1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
|
# frexpl.m4 serial 24
dnl Copyright (C) 2007-2024 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
AC_DEFUN([gl_FUNC_FREXPL],
[
AC_REQUIRE([gl_MATH_H_DEFAULTS])
AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
dnl Persuade glibc <math.h> to declare frexpl().
AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
dnl Check whether it's declared.
dnl Mac OS X 10.3 has frexpl() in libc but doesn't declare it in <math.h>.
AC_CHECK_DECL([frexpl], , [HAVE_DECL_FREXPL=0], [[#include <math.h>]])
FREXPL_LIBM=
if test $HAVE_DECL_FREXPL = 1; then
gl_CHECK_FREXPL_NO_LIBM
if test $gl_cv_func_frexpl_no_libm = no; then
AC_CACHE_CHECK([whether frexpl() can be used with libm],
[gl_cv_func_frexpl_in_libm],
[
saved_LIBS="$LIBS"
LIBS="$LIBS -lm"
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[[#include <math.h>
long double x;]],
[[int e; return frexpl (x, &e) > 0;]])],
[gl_cv_func_frexpl_in_libm=yes],
[gl_cv_func_frexpl_in_libm=no])
LIBS="$saved_LIBS"
])
if test $gl_cv_func_frexpl_in_libm = yes; then
FREXPL_LIBM=-lm
fi
fi
if test $gl_cv_func_frexpl_no_libm = yes \
|| test $gl_cv_func_frexpl_in_libm = yes; then
saved_LIBS="$LIBS"
LIBS="$LIBS $FREXPL_LIBM"
gl_FUNC_FREXPL_WORKS
LIBS="$saved_LIBS"
case "$gl_cv_func_frexpl_works" in
*yes) gl_func_frexpl=yes ;;
*) gl_func_frexpl=no; REPLACE_FREXPL=1 ;;
esac
else
gl_func_frexpl=no
fi
if test $gl_func_frexpl = yes; then
AC_DEFINE([HAVE_FREXPL], [1],
[Define if the frexpl() function is available.])
fi
fi
if test $HAVE_DECL_FREXPL = 0 || test $gl_func_frexpl = no; then
dnl Find libraries needed to link lib/frexpl.c.
if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
AC_REQUIRE([gl_FUNC_FREXP])
FREXPL_LIBM="$FREXP_LIBM"
else
FREXPL_LIBM=
fi
fi
AC_SUBST([FREXPL_LIBM])
])
AC_DEFUN([gl_FUNC_FREXPL_NO_LIBM],
[
AC_REQUIRE([gl_MATH_H_DEFAULTS])
AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
dnl Check whether it's declared.
dnl Mac OS X 10.3 has frexpl() in libc but doesn't declare it in <math.h>.
AC_CHECK_DECL([frexpl], , [HAVE_DECL_FREXPL=0], [[#include <math.h>]])
if test $HAVE_DECL_FREXPL = 1; then
gl_CHECK_FREXPL_NO_LIBM
if test $gl_cv_func_frexpl_no_libm = yes; then
gl_FUNC_FREXPL_WORKS
case "$gl_cv_func_frexpl_works" in
*yes) gl_func_frexpl_no_libm=yes ;;
*) gl_func_frexpl_no_libm=no; REPLACE_FREXPL=1 ;;
esac
else
gl_func_frexpl_no_libm=no
dnl Set REPLACE_FREXPL here because the system may have frexpl in libm.
REPLACE_FREXPL=1
fi
if test $gl_func_frexpl_no_libm = yes; then
AC_DEFINE([HAVE_FREXPL_IN_LIBC], [1],
[Define if the frexpl() function is available in libc.])
fi
fi
])
dnl Test whether frexpl() can be used without linking with libm.
dnl Set gl_cv_func_frexpl_no_libm to 'yes' or 'no' accordingly.
AC_DEFUN([gl_CHECK_FREXPL_NO_LIBM],
[
AC_CACHE_CHECK([whether frexpl() can be used without linking with libm],
[gl_cv_func_frexpl_no_libm],
[
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[[#include <math.h>
long double x;]],
[[int e; return frexpl (x, &e) > 0;]])],
[gl_cv_func_frexpl_no_libm=yes],
[gl_cv_func_frexpl_no_libm=no])
])
])
dnl Test whether frexpl() works on finite numbers (this fails on
dnl Mac OS X 10.4/PowerPC, on AIX 5.1, and on BeOS), on denormalized numbers
dnl (this fails on Mac OS X 10.5/i386), and also on infinite numbers (this
dnl fails e.g. on IRIX 6.5 and mingw).
AC_DEFUN([gl_FUNC_FREXPL_WORKS],
[
AC_REQUIRE([AC_PROG_CC])
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
AC_CACHE_CHECK([whether frexpl works], [gl_cv_func_frexpl_works],
[
AC_RUN_IFELSE(
[AC_LANG_SOURCE([[
#include <float.h>
#include <math.h>
/* Override the values of <float.h>, like done in float.in.h. */
#if defined __i386__ && (defined __BEOS__ || defined __OpenBSD__)
# undef LDBL_MIN_EXP
# define LDBL_MIN_EXP (-16381)
#endif
#if defined __i386__ && (defined __FreeBSD__ || defined __DragonFly__)
# undef LDBL_MIN_EXP
# define LDBL_MIN_EXP (-16381)
#endif
#if (defined _ARCH_PPC || defined _POWER) && defined _AIX && (LDBL_MANT_DIG == 106) && defined __GNUC__
# undef LDBL_MIN_EXP
# define LDBL_MIN_EXP DBL_MIN_EXP
#endif
#if defined __sgi && (LDBL_MANT_DIG >= 106)
# if defined __GNUC__
# undef LDBL_MIN_EXP
# define LDBL_MIN_EXP DBL_MIN_EXP
# endif
#endif
extern
#ifdef __cplusplus
"C"
#endif
long double frexpl (long double, int *);
long double zero = 0.0L;
int main()
{
int result = 0;
volatile long double x;
/* Test on finite numbers that fails on AIX 5.1. */
x = 16.0L;
{
int exp = -9999;
frexpl (x, &exp);
if (exp != 5)
result |= 1;
}
/* Test on finite numbers that fails on Mac OS X 10.4, because its frexpl
function returns an invalid (incorrectly normalized) value: it returns
y = { 0x3fe028f5, 0xc28f5c28, 0x3c9eb851, 0xeb851eb8 }
but the correct result is
0.505L = { 0x3fe028f5, 0xc28f5c29, 0xbc547ae1, 0x47ae1480 } */
x = 1.01L;
{
int exp = -9999;
long double y = frexpl (x, &exp);
if (!(exp == 1 && y == 0.505L))
result |= 2;
}
/* Test on large finite numbers. This fails on BeOS at i = 16322, while
LDBL_MAX_EXP = 16384.
In the loop end test, we test x against Infinity, rather than comparing
i with LDBL_MAX_EXP, because BeOS <float.h> has a wrong LDBL_MAX_EXP. */
{
int i;
for (i = 1, x = 1.0L; x != x + x; i++, x *= 2.0L)
{
int exp = -9999;
frexpl (x, &exp);
if (exp != i)
{
result |= 4;
break;
}
}
}
/* Test on denormalized numbers. */
{
int i;
for (i = 1, x = 1.0L; i >= LDBL_MIN_EXP; i--, x *= 0.5L)
;
if (x > 0.0L)
{
int exp;
long double y = frexpl (x, &exp);
/* On machines with IEEE854 arithmetic: x = 1.68105e-4932,
exp = -16382, y = 0.5. On Mac OS X 10.5: exp = -16384, y = 0.5. */
if (exp != LDBL_MIN_EXP - 1)
result |= 8;
}
}
/* Test on infinite numbers. */
/* The Microsoft MSVC 14 compiler chokes on the expression 1.0 / 0.0. */
x = 1.0L / zero;
{
int exp;
long double y = frexpl (x, &exp);
if (y != x)
result |= 16;
}
return result;
}]])],
[gl_cv_func_frexpl_works=yes],
[gl_cv_func_frexpl_works=no],
[
changequote(,)dnl
case "$host_os" in
aix | aix[3-6]* | beos* | darwin* | irix* | mingw* | windows* | pw*)
gl_cv_func_frexpl_works="guessing no";;
*) gl_cv_func_frexpl_works="guessing yes";;
esac
changequote([,])dnl
])
])
])
|
