1 /* A correct <float.h>. 2 3 Copyright (C) 2007-2012 Free Software Foundation, Inc. 4 5 This program is free software: you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program 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 General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <http://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 <http://lists.gnu.org/archive/html/bug-gnulib/2008-07/msg00063.html>. */ 66 #if defined __i386__ && defined __FreeBSD__ 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 3.3621031431120935E-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 union gl_long_double_union 97 { 98 struct { unsigned int lo; unsigned int hi; unsigned int exponent; } xd; 99 long double ld; 100 }; 101 extern const union gl_long_double_union gl_LDBL_MAX; 102 # define LDBL_MAX (gl_LDBL_MAX.ld) 103 /* Minimum e such that 10^e is in the range of normalized numbers. */ 104 # undef LDBL_MIN_10_EXP 105 # define LDBL_MIN_10_EXP (-4931) 106 /* Maximum e such that 10^e is in the range of representable finite numbers. */ 107 # undef LDBL_MAX_10_EXP 108 # define LDBL_MAX_10_EXP 4932 109 #endif 110 111 /* On AIX 7.1 with gcc 4.2, the values of LDBL_MIN_EXP, LDBL_MIN, LDBL_MAX are 112 wrong. 113 On Linux/PowerPC with gcc 4.4, the value of LDBL_MAX is wrong. */ 114 #if (defined _ARCH_PPC || defined _POWER) && defined _AIX && (LDBL_MANT_DIG == 106) && defined __GNUC__ 115 # undef LDBL_MIN_EXP 116 # define LDBL_MIN_EXP DBL_MIN_EXP 117 # undef LDBL_MIN_10_EXP 118 # define LDBL_MIN_10_EXP DBL_MIN_10_EXP 119 # undef LDBL_MIN 120 # define LDBL_MIN 2.22507385850720138309023271733240406422e-308L /* DBL_MIN = 2^-1022 */ 121 #endif 122 #if (defined _ARCH_PPC || defined _POWER) && (defined _AIX || defined __linux__) && (LDBL_MANT_DIG == 106) && defined __GNUC__ 123 # undef LDBL_MAX 124 /* LDBL_MAX is represented as { 0x7FEFFFFF, 0xFFFFFFFF, 0x7C8FFFFF, 0xFFFFFFFF }. 125 It is not easy to define: 126 #define LDBL_MAX 1.79769313486231580793728971405302307166e308L 127 is too small, whereas 128 #define LDBL_MAX 1.79769313486231580793728971405302307167e308L 129 is too large. Apparently a bug in GCC decimal-to-binary conversion. 130 Also, I can't get values larger than 131 #define LDBL63 ((long double) (1ULL << 63)) 132 #define LDBL882 (LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63) 133 #define LDBL945 (LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63) 134 #define LDBL1008 (LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63 * LDBL63) 135 #define LDBL_MAX (LDBL1008 * 65535.0L + LDBL945 * (long double) 9223372036821221375ULL + LDBL882 * (long double) 4611686018427387904ULL) 136 which is represented as { 0x7FEFFFFF, 0xFFFFFFFF, 0x7C8FFFFF, 0xF8000000 }. 137 So, define it like this through a reference to an external variable 138 139 const double LDBL_MAX[2] = { DBL_MAX, DBL_MAX / (double)134217728UL / (double)134217728UL }; 140 extern const long double LDBL_MAX; 141 142 or through a pointer cast 143 144 #define LDBL_MAX \ 145 (*(const long double *) (double[]) { DBL_MAX, DBL_MAX / (double)134217728UL / (double)134217728UL }) 146 147 Unfortunately, this is not a constant expression, and the latter expression 148 does not work well when GCC is optimizing.. */ 149 union gl_long_double_union 150 { 151 struct { double hi; double lo; } dd; 152 long double ld; 153 }; 154 extern const union gl_long_double_union gl_LDBL_MAX; 155 # define LDBL_MAX (gl_LDBL_MAX.ld) 156 #endif 157 158 /* On IRIX 6.5, with cc, the value of LDBL_MANT_DIG is wrong. 159 On IRIX 6.5, with gcc 4.2, the values of LDBL_MIN_EXP, LDBL_MIN, LDBL_EPSILON 160 are wrong. */ 161 #if defined __sgi && (LDBL_MANT_DIG >= 106) 162 # undef LDBL_MANT_DIG 163 # define LDBL_MANT_DIG 106 164 # if defined __GNUC__ 165 # undef LDBL_MIN_EXP 166 # define LDBL_MIN_EXP DBL_MIN_EXP 167 # undef LDBL_MIN_10_EXP 168 # define LDBL_MIN_10_EXP DBL_MIN_10_EXP 169 # undef LDBL_MIN 170 # define LDBL_MIN 2.22507385850720138309023271733240406422e-308L /* DBL_MIN = 2^-1022 */ 171 # undef LDBL_EPSILON 172 # define LDBL_EPSILON 2.46519032881566189191165176650870696773e-32L /* 2^-105 */ 173 # endif 174 #endif 175 176 #if @REPLACE_ITOLD@ 177 /* Pull in a function that fixes the 'int' to 'long double' conversion 178 of glibc 2.7. */ 179 extern 180 # ifdef __cplusplus 181 "C" 182 # endif 183 void _Qp_itoq (long double *, int); 184 static void (*_gl_float_fix_itold) (long double *, int) = _Qp_itoq; 185 #endif 186 187 #endif /* _@GUARD_PREFIX@_FLOAT_H */ 188 #endif /* _@GUARD_PREFIX@_FLOAT_H */ 189
