2 dnl Copyright (C) 2010 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
7 AC_DEFUN([gl_FUNC_EXPL],
9 AC_REQUIRE([gl_MATH_H_DEFAULTS])
10 dnl Persuade glibc <math.h> to declare expl().
11 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
14 AC_CACHE_CHECK([whether expl() can be used without linking with libm],
15 [gl_cv_func_expl_no_libm],
17 AC_TRY_LINK([#ifndef __NO_MATH_INLINES
18 # define __NO_MATH_INLINES 1 /* for glibc */
22 [return expl (x) > 1.5;],
23 [gl_cv_func_expl_no_libm=yes],
24 [gl_cv_func_expl_no_libm=no])
26 if test $gl_cv_func_expl_no_libm = no; then
27 AC_CACHE_CHECK([whether expl() can be used with libm],
28 [gl_cv_func_expl_in_libm],
32 AC_TRY_LINK([#ifndef __NO_MATH_INLINES
33 # define __NO_MATH_INLINES 1 /* for glibc */
37 [return expl (x) > 1.5;],
38 [gl_cv_func_expl_in_libm=yes],
39 [gl_cv_func_expl_in_libm=no])
42 if test $gl_cv_func_expl_in_libm = yes; then
46 if test $gl_cv_func_expl_no_libm = yes \
47 || test $gl_cv_func_expl_in_libm = yes; then
48 dnl Also check whether it's declared.
49 dnl MacOS X 10.3 has expl() in libc but doesn't declare it in <math.h>.
50 AC_CHECK_DECL([expl], , [HAVE_DECL_EXPL=0], [#include <math.h>])
55 AC_REQUIRE([gl_FUNC_FLOORL])
56 EXPL_LIBM="$FLOORL_LIBM"