2 dnl Copyright (C) 2007-2012 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_LONG_DOUBLE_VS_DOUBLE])
11 AC_REQUIRE([gl_FUNC_ISNANL]) dnl for ISNANL_LIBM
12 dnl Check whether it's declared.
13 dnl MacOS X 10.3 has ldexpl() in libc but doesn't declare it in <math.h>.
14 AC_CHECK_DECL([ldexpl], , [HAVE_DECL_LDEXPL=0], [[#include <math.h>]])
16 if test $HAVE_DECL_LDEXPL = 1; then
17 gl_CHECK_LDEXPL_NO_LIBM
18 if test $gl_cv_func_ldexpl_no_libm = no; then
19 AC_CACHE_CHECK([whether ldexpl() can be used with libm],
20 [gl_cv_func_ldexpl_in_libm],
28 [[return ldexpl (x, -1) > 0;]])],
29 [gl_cv_func_ldexpl_in_libm=yes],
30 [gl_cv_func_ldexpl_in_libm=no])
33 if test $gl_cv_func_ldexpl_in_libm = yes; then
37 if test $gl_cv_func_ldexpl_no_libm = yes \
38 || test $gl_cv_func_ldexpl_in_libm = yes; then
40 LIBS="$LIBS $LDEXPL_LIBM"
43 case "$gl_cv_func_ldexpl_works" in
44 *yes) gl_func_ldexpl=yes ;;
45 *) gl_func_ldexpl=no; REPLACE_LDEXPL=1 ;;
50 if test $gl_func_ldexpl = yes; then
51 AC_DEFINE([HAVE_LDEXPL], [1],
52 [Define if the ldexpl() function is available.])
55 if test $HAVE_DECL_LDEXPL = 0 || test $gl_func_ldexpl = no; then
56 dnl Find libraries needed to link lib/ldexpl.c.
57 if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
58 AC_REQUIRE([gl_FUNC_LDEXP])
59 LDEXPL_LIBM="$LDEXP_LIBM"
61 LDEXPL_LIBM="$ISNANL_LIBM"
64 AC_SUBST([LDEXPL_LIBM])
67 dnl Test whether ldexpl() can be used without linking with libm.
68 dnl Set gl_cv_func_ldexpl_no_libm to 'yes' or 'no' accordingly.
69 AC_DEFUN([gl_CHECK_LDEXPL_NO_LIBM],
71 AC_CACHE_CHECK([whether ldexpl() can be used without linking with libm],
72 [gl_cv_func_ldexpl_no_libm],
78 [[return ldexpl (x, -1) > 0;]])],
79 [gl_cv_func_ldexpl_no_libm=yes],
80 [gl_cv_func_ldexpl_no_libm=no])
84 dnl Test whether ldexpl() works on finite numbers (this fails on AIX 5.1
85 dnl and MacOS X 10.4/PowerPC).
86 AC_DEFUN([gl_FUNC_LDEXPL_WORKS],
88 AC_REQUIRE([AC_PROG_CC])
89 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
90 AC_CACHE_CHECK([whether ldexpl works], [gl_cv_func_ldexpl_works],
99 long double ldexpl (long double, int);
104 volatile long double x = 1.0;
105 volatile long double y = ldexpl (x, -1);
110 volatile long double x = 1.73205L;
111 volatile long double y = ldexpl (x, 0);
117 [gl_cv_func_ldexpl_works=yes],
118 [gl_cv_func_ldexpl_works=no],
122 aix | aix[3-6]*) gl_cv_func_ldexpl_works="guessing no";;
123 *) gl_cv_func_ldexpl_works="guessing yes";;