AC_DEFUN([AX_DETECT_GMP], [

AC_DEFINE([USE_GMP_FOR_MP], [], [use gmp to implement isl_int])

AX_SUBMODULE(gmp,system|build,system)

case "$with_gmp" in

system)

	if test "x$with_gmp_prefix" != "x"; then

		isl_configure_args="$isl_configure_args --with-gmp=$with_gmp_prefix"

		MP_CPPFLAGS="-I$with_gmp_prefix/include"

		MP_LDFLAGS="-L$with_gmp_prefix/lib"

	fi

	MP_LIBS=-lgmp

	SAVE_CPPFLAGS="$CPPFLAGS"

	SAVE_LDFLAGS="$LDFLAGS"

	SAVE_LIBS="$LIBS"

	CPPFLAGS="$MP_CPPFLAGS $CPPFLAGS"

	LDFLAGS="$MP_LDFLAGS $LDFLAGS"

	LIBS="$MP_LIBS $LIBS"

	AC_CHECK_HEADER([gmp.h], [], [AC_ERROR([gmp.h header not found])])

	AC_CHECK_LIB([gmp], [main], [], [AC_ERROR([gmp library not found])])

	AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <gmp.h>]], [[

		mpz_t n, d;

		if (mpz_divisible_p(n, d))

			mpz_divexact_ui(n, n, 4);

	]])], [], [AC_ERROR([gmp library too old])])

	CPPFLAGS="$SAVE_CPPFLAGS"

	LDFLAGS="$SAVE_LDFLAGS"

	LIBS="$SAVE_LIBS"

	;;

build)

	MP_CPPFLAGS="-I$gmp_srcdir -I$with_gmp_builddir"

	MP_LIBS="$with_gmp_builddir/libgmp.la"

	;;

esac

SAVE_CPPFLAGS="$CPPFLAGS"

SAVE_LDFLAGS="$LDFLAGS"

SAVE_LIBS="$LIBS"

CPPFLAGS="$MP_CPPFLAGS $CPPFLAGS"

LDFLAGS="$MP_LDFLAGS $LDFLAGS"

LIBS="$MP_LIBS $LIBS"

need_get_memory_functions=false

AC_CHECK_DECLS(mp_get_memory_functions,[],[

	need_get_memory_functions=true

],[#include <gmp.h>])

CPPFLAGS="$SAVE_CPPFLAGS"

LDFLAGS="$SAVE_LDFLAGS"

LIBS="$SAVE_LIBS"

AM_CONDITIONAL(NEED_GET_MEMORY_FUNCTIONS, test x$need_get_memory_functions = xtrue)

])