep 2016 13:41:04 -0400
Subject: [PATCH] Autotools: add compiler vendor-specific optimization flags.

---
 m4/ax_compiler_vendor.m4 | 87 +++++++++++++++++++++++++++++++++++++++
 sPuReMD/Makefile.am      |  2 -
 sPuReMD/aclocal.m4       | 88 ++++++++++++++++++++++++++++++++++++++++
 sPuReMD/configure.ac     | 10 ++++-
 4 files changed, 184 insertions(+), 3 deletions(-)
 create mode 100644 m4/ax_compiler_vendor.m4

diff --git a/m4/ax_compiler_vendor.m4 b/m4/ax_compiler_vendor.m4
new file mode 100644
index 00000000..39ca3c0f
--- /dev/null
+++ b/m4/ax_compiler_vendor.m4
@@ -0,0 +1,87 @@
+# ===========================================================================
+#    http://www.gnu.org/software/autoconf-archive/ax_compiler_vendor.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_COMPILER_VENDOR
+#
+# 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++.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu>
+#   Copyright (c) 2008 Matteo Frigo
+#
+#   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 3 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 General
+#   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/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 15
+
+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`
+ ])
+])
diff --git a/sPuReMD/Makefile.am b/sPuReMD/Makefile.am
index e4f0c7b9..84f237b0 100644
--- a/sPuReMD/Makefile.am
+++ b/sPuReMD/Makefile.am
@@ -1,5 +1,3 @@
-AM_CFLAGS += -Wall -O3 -funroll-loops -fstrict-aliasing
-
 bin_PROGRAMS = bin/spuremd
 bin_spuremd_SOURCES = src/ffield.c src/grid.c src/list.c src/lookup.c src/print_utils.c \
 		  src/reset_utils.c src/restart.c src/random.c src/tool_box.c src/traj.c \
diff --git a/sPuReMD/aclocal.m4 b/sPuReMD/aclocal.m4
index f3018f6c..be5a4fa3 100644
--- a/sPuReMD/aclocal.m4
+++ b/sPuReMD/aclocal.m4
@@ -20,6 +20,94 @@ You have another version of autoconf.  It may work, but is not guaranteed to.
 If you have problems, you may need to regenerate the build system entirely.
 To do so, use the procedure documented by the package, typically 'autoreconf'.])])
 
+# ===========================================================================
+#    http://www.gnu.org/software/autoconf-archive/ax_compiler_vendor.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_COMPILER_VENDOR
+#
+# 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++.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu>
+#   Copyright (c) 2008 Matteo Frigo
+#
+#   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 3 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 General
+#   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/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 15
+
+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`
+ ])
+])
+
 # Copyright (C) 2002-2014 Free Software Foundation, Inc.
 #
 # This file is free software; the Free Software Foundation
diff --git a/sPuReMD/configure.ac b/sPuReMD/configure.ac
index 1ffd7f0a..f2cd0b82 100644
--- a/sPuReMD/configure.ac
+++ b/sPuReMD/configure.ac
@@ -44,6 +44,15 @@ AC_FUNC_MALLOC
 AC_FUNC_STRTOD
 AC_CHECK_FUNCS([gettimeofday memset])
 
+# Check for compiler vendor
+AX_COMPILER_VENDOR
+if test "x$ax_cv_c_compiler_vendor" = "xgnu"; then
+	CFLAGS="$CFLAGS -Wall -O3 -funroll-loops -fstrict-aliasing"
+fi
+if test "x$ax_cv_c_compiler_vendor" = "xintel"; then
+	CFLAGS="$CFLAGS -fast -Mipa=fast,inline"
+fi
+
 # Check for OpenMP support.
 if test "x$BUILD_OPENMP" = "xyes"; then
 	AC_OPENMP
@@ -55,7 +64,6 @@ if test "x$BUILD_OPENMP" = "xyes"; then
 	  -----------------------------------------------])
 	else
 		AC_SUBST(AM_CFLAGS, "$OPENMP_CFLAGS")
-		AC_SUBST(AM_CPPFLAGS, "$OPENMP_CFLAGS")
 	fi
 fi
 
-- 
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