# =========================================================================== # https://www.gnu.org/software/autoconf-archive/ax_openmp.html # =========================================================================== # # SYNOPSIS # # AX_OPENMP([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]]) # # DESCRIPTION # # This macro tries to find out how to compile programs that use OpenMP a # standard API and set of compiler directives for parallel programming # (see http://www-unix.mcs/) # # On success, it sets the OPENMP_CFLAGS/OPENMP_CXXFLAGS/OPENMP_F77FLAGS # output variable to the flag (e.g. -omp) used both to compile *and* link # OpenMP programs in the current language. # # NOTE: You are assumed to not only compile your program with these flags, # but also link it with them as well. # # If you want to compile everything with OpenMP, you should set: # # CFLAGS="$CFLAGS $OPENMP_CFLAGS" # #OR# CXXFLAGS="$CXXFLAGS $OPENMP_CXXFLAGS" # #OR# FFLAGS="$FFLAGS $OPENMP_FFLAGS" # # (depending on the selected language). # # The user can override the default choice by setting the corresponding # environment variable (e.g. OPENMP_CFLAGS). # # ACTION-IF-FOUND is a list of shell commands to run if an OpenMP flag is # found, and ACTION-IF-NOT-FOUND is a list of commands to run it if it is # not found. If ACTION-IF-FOUND is not specified, the default action will # define HAVE_OPENMP. # # LICENSE # # Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu> # Copyright (c) 2015 John W. Peterson <jwpeterson@gmail.com> # Copyright (c) 2016 Nick R. Papior <nickpapior@gmail.com> # # 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 <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 # 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 13 AC_DEFUN([AX_OPENMP], [ AC_PREREQ([2.63]) dnl for _AC_LANG_PREFIX AC_CACHE_CHECK([for OpenMP flag of _AC_LANG compiler], ax_cv_[]_AC_LANG_ABBREV[]_openmp, [save[]_AC_LANG_PREFIX[]FLAGS=$[]_AC_LANG_PREFIX[]FLAGS ax_cv_[]_AC_LANG_ABBREV[]_openmp=unknown # Flags to try: -fopenmp (gcc), -mp (SGI & PGI), # -qopenmp (icc>=15), -openmp (icc), # -xopenmp (Sun), -omp (Tru64), # -qsmp=omp (AIX), # none ax_openmp_flags="-fopenmp -openmp -qopenmp -mp -xopenmp -omp -qsmp=omp none" if test "x$OPENMP_[]_AC_LANG_PREFIX[]FLAGS" != x; then ax_openmp_flags="$OPENMP_[]_AC_LANG_PREFIX[]FLAGS $ax_openmp_flags" fi for ax_openmp_flag in $ax_openmp_flags; do case $ax_openmp_flag in none) []_AC_LANG_PREFIX[]FLAGS=$save[]_AC_LANG_PREFIX[] ;; *) []_AC_LANG_PREFIX[]FLAGS="$save[]_AC_LANG_PREFIX[]FLAGS $ax_openmp_flag" ;; esac AC_LINK_IFELSE([AC_LANG_SOURCE([[ @%:@include <omp.h> static void parallel_fill(int * data, int n) { int i; @%:@pragma omp parallel for for (i = 0; i < n; ++i) data[i] = i; } int main() { int arr[100000]; omp_set_num_threads(2); parallel_fill(arr, 100000); return 0; } ]])],[ax_cv_[]_AC_LANG_ABBREV[]_openmp=$ax_openmp_flag; break],[]) done []_AC_LANG_PREFIX[]FLAGS=$save[]_AC_LANG_PREFIX[]FLAGS ]) if test "x$ax_cv_[]_AC_LANG_ABBREV[]_openmp" = "xunknown"; then m4_default([$2],:) else if test "x$ax_cv_[]_AC_LANG_ABBREV[]_openmp" != "xnone"; then OPENMP_[]_AC_LANG_PREFIX[]FLAGS=$ax_cv_[]_AC_LANG_ABBREV[]_openmp fi m4_default([$1], [AC_DEFINE(HAVE_OPENMP,1,[Define if OpenMP is enabled])]) fi ])dnl AX_OPENMP