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1 /* A correct <float.h>.
2
3 Copyright (C) 2007-2021 Free Software Foundation, Inc.
4
5 This file is free software: you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 2.1 of the
8 License, or (at your option) any later version.
9
10 This file is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
17
18 #ifndef _@GUARD_PREFIX@_FLOAT_H
19
20 #if __GNUC__ >= 3
21 @PRAGMA_SYSTEM_HEADER@
22 #endif
23 @PRAGMA_COLUMNS@
24
25 /* The include_next requires a split double-inclusion guard. */
26 #@INCLUDE_NEXT@ @NEXT_FLOAT_H@
27
28 #ifndef _@GUARD_PREFIX@_FLOAT_H
29 #define _@GUARD_PREFIX@_FLOAT_H
30
31 /* 'long double' properties. */
32
33 #if defined __i386__ && (defined __BEOS__ || defined __OpenBSD__)
34 /* Number of mantissa units, in base FLT_RADIX. */
35 # undef LDBL_MANT_DIG
36 # define LDBL_MANT_DIG 64
37 /* Number of decimal digits that is sufficient for representing a number. */
38 # undef LDBL_DIG
39 # define LDBL_DIG 18
40 /* x-1 where x is the smallest representable number > 1. */
41 # undef LDBL_EPSILON
42 # define LDBL_EPSILON 1.0842021724855044340E-19L
43 /* Minimum e such that FLT_RADIX^(e-1) is a normalized number. */
44 # undef LDBL_MIN_EXP
45 # define LDBL_MIN_EXP (-16381)
46 /* Maximum e such that FLT_RADIX^(e-1) is a representable finite number. */
47 # undef LDBL_MAX_EXP
48 # define LDBL_MAX_EXP 16384
49 /* Minimum positive normalized number. */
50 # undef LDBL_MIN
51 # define LDBL_MIN 3.3621031431120935063E-4932L
52 /* Maximum representable finite number. */
53 # undef LDBL_MAX
54 # define LDBL_MAX 1.1897314953572317650E+4932L
55 /* Minimum e such that 10^e is in the range of normalized numbers. */
56 # undef LDBL_MIN_10_EXP
57 # define LDBL_MIN_10_EXP (-4931)
58 /* Maximum e such that 10^e is in the range of representable finite numbers. */
59 # undef LDBL_MAX_10_EXP
60 # define LDBL_MAX_10_EXP 4932
61 #endif
62
63 /* On FreeBSD/x86 6.4, the 'long double' type really has only 53 bits of
64 precision in the compiler but 64 bits of precision at runtime. See
65 <https://lists.gnu.org/r/bug-gnulib/2008-07/msg00063.html>. */
66 #if defined __i386__ && (defined __FreeBSD__ || defined __DragonFly__)
67 /* Number of mantissa units, in base FLT_RADIX. */
68 # undef LDBL_MANT_DIG
69 # define LDBL_MANT_DIG 64
70 /* Number of decimal digits that is sufficient for representing a number. */
71 # undef LDBL_DIG
72 # define LDBL_DIG 18
73 /* x-1 where x is the smallest representable number > 1. */
74 # undef LDBL_EPSILON
75 # define LDBL_EPSILON 1.084202172485504434007452800869941711426e-19L /* 2^-63 */
76 /* Minimum e such that FLT_RADIX^(e-1) is a normalized number. */
77 # undef LDBL_MIN_EXP
78 # define LDBL_MIN_EXP (-16381)
79 /* Maximum e such that FLT_RADIX^(e-1) is a representable finite number. */
80 # undef LDBL_MAX_EXP
81 # define LDBL_MAX_EXP 16384
82 /* Minimum positive normalized number. */
83 # undef LDBL_MIN
84 # define LDBL_MIN 3.362103143112093506262677817321752E-4932L /* = 0x1p-16382L */
85 /* Maximum representable finite number. */
86 # undef LDBL_MAX
87 /* LDBL_MAX is represented as { 0xFFFFFFFF, 0xFFFFFFFF, 32766 }.
88 But the largest literal that GCC allows us to write is
89 0x0.fffffffffffff8p16384L = { 0xFFFFF800, 0xFFFFFFFF, 32766 }.
90 So, define it like this through a reference to an external variable
91
92 const unsigned int LDBL_MAX[3] = { 0xFFFFFFFF, 0xFFFFFFFF, 32766 };
93 extern const long double LDBL_MAX;
94
95 Unfortunately, this is not a constant expression. */
96 # if !GNULIB_defined_long_double_union
97 union gl_long_double_union
98 {
99 struct { unsigned int lo; unsigned int hi; unsigned int exponent; } xd;
100 long double ld;
101 };
102 # define GNULIB_defined_long_double_union 1
103 # endif
104 extern const union gl_long_double_union gl_LDBL_MAX;
105 # define LDBL_MAX (gl_LDBL_MAX.ld)
106 /* Minimum e such that 10^e is in the range of normalized numbers. */
107 # undef LDBL_MIN_10_EXP
108 # define LDBL_MIN_10_EXP (-4931)
109 /* Maximum e such that 10^e is in the range of representable finite numbers. */
110 # undef LDBL_MAX_10_EXP
111 # define LDBL_MAX_10_EXP 4932
112 #endif
113
114 /* On AIX 7.1 with gcc 4.2, the values of LDBL_MIN_EXP, LDBL_MIN, LDBL_MAX are
115 wrong.
116 On Linux/PowerPC with gcc 4.4, the value of LDBL_MAX is wrong. */
117 #if (defined _ARCH_PPC || defined _POWER) && defined _AIX && (LDBL_MANT_DIG == 106) && defined __GNUC__
118 # undef LDBL_MIN_EXP
119 # define LDBL_MIN_EXP DBL_MIN_EXP
120 # undef LDBL_MIN_10_EXP
121 # define LDBL_MIN_10_EXP DBL_MIN_10_EXP
122 # undef LDBL_MIN
123 # define LDBL_MIN 2.22507385850720138309023271733240406422e-308L /* DBL_MIN = 2^-1022 */
124 #endif
125 #if (defined _ARCH_PPC || defined _POWER) && (defined _AIX || defined __linux__) && (LDBL_MANT_DIG == 106) && defined __GNUC__
126 # undef LDBL_MAX
127 /* LDBL_MAX is represented as { 0x7FEFFFFF, 0xFFFFFFFF, 0x7C8FFFFF, 0xFFFFFFFF }.
128 It is not easy to define:
129 #define LDBL_MAX 1.79769313486231580793728971405302307166e308L
130 is too small, whereas
131 #define LDBL_MAX 1.79769313486231580793728971405302307167e308L
132 is too large. Apparently a bug in GCC decimal-to-binary conversion.
133 Also, I can't get values larger than
134 #define LDBL63 ((long double) (1ULL << 63))
135 #define LDBL882 (LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63)
136 #define LDBL945 (LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63)
137 #define LDBL1008 (LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63)
138 #define LDBL_MAX (LDBL1008 * 65535.0L + LDBL945 * (long double) 9223372036821221375ULL + LDBL882 * (long double) 4611686018427387904ULL)
139 which is represented as { 0x7FEFFFFF, 0xFFFFFFFF, 0x7C8FFFFF, 0xF8000000 }.
140 So, define it like this through a reference to an external variable
141
142 const double LDBL_MAX[2] = { DBL_MAX, DBL_MAX / (double)134217728UL / (double)134217728UL };
143 extern const long double LDBL_MAX;
144
145 or through a pointer cast
146
147 #define LDBL_MAX \
148 (*(const long double *) (double[]) { DBL_MAX, DBL_MAX / (double)134217728UL / (double)134217728UL })
149
150 Unfortunately, this is not a constant expression, and the latter expression
151 does not work well when GCC is optimizing.. */
152 # if !GNULIB_defined_long_double_union
153 union gl_long_double_union
154 {
155 struct { double hi; double lo; } dd;
156 long double ld;
157 };
158 # define GNULIB_defined_long_double_union 1
159 # endif
160 extern const union gl_long_double_union gl_LDBL_MAX;
161 # define LDBL_MAX (gl_LDBL_MAX.ld)
162 #endif
163
164 /* On IRIX 6.5, with cc, the value of LDBL_MANT_DIG is wrong.
165 On IRIX 6.5, with gcc 4.2, the values of LDBL_MIN_EXP, LDBL_MIN, LDBL_EPSILON
166 are wrong. */
167 #if defined __sgi && (LDBL_MANT_DIG >= 106)
168 # undef LDBL_MANT_DIG
169 # define LDBL_MANT_DIG 106
170 # if defined __GNUC__
171 # undef LDBL_MIN_EXP
172 # define LDBL_MIN_EXP DBL_MIN_EXP
173 # undef LDBL_MIN_10_EXP
174 # define LDBL_MIN_10_EXP DBL_MIN_10_EXP
175 # undef LDBL_MIN
176 # define LDBL_MIN 2.22507385850720138309023271733240406422e-308L /* DBL_MIN = 2^-1022 */
177 # undef LDBL_EPSILON
178 # define LDBL_EPSILON 2.46519032881566189191165176650870696773e-32L /* 2^-105 */
179 # endif
180 #endif
181
182 #if @REPLACE_ITOLD@
183 /* Pull in a function that fixes the 'int' to 'long double' conversion
184 of glibc 2.7. */
185 extern
186 # ifdef __cplusplus
187 "C"
188 # endif
189 void _Qp_itoq (long double *, int);
190 static void (*_gl_float_fix_itold) (long double *, int) = _Qp_itoq;
191 #endif
192
193 #endif /* _@GUARD_PREFIX@_FLOAT_H */
194 #endif /* _@GUARD_PREFIX@_FLOAT_H */
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