1 /* Macros for not-a-number.
2 Copyright (C) 2007-2020 Free Software Foundation, Inc.
3
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 3 of the License, or
7 (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <https://www.gnu.org/licenses/>. */
16
17
18 /* IBM z/OS supports both hexadecimal and IEEE floating-point formats. The
19 former does not support NaN and its isnan() implementation returns zero
20 for all values. */
21 #if defined __MVS__ && defined __IBMC__ && !defined __BFP__
22 # error "NaN is not supported with IBM's hexadecimal floating-point format; please re-compile with -qfloat=ieee"
23 #endif
24
25 /* NaNf () returns a 'float' not-a-number. */
26
27 /* The Compaq (ex-DEC) C 6.4 compiler and the Microsoft MSVC 9 compiler choke
28 on the expression 0.0 / 0.0. The IBM XL C compiler on z/OS complains.
29 PGI 16.10 complains. */
30 #if (defined __DECC || defined _MSC_VER \
31 || (defined __MVS__ && defined __IBMC__) \
32 || defined __PGI)
33 static float
NaNf()34 NaNf ()
35 {
36 static float zero = 0.0f;
37 return zero / zero;
38 }
39 #else
40 # define NaNf() (0.0f / 0.0f)
41 #endif
42
43
44 /* NaNd () returns a 'double' not-a-number. */
45
46 /* The Compaq (ex-DEC) C 6.4 compiler and the Microsoft MSVC 9 compiler choke
47 on the expression 0.0 / 0.0. The IBM XL C compiler on z/OS complains.
48 PGI 16.10 complains. */
49 #if (defined __DECC || defined _MSC_VER \
50 || (defined __MVS__ && defined __IBMC__) \
51 || defined __PGI)
52 static double
NaNd()53 NaNd ()
54 {
55 static double zero = 0.0;
56 return zero / zero;
57 }
58 #else
59 # define NaNd() (0.0 / 0.0)
60 #endif
61
62
63 /* NaNl () returns a 'long double' not-a-number. */
64
65 /* On Irix 6.5, gcc 3.4.3 can't compute compile-time NaN, and needs the
66 runtime type conversion.
67 The Microsoft MSVC 9 compiler chokes on the expression 0.0L / 0.0L.
68 The IBM XL C compiler on z/OS complains.
69 PGI 16.10 complains. */
70 #ifdef __sgi
NaNl()71 static long double NaNl ()
72 {
73 double zero = 0.0;
74 return zero / zero;
75 }
76 #elif defined _MSC_VER || (defined __MVS__ && defined __IBMC__) || defined __PGI
77 static long double
NaNl()78 NaNl ()
79 {
80 static long double zero = 0.0L;
81 return zero / zero;
82 }
83 #else
84 # define NaNl() (0.0L / 0.0L)
85 #endif
86