1 dnl Copyright (C) 1993-2006 Free Software Foundation, Inc.
2 dnl This file is free software, distributed under the terms of the GNU
3 dnl General Public License. As a special exception to the GNU General
4 dnl Public License, this file may be distributed as part of a program
5 dnl that contains a configuration script generated by Autoconf, under
6 dnl the same distribution terms as the rest of that program.
8 dnl From Bruno Haible, Marcus Daniels, Paul Eggert.
12 AC_DEFUN([CL_LONGDOUBLE],
13 [AC_CACHE_CHECK(for long double type, cl_cv_c_longdouble, [
17 { long double x = 2.7182818284590452354L; x = x*x; exit (x==0.0L); }
19 cl_cv_c_longdouble=yes, cl_cv_c_longdouble=no, [
20 dnl When cross-compiling, use the test from gnulib.
22 /* The Stardent Vistra knows sizeof(long double), but does not support it. */
23 long double foo = 0.0;
24 /* On Ultrix 4.3 cc, long double is 4 and double is 8. */
25 int array [2*(sizeof(long double) >= sizeof(double)) - 1];
26 ], , cl_cv_c_longdouble=yes, cl_cv_c_longdouble=no)])
28 if test $cl_cv_c_longdouble = yes; then
29 AC_DEFINE(HAVE_LONGDOUBLE, ,[Define if compiler supports long double type])