2 dnl Copyright (C) 2007-2011 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_LDEXPL],
9 AC_REQUIRE([gl_MATH_H_DEFAULTS])
10 AC_REQUIRE([gl_FUNC_ISNANL]) dnl for ISNANL_LIBM
11 dnl Check whether it's declared.
12 dnl MacOS X 10.3 has ldexpl() in libc but doesn't declare it in <math.h>.
13 AC_CHECK_DECL([ldexpl], , [HAVE_DECL_LDEXPL=0], [#include <math.h>])
15 if test $HAVE_DECL_LDEXPL = 1; then
16 gl_CHECK_LDEXPL_NO_LIBM
17 if test $gl_cv_func_ldexpl_no_libm = no; then
18 AC_CACHE_CHECK([whether ldexpl() can be used with libm],
19 [gl_cv_func_ldexpl_in_libm],
27 [[return ldexpl (x, -1) > 0;]])],
28 [gl_cv_func_ldexpl_in_libm=yes],
29 [gl_cv_func_ldexpl_in_libm=no])
32 if test $gl_cv_func_ldexpl_in_libm = yes; then
36 if test $gl_cv_func_ldexpl_no_libm = yes \
37 || test $gl_cv_func_ldexpl_in_libm = yes; then
39 LIBS="$LIBS $LDEXPL_LIBM"
42 case "$gl_cv_func_ldexpl_works" in
43 *yes) gl_func_ldexpl=yes ;;
44 *) gl_func_ldexpl=no; REPLACE_LDEXPL=1 ;;
49 if test $gl_func_ldexpl = yes; then
50 AC_DEFINE([HAVE_LDEXPL], [1],
51 [Define if the ldexpl() function is available.])
54 if test $HAVE_DECL_LDEXPL = 0 || test $gl_func_ldexpl = no; then
55 dnl Find libraries needed to link lib/ldexpl.c.
56 LDEXPL_LIBM="$ISNANL_LIBM"
58 AC_SUBST([LDEXPL_LIBM])
61 dnl Test whether ldexpl() can be used without linking with libm.
62 dnl Set gl_cv_func_ldexpl_no_libm to 'yes' or 'no' accordingly.
63 AC_DEFUN([gl_CHECK_LDEXPL_NO_LIBM],
65 AC_CACHE_CHECK([whether ldexpl() can be used without linking with libm],
66 [gl_cv_func_ldexpl_no_libm],
72 [[return ldexpl (x, -1) > 0;]])],
73 [gl_cv_func_ldexpl_no_libm=yes],
74 [gl_cv_func_ldexpl_no_libm=no])
78 dnl Test whether ldexpl() works on finite numbers (this fails on AIX 5.1
79 dnl and MacOS X 10.4/PowerPC).
80 AC_DEFUN([gl_FUNC_LDEXPL_WORKS],
82 AC_REQUIRE([AC_PROG_CC])
83 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
84 AC_CACHE_CHECK([whether ldexpl works], [gl_cv_func_ldexpl_works],
89 extern long double ldexpl (long double, int);
94 volatile long double x = 1.0;
95 volatile long double y = ldexpl (x, -1);
100 volatile long double x = 1.73205L;
101 volatile long double y = ldexpl (x, 0);
107 [gl_cv_func_ldexpl_works=yes],
108 [gl_cv_func_ldexpl_works=no],
112 aix | aix[3-6]*) gl_cv_func_ldexpl_works="guessing no";;
113 *) gl_cv_func_ldexpl_works="guessing yes";;