cannam@95: dnl @synopsis AX_OPENMP([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
cannam@95: dnl @summary determine how to compile programs using OpenMP
cannam@95: dnl @category InstalledPackages
cannam@95: dnl
cannam@95: dnl This macro tries to find out how to compile programs that
cannam@95: dnl use OpenMP, a standard API and set of compiler directives for
cannam@95: dnl parallel programming (see http://www.openmp.org/).
cannam@95: dnl
cannam@95: dnl On success, it sets the OPENMP_CFLAGS/OPENMP_CXXFLAGS/OPENMP_FFLAGS
cannam@95: dnl output variable to the flag (e.g. -omp) used both to compile *and* link
cannam@95: dnl OpenMP programs in the current language.
cannam@95: dnl
cannam@95: dnl NOTE: You are assumed to not only compile your program with these
cannam@95: dnl flags, but also link it with them as well.
cannam@95: dnl
cannam@95: dnl If you want to compile everything with OpenMP, you should set:
cannam@95: dnl
cannam@95: dnl     CFLAGS="$CFLAGS $OPENMP_CFLAGS" 
cannam@95: dnl     #OR#  CXXFLAGS="$CXXFLAGS $OPENMP_CXXFLAGS" 
cannam@95: dnl     #OR#  FFLAGS="$FFLAGS $OPENMP_FFLAGS" 
cannam@95: dnl
cannam@95: dnl (depending on the selected language).
cannam@95: dnl
cannam@95: dnl The user can override the default choice by setting the corresponding
cannam@95: dnl environment variable (e.g. OPENMP_CFLAGS).
cannam@95: dnl
cannam@95: dnl ACTION-IF-FOUND is a list of shell commands to run if an OpenMP
cannam@95: dnl flag is found, and ACTION-IF-NOT-FOUND is a list of commands
cannam@95: dnl to run it if it is not found.  If ACTION-IF-FOUND is not specified,
cannam@95: dnl the default action will define HAVE_OPENMP.
cannam@95: dnl
cannam@95: dnl @version 2006-11-20
cannam@95: dnl @license GPLWithACException
cannam@95: dnl @author Steven G. Johnson <stevenj@alum.mit.edu>
cannam@95: 
cannam@95: AC_DEFUN([AX_OPENMP], [
cannam@95: AC_PREREQ(2.59) dnl for _AC_LANG_PREFIX
cannam@95: 
cannam@95: AC_CACHE_CHECK([for OpenMP flag of _AC_LANG compiler], ax_cv_[]_AC_LANG_ABBREV[]_openmp, [save[]_AC_LANG_PREFIX[]FLAGS=$[]_AC_LANG_PREFIX[]FLAGS
cannam@95: ax_cv_[]_AC_LANG_ABBREV[]_openmp=unknown
cannam@95: # Flags to try:  -fopenmp (gcc), -openmp (icc), -mp (SGI & PGI),
cannam@95: #                -xopenmp (Sun), -omp (Tru64), -qsmp=omp (AIX), none
cannam@95: ax_openmp_flags="-fopenmp -openmp -mp -xopenmp -omp -qsmp=omp none"
cannam@95: if test "x$OPENMP_[]_AC_LANG_PREFIX[]FLAGS" != x; then
cannam@95:   ax_openmp_flags="$OPENMP_[]_AC_LANG_PREFIX[]FLAGS $ax_openmp_flags"
cannam@95: fi
cannam@95: for ax_openmp_flag in $ax_openmp_flags; do
cannam@95:   case $ax_openmp_flag in
cannam@95:     none) []_AC_LANG_PREFIX[]FLAGS=$save[]_AC_LANG_PREFIX[] ;;
cannam@95:     *) []_AC_LANG_PREFIX[]FLAGS="$save[]_AC_LANG_PREFIX[]FLAGS $ax_openmp_flag" ;;
cannam@95:   esac
cannam@95:   AC_TRY_LINK_FUNC(omp_set_num_threads,
cannam@95: 	[ax_cv_[]_AC_LANG_ABBREV[]_openmp=$ax_openmp_flag; break])
cannam@95: done
cannam@95: []_AC_LANG_PREFIX[]FLAGS=$save[]_AC_LANG_PREFIX[]FLAGS
cannam@95: ])
cannam@95: if test "x$ax_cv_[]_AC_LANG_ABBREV[]_openmp" = "xunknown"; then
cannam@95:   m4_default([$2],:)
cannam@95: else
cannam@95:   if test "x$ax_cv_[]_AC_LANG_ABBREV[]_openmp" != "xnone"; then
cannam@95:     OPENMP_[]_AC_LANG_PREFIX[]FLAGS=$ax_cv_[]_AC_LANG_ABBREV[]_openmp
cannam@95:   fi
cannam@95:   m4_default([$1], [AC_DEFINE(HAVE_OPENMP,1,[Define if OpenMP is enabled])])
cannam@95: fi
cannam@95: AC_SUBST(OPENMP_[]_AC_LANG_PREFIX[]FLAGS)
cannam@95: ])dnl AX_OPENMP