gcc/ginclude/float.h

   1 /* Copyright (C) 2002-2014 Free Software Foundation, Inc.
   2
   3 This file is part of GCC.
   4
   5 GCC 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, or (at your option)
   8 any later version.
   9
  10 GCC 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 Under Section 7 of GPL version 3, you are granted additional
  16 permissions described in the GCC Runtime Library Exception, version
  17 3.1, as published by the Free Software Foundation.
  18
  19 You should have received a copy of the GNU General Public License and
  20 a copy of the GCC Runtime Library Exception along with this program;
  21 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  22 <http://www.gnu.org/licenses/>.  */
  23
  24 /*
  25  * ISO C Standard:  5.2.4.2.2  Characteristics of floating types <float.h>
  26  */
  27
  28 #ifndef _FLOAT_H___
  29 #define _FLOAT_H___
  30
  31 /* Radix of exponent representation, b. */
  32 #undef FLT_RADIX
  33 #define FLT_RADIX       __FLT_RADIX__
  34
  35 /* Number of base-FLT_RADIX digits in the significand, p.  */
  36 #undef FLT_MANT_DIG
  37 #undef DBL_MANT_DIG
  38 #undef LDBL_MANT_DIG
  39 #define FLT_MANT_DIG    __FLT_MANT_DIG__
  40 #define DBL_MANT_DIG    __DBL_MANT_DIG__
  41 #define LDBL_MANT_DIG   __LDBL_MANT_DIG__
  42
  43 /* Number of decimal digits, q, such that any floating-point number with q
  44    decimal digits can be rounded into a floating-point number with p radix b
  45    digits and back again without change to the q decimal digits,
  46
  47         p * log10(b)                    if b is a power of 10
  48         floor((p - 1) * log10(b))       otherwise
  49 */
  50 #undef FLT_DIG
  51 #undef DBL_DIG
  52 #undef LDBL_DIG
  53 #define FLT_DIG         __FLT_DIG__
  54 #define DBL_DIG         __DBL_DIG__
  55 #define LDBL_DIG        __LDBL_DIG__
  56
  57 /* Minimum int x such that FLT_RADIX**(x-1) is a normalized float, emin */
  58 #undef FLT_MIN_EXP
  59 #undef DBL_MIN_EXP
  60 #undef LDBL_MIN_EXP
  61 #define FLT_MIN_EXP     __FLT_MIN_EXP__
  62 #define DBL_MIN_EXP     __DBL_MIN_EXP__
  63 #define LDBL_MIN_EXP    __LDBL_MIN_EXP__
  64
  65 /* Minimum negative integer such that 10 raised to that power is in the
  66    range of normalized floating-point numbers,
  67
  68         ceil(log10(b) * (emin - 1))
  69 */
  70 #undef FLT_MIN_10_EXP
  71 #undef DBL_MIN_10_EXP
  72 #undef LDBL_MIN_10_EXP
  73 #define FLT_MIN_10_EXP  __FLT_MIN_10_EXP__
  74 #define DBL_MIN_10_EXP  __DBL_MIN_10_EXP__
  75 #define LDBL_MIN_10_EXP __LDBL_MIN_10_EXP__
  76
  77 /* Maximum int x such that FLT_RADIX**(x-1) is a representable float, emax.  */
  78 #undef FLT_MAX_EXP
  79 #undef DBL_MAX_EXP
  80 #undef LDBL_MAX_EXP
  81 #define FLT_MAX_EXP     __FLT_MAX_EXP__
  82 #define DBL_MAX_EXP     __DBL_MAX_EXP__
  83 #define LDBL_MAX_EXP    __LDBL_MAX_EXP__
  84
  85 /* Maximum integer such that 10 raised to that power is in the range of
  86    representable finite floating-point numbers,
  87
  88         floor(log10((1 - b**-p) * b**emax))
  89 */
  90 #undef FLT_MAX_10_EXP
  91 #undef DBL_MAX_10_EXP
  92 #undef LDBL_MAX_10_EXP
  93 #define FLT_MAX_10_EXP  __FLT_MAX_10_EXP__
  94 #define DBL_MAX_10_EXP  __DBL_MAX_10_EXP__
  95 #define LDBL_MAX_10_EXP __LDBL_MAX_10_EXP__
  96
  97 /* Maximum representable finite floating-point number,
  98
  99         (1 - b**-p) * b**emax
 100 */
 101 #undef FLT_MAX
 102 #undef DBL_MAX
 103 #undef LDBL_MAX
 104 #define FLT_MAX         __FLT_MAX__
 105 #define DBL_MAX         __DBL_MAX__
 106 #define LDBL_MAX        __LDBL_MAX__
 107
 108 /* The difference between 1 and the least value greater than 1 that is
 109    representable in the given floating point type, b**1-p.  */
 110 #undef FLT_EPSILON
 111 #undef DBL_EPSILON
 112 #undef LDBL_EPSILON
 113 #define FLT_EPSILON     __FLT_EPSILON__
 114 #define DBL_EPSILON     __DBL_EPSILON__
 115 #define LDBL_EPSILON    __LDBL_EPSILON__
 116
 117 /* Minimum normalized positive floating-point number, b**(emin - 1).  */
 118 #undef FLT_MIN
 119 #undef DBL_MIN
 120 #undef LDBL_MIN
 121 #define FLT_MIN         __FLT_MIN__
 122 #define DBL_MIN         __DBL_MIN__
 123 #define LDBL_MIN        __LDBL_MIN__
 124
 125 /* Addition rounds to 0: zero, 1: nearest, 2: +inf, 3: -inf, -1: unknown.  */
 126 /* ??? This is supposed to change with calls to fesetround in <fenv.h>.  */
 127 #undef FLT_ROUNDS
 128 #define FLT_ROUNDS 1
 129
 130 #if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
 131 /* The floating-point expression evaluation method.
 132         -1  indeterminate
 133          0  evaluate all operations and constants just to the range and
 134             precision of the type
 135          1  evaluate operations and constants of type float and double
 136             to the range and precision of the double type, evaluate
 137             long double operations and constants to the range and
 138             precision of the long double type
 139          2  evaluate all operations and constants to the range and
 140             precision of the long double type
 141
 142    ??? This ought to change with the setting of the fp control word;
 143    the value provided by the compiler assumes the widest setting.  */
 144 #undef FLT_EVAL_METHOD
 145 #define FLT_EVAL_METHOD __FLT_EVAL_METHOD__
 146
 147 /* Number of decimal digits, n, such that any floating-point number in the
 148    widest supported floating type with pmax radix b digits can be rounded
 149    to a floating-point number with n decimal digits and back again without
 150    change to the value,
 151
 152         pmax * log10(b)                 if b is a power of 10
 153         ceil(1 + pmax * log10(b))       otherwise
 154 */
 155 #undef DECIMAL_DIG
 156 #define DECIMAL_DIG     __DECIMAL_DIG__
 157
 158 #endif /* C99 */
 159
 160 #if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
 161 /* Versions of DECIMAL_DIG for each floating-point type.  */
 162 #undef FLT_DECIMAL_DIG
 163 #undef DBL_DECIMAL_DIG
 164 #undef LDBL_DECIMAL_DIG
 165 #define FLT_DECIMAL_DIG         __FLT_DECIMAL_DIG__
 166 #define DBL_DECIMAL_DIG         __DBL_DECIMAL_DIG__
 167 #define LDBL_DECIMAL_DIG        __DECIMAL_DIG__
 168
 169 /* Whether types support subnormal numbers.  */
 170 #undef FLT_HAS_SUBNORM
 171 #undef DBL_HAS_SUBNORM
 172 #undef LDBL_HAS_SUBNORM
 173 #define FLT_HAS_SUBNORM         __FLT_HAS_DENORM__
 174 #define DBL_HAS_SUBNORM         __DBL_HAS_DENORM__
 175 #define LDBL_HAS_SUBNORM        __LDBL_HAS_DENORM__
 176
 177 /* Minimum positive values, including subnormals.  */
 178 #undef FLT_TRUE_MIN
 179 #undef DBL_TRUE_MIN
 180 #undef LDBL_TRUE_MIN
 181 #if __FLT_HAS_DENORM__
 182 #define FLT_TRUE_MIN    __FLT_DENORM_MIN__
 183 #else
 184 #define FLT_TRUE_MIN    __FLT_MIN__
 185 #endif
 186 #if __DBL_HAS_DENORM__
 187 #define DBL_TRUE_MIN    __DBL_DENORM_MIN__
 188 #else
 189 #define DBL_TRUE_MIN    __DBL_MIN__
 190 #endif
 191 #if __LDBL_HAS_DENORM__
 192 #define LDBL_TRUE_MIN   __LDBL_DENORM_MIN__
 193 #else
 194 #define LDBL_TRUE_MIN   __LDBL_MIN__
 195 #endif
 196
 197 #endif /* C11 */
 198
 199 #ifdef __STDC_WANT_DEC_FP__
 200 /* Draft Technical Report 24732, extension for decimal floating-point
 201    arithmetic: Characteristic of decimal floating types <float.h>.  */
 202
 203 /* Number of base-FLT_RADIX digits in the significand, p.  */
 204 #undef DEC32_MANT_DIG
 205 #undef DEC64_MANT_DIG
 206 #undef DEC128_MANT_DIG
 207 #define DEC32_MANT_DIG  __DEC32_MANT_DIG__
 208 #define DEC64_MANT_DIG  __DEC64_MANT_DIG__
 209 #define DEC128_MANT_DIG __DEC128_MANT_DIG__
 210
 211 /* Minimum exponent. */
 212 #undef DEC32_MIN_EXP
 213 #undef DEC64_MIN_EXP
 214 #undef DEC128_MIN_EXP
 215 #define DEC32_MIN_EXP   __DEC32_MIN_EXP__
 216 #define DEC64_MIN_EXP   __DEC64_MIN_EXP__
 217 #define DEC128_MIN_EXP  __DEC128_MIN_EXP__
 218
 219 /* Maximum exponent. */
 220 #undef DEC32_MAX_EXP
 221 #undef DEC64_MAX_EXP
 222 #undef DEC128_MAX_EXP
 223 #define DEC32_MAX_EXP   __DEC32_MAX_EXP__
 224 #define DEC64_MAX_EXP   __DEC64_MAX_EXP__
 225 #define DEC128_MAX_EXP  __DEC128_MAX_EXP__
 226
 227 /* Maximum representable finite decimal floating-point number
 228    (there are 6, 15, and 33 9s after the decimal points respectively). */
 229 #undef DEC32_MAX
 230 #undef DEC64_MAX
 231 #undef DEC128_MAX
 232 #define DEC32_MAX   __DEC32_MAX__
 233 #define DEC64_MAX   __DEC64_MAX__
 234 #define DEC128_MAX  __DEC128_MAX__
 235
 236 /* The difference between 1 and the least value greater than 1 that is
 237    representable in the given floating point type. */
 238 #undef DEC32_EPSILON
 239 #undef DEC64_EPSILON
 240 #undef DEC128_EPSILON
 241 #define DEC32_EPSILON   __DEC32_EPSILON__
 242 #define DEC64_EPSILON   __DEC64_EPSILON__
 243 #define DEC128_EPSILON  __DEC128_EPSILON__
 244
 245 /* Minimum normalized positive floating-point number. */
 246 #undef DEC32_MIN
 247 #undef DEC64_MIN
 248 #undef DEC128_MIN
 249 #define DEC32_MIN       __DEC32_MIN__
 250 #define DEC64_MIN       __DEC64_MIN__
 251 #define DEC128_MIN      __DEC128_MIN__
 252
 253 /* Minimum subnormal positive floating-point number. */
 254 #undef DEC32_SUBNORMAL_MIN
 255 #undef DEC64_SUBNORMAL_MIN
 256 #undef DEC128_SUBNORMAL_MIN
 257 #define DEC32_SUBNORMAL_MIN       __DEC32_SUBNORMAL_MIN__
 258 #define DEC64_SUBNORMAL_MIN       __DEC64_SUBNORMAL_MIN__
 259 #define DEC128_SUBNORMAL_MIN      __DEC128_SUBNORMAL_MIN__
 260
 261 /* The floating-point expression evaluation method.
 262          -1  indeterminate
 263          0  evaluate all operations and constants just to the range and
 264             precision of the type
 265          1  evaluate operations and constants of type _Decimal32
 266             and _Decimal64 to the range and precision of the _Decimal64
 267             type, evaluate _Decimal128 operations and constants to the
 268             range and precision of the _Decimal128 type;
 269          2  evaluate all operations and constants to the range and
 270             precision of the _Decimal128 type.  */
 271
 272 #undef DEC_EVAL_METHOD
 273 #define DEC_EVAL_METHOD __DEC_EVAL_METHOD__
 274
 275 #endif /* __STDC_WANT_DEC_FP__ */
 276
 277 #endif /* _FLOAT_H___ */