2 dnl Copyright (C) 2007-2010 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_FREXPL],
9 AC_REQUIRE([gl_MATH_H_DEFAULTS])
10 dnl Check whether it's declared.
11 dnl MacOS X 10.3 has frexpl() in libc but doesn't declare it in <math.h>.
12 AC_CHECK_DECL([frexpl], , [HAVE_DECL_FREXPL=0], [#include <math.h>])
14 if test $HAVE_DECL_FREXPL = 1; then
15 AC_CACHE_CHECK([whether frexpl() can be used without linking with libm],
16 [gl_cv_func_frexpl_no_libm],
18 AC_TRY_LINK([#include <math.h>
20 [int e; return frexpl (x, &e) > 0;],
21 [gl_cv_func_frexpl_no_libm=yes],
22 [gl_cv_func_frexpl_no_libm=no])
24 if test $gl_cv_func_frexpl_no_libm = no; then
25 AC_CACHE_CHECK([whether frexpl() can be used with libm],
26 [gl_cv_func_frexpl_in_libm],
30 AC_TRY_LINK([#include <math.h>
32 [int e; return frexpl (x, &e) > 0;],
33 [gl_cv_func_frexpl_in_libm=yes],
34 [gl_cv_func_frexpl_in_libm=no])
37 if test $gl_cv_func_frexpl_in_libm = yes; then
41 if test $gl_cv_func_frexpl_no_libm = yes \
42 || test $gl_cv_func_frexpl_in_libm = yes; then
44 LIBS="$LIBS $FREXPL_LIBM"
47 case "$gl_cv_func_frexpl_works" in
48 *yes) gl_func_frexpl=yes ;;
49 *) gl_func_frexpl=no; REPLACE_FREXPL=1; FREXPL_LIBM= ;;
54 if test $gl_func_frexpl = yes; then
55 AC_DEFINE([HAVE_FREXPL], [1],
56 [Define if the frexpl() function is available.])
59 if test $HAVE_DECL_FREXPL = 0 || test $gl_func_frexpl = no; then
62 AC_SUBST([FREXPL_LIBM])
65 AC_DEFUN([gl_FUNC_FREXPL_NO_LIBM],
67 AC_REQUIRE([gl_MATH_H_DEFAULTS])
68 dnl Check whether it's declared.
69 dnl MacOS X 10.3 has frexpl() in libc but doesn't declare it in <math.h>.
70 AC_CHECK_DECL([frexpl], , [HAVE_DECL_FREXPL=0], [#include <math.h>])
71 if test $HAVE_DECL_FREXPL = 1; then
72 AC_CACHE_CHECK([whether frexpl() can be used without linking with libm],
73 [gl_cv_func_frexpl_no_libm],
75 AC_TRY_LINK([#include <math.h>
77 [int e; return frexpl (x, &e) > 0;],
78 [gl_cv_func_frexpl_no_libm=yes],
79 [gl_cv_func_frexpl_no_libm=no])
81 if test $gl_cv_func_frexpl_no_libm = yes; then
83 case "$gl_cv_func_frexpl_works" in
84 *yes) gl_func_frexpl_no_libm=yes ;;
85 *) gl_func_frexpl_no_libm=no; REPLACE_FREXPL=1 ;;
88 gl_func_frexpl_no_libm=no
89 dnl Set REPLACE_FREXPL here because the system may have frexpl in libm.
92 if test $gl_func_frexpl_no_libm = yes; then
93 AC_DEFINE([HAVE_FREXPL_IN_LIBC], [1],
94 [Define if the frexpl() function is available in libc.])
97 if test $HAVE_DECL_FREXPL = 0 || test $gl_func_frexpl_no_libm = no; then
102 dnl Test whether frexpl() works on finite numbers (this fails on
103 dnl MacOS X 10.4/PowerPC, on AIX 5.1, and on BeOS), on denormalized numbers
104 dnl (this fails on MacOS X 10.5/i386), and also on infinite numbers (this
105 dnl fails e.g. on IRIX 6.5 and mingw).
106 AC_DEFUN([gl_FUNC_FREXPL_WORKS],
108 AC_REQUIRE([AC_PROG_CC])
109 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
110 AC_CACHE_CHECK([whether frexpl works], [gl_cv_func_frexpl_works],
115 /* Override the values of <float.h>, like done in float.in.h. */
116 #if defined __i386__ && (defined __BEOS__ || defined __OpenBSD__)
118 # define LDBL_MIN_EXP (-16381)
120 extern long double frexpl (long double, int *);
123 volatile long double x;
124 /* Test on finite numbers that fails on AIX 5.1. */
132 /* Test on finite numbers that fails on MacOS X 10.4, because its frexpl
133 function returns an invalid (incorrectly normalized) value: it returns
134 y = { 0x3fe028f5, 0xc28f5c28, 0x3c9eb851, 0xeb851eb8 }
135 but the correct result is
136 0.505L = { 0x3fe028f5, 0xc28f5c29, 0xbc547ae1, 0x47ae1480 } */
140 long double y = frexpl (x, &exp);
141 if (!(exp == 1 && y == 0.505L))
144 /* Test on large finite numbers. This fails on BeOS at i = 16322, while
145 LDBL_MAX_EXP = 16384.
146 In the loop end test, we test x against Infinity, rather than comparing
147 i with LDBL_MAX_EXP, because BeOS <float.h> has a wrong LDBL_MAX_EXP. */
150 for (i = 1, x = 1.0L; x != x + x; i++, x *= 2.0L)
158 /* Test on denormalized numbers. */
161 for (i = 1, x = 1.0L; i >= LDBL_MIN_EXP; i--, x *= 0.5L)
166 long double y = frexpl (x, &exp);
167 /* On machines with IEEE854 arithmetic: x = 1.68105e-4932,
168 exp = -16382, y = 0.5. On MacOS X 10.5: exp = -16384, y = 0.5. */
169 if (exp != LDBL_MIN_EXP - 1)
173 /* Test on infinite numbers. */
177 long double y = frexpl (x, &exp);
182 }], [gl_cv_func_frexpl_works=yes], [gl_cv_func_frexpl_works=no],
184 aix* | beos* | darwin* | irix* | mingw* | pw*)
185 gl_cv_func_frexpl_works="guessing no";;
186 *) gl_cv_func_frexpl_works="guessing yes";;