Commit | Line | Data |
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3d458a81 | 1 | # isnanf.m4 serial 14 |
f0007cad | 2 | dnl Copyright (C) 2007-2012 Free Software Foundation, Inc. |
2e65b52f LC |
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. | |
6 | ||
7 | dnl Check how to get or define isnanf(). | |
8 | ||
9 | AC_DEFUN([gl_FUNC_ISNANF], | |
10 | [ | |
11 | AC_REQUIRE([gl_MATH_H_DEFAULTS]) | |
12 | ISNANF_LIBM= | |
13 | gl_HAVE_ISNANF_NO_LIBM | |
14 | if test $gl_cv_func_isnanf_no_libm = no; then | |
15 | gl_HAVE_ISNANF_IN_LIBM | |
16 | if test $gl_cv_func_isnanf_in_libm = yes; then | |
17 | ISNANF_LIBM=-lm | |
18 | fi | |
19 | fi | |
3d458a81 | 20 | dnl The variable gl_func_isnanf set here is used by isnan.m4. |
2e65b52f LC |
21 | if test $gl_cv_func_isnanf_no_libm = yes \ |
22 | || test $gl_cv_func_isnanf_in_libm = yes; then | |
23 | save_LIBS="$LIBS" | |
24 | LIBS="$LIBS $ISNANF_LIBM" | |
25 | gl_ISNANF_WORKS | |
26 | LIBS="$save_LIBS" | |
27 | case "$gl_cv_func_isnanf_works" in | |
28 | *yes) gl_func_isnanf=yes ;; | |
29 | *) gl_func_isnanf=no; ISNANF_LIBM= ;; | |
30 | esac | |
31 | else | |
32 | gl_func_isnanf=no | |
33 | fi | |
34 | if test $gl_func_isnanf != yes; then | |
35 | HAVE_ISNANF=0 | |
2e65b52f LC |
36 | fi |
37 | AC_SUBST([ISNANF_LIBM]) | |
38 | ]) | |
39 | ||
40 | dnl Check how to get or define isnanf() without linking with libm. | |
41 | ||
42 | AC_DEFUN([gl_FUNC_ISNANF_NO_LIBM], | |
43 | [ | |
44 | gl_HAVE_ISNANF_NO_LIBM | |
45 | if test $gl_cv_func_isnanf_no_libm = yes; then | |
46 | gl_ISNANF_WORKS | |
47 | fi | |
48 | if test $gl_cv_func_isnanf_no_libm = yes \ | |
49 | && { case "$gl_cv_func_isnanf_works" in | |
50 | *yes) true;; | |
51 | *) false;; | |
52 | esac | |
53 | }; then | |
3d458a81 | 54 | gl_func_isnanf_no_libm=yes |
2e65b52f LC |
55 | AC_DEFINE([HAVE_ISNANF_IN_LIBC], [1], |
56 | [Define if the isnan(float) function is available in libc.]) | |
57 | else | |
3d458a81 | 58 | gl_func_isnanf_no_libm=no |
2e65b52f LC |
59 | fi |
60 | ]) | |
61 | ||
3d458a81 AW |
62 | dnl Prerequisites of replacement isnanf definition. It does not need -lm. |
63 | AC_DEFUN([gl_PREREQ_ISNANF], | |
2e65b52f | 64 | [ |
2e65b52f LC |
65 | gl_FLOAT_EXPONENT_LOCATION |
66 | ]) | |
67 | ||
68 | dnl Test whether isnanf() can be used without libm. | |
69 | AC_DEFUN([gl_HAVE_ISNANF_NO_LIBM], | |
70 | [ | |
71 | AC_CACHE_CHECK([whether isnan(float) can be used without linking with libm], | |
72 | [gl_cv_func_isnanf_no_libm], | |
73 | [ | |
74 | AC_LINK_IFELSE( | |
75 | [AC_LANG_PROGRAM( | |
76 | [[#include <math.h> | |
77 | #if __GNUC__ >= 4 | |
78 | # undef isnanf | |
79 | # define isnanf(x) __builtin_isnanf ((float)(x)) | |
80 | #elif defined isnan | |
81 | # undef isnanf | |
82 | # define isnanf(x) isnan ((float)(x)) | |
83 | #endif | |
84 | float x;]], | |
85 | [[return isnanf (x);]])], | |
86 | [gl_cv_func_isnanf_no_libm=yes], | |
87 | [gl_cv_func_isnanf_no_libm=no]) | |
88 | ]) | |
89 | ]) | |
90 | ||
91 | dnl Test whether isnanf() can be used with libm. | |
92 | AC_DEFUN([gl_HAVE_ISNANF_IN_LIBM], | |
93 | [ | |
94 | AC_CACHE_CHECK([whether isnan(float) can be used with libm], | |
95 | [gl_cv_func_isnanf_in_libm], | |
96 | [ | |
97 | save_LIBS="$LIBS" | |
98 | LIBS="$LIBS -lm" | |
99 | AC_LINK_IFELSE( | |
100 | [AC_LANG_PROGRAM( | |
101 | [[#include <math.h> | |
102 | #if __GNUC__ >= 4 | |
103 | # undef isnanf | |
104 | # define isnanf(x) __builtin_isnanf ((float)(x)) | |
105 | #elif defined isnan | |
106 | # undef isnanf | |
107 | # define isnanf(x) isnan ((float)(x)) | |
108 | #endif | |
109 | float x;]], | |
110 | [[return isnanf (x);]])], | |
111 | [gl_cv_func_isnanf_in_libm=yes], | |
112 | [gl_cv_func_isnanf_in_libm=no]) | |
113 | LIBS="$save_LIBS" | |
114 | ]) | |
115 | ]) | |
116 | ||
117 | dnl Test whether isnanf() rejects Infinity (this fails on Solaris 2.5.1), | |
118 | dnl recognizes a NaN (this fails on IRIX 6.5 with cc), and recognizes a NaN | |
119 | dnl with in-memory representation 0x7fbfffff (this fails on IRIX 6.5). | |
120 | AC_DEFUN([gl_ISNANF_WORKS], | |
121 | [ | |
122 | AC_REQUIRE([AC_PROG_CC]) | |
123 | AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles | |
124 | AC_REQUIRE([gl_FLOAT_EXPONENT_LOCATION]) | |
125 | AC_CACHE_CHECK([whether isnan(float) works], [gl_cv_func_isnanf_works], | |
126 | [ | |
127 | AC_RUN_IFELSE( | |
128 | [AC_LANG_SOURCE([[ | |
129 | #include <math.h> | |
130 | #if __GNUC__ >= 4 | |
131 | # undef isnanf | |
132 | # define isnanf(x) __builtin_isnanf ((float)(x)) | |
133 | #elif defined isnan | |
134 | # undef isnanf | |
135 | # define isnanf(x) isnan ((float)(x)) | |
136 | #endif | |
137 | /* The Compaq (ex-DEC) C 6.4 compiler chokes on the expression 0.0 / 0.0. */ | |
138 | #ifdef __DECC | |
139 | static float | |
140 | NaN () | |
141 | { | |
142 | static float zero = 0.0f; | |
143 | return zero / zero; | |
144 | } | |
145 | #else | |
146 | # define NaN() (0.0f / 0.0f) | |
147 | #endif | |
148 | #define NWORDS \ | |
149 | ((sizeof (float) + sizeof (unsigned int) - 1) / sizeof (unsigned int)) | |
150 | typedef union { unsigned int word[NWORDS]; float value; } memory_float; | |
151 | int main() | |
152 | { | |
0f00f2c3 | 153 | int result = 0; |
2e65b52f LC |
154 | |
155 | if (isnanf (1.0f / 0.0f)) | |
0f00f2c3 | 156 | result |= 1; |
2e65b52f LC |
157 | |
158 | if (!isnanf (NaN ())) | |
0f00f2c3 | 159 | result |= 2; |
2e65b52f LC |
160 | |
161 | #if defined FLT_EXPBIT0_WORD && defined FLT_EXPBIT0_BIT | |
162 | /* The isnanf function should be immune against changes in the sign bit and | |
163 | in the mantissa bits. The xor operation twiddles a bit that can only be | |
164 | a sign bit or a mantissa bit. */ | |
165 | if (FLT_EXPBIT0_WORD == 0 && FLT_EXPBIT0_BIT > 0) | |
166 | { | |
0f00f2c3 LC |
167 | memory_float m; |
168 | ||
2e65b52f LC |
169 | m.value = NaN (); |
170 | /* Set the bits below the exponent to 01111...111. */ | |
171 | m.word[0] &= -1U << FLT_EXPBIT0_BIT; | |
172 | m.word[0] |= 1U << (FLT_EXPBIT0_BIT - 1) - 1; | |
173 | if (!isnanf (m.value)) | |
0f00f2c3 | 174 | result |= 4; |
2e65b52f LC |
175 | } |
176 | #endif | |
177 | ||
0f00f2c3 | 178 | return result; |
2e65b52f LC |
179 | }]])], |
180 | [gl_cv_func_isnanf_works=yes], | |
181 | [gl_cv_func_isnanf_works=no], | |
182 | [case "$host_os" in | |
183 | irix* | solaris*) gl_cv_func_isnanf_works="guessing no";; | |
184 | *) gl_cv_func_isnanf_works="guessing yes";; | |
185 | esac | |
186 | ]) | |
187 | ]) | |
188 | ]) |