| 1 | /* Supplemental information about the floating-point formats. |
| 2 | Copyright (C) 2007, 2009-2020 Free Software Foundation, Inc. |
| 3 | Written by Bruno Haible <bruno@clisp.org>, 2007. |
| 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, or (at your option) |
| 8 | 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 <https://www.gnu.org/licenses/>. */ |
| 17 | |
| 18 | #ifndef _FLOATPLUS_H |
| 19 | #define _FLOATPLUS_H |
| 20 | |
| 21 | #include <float.h> |
| 22 | #include <limits.h> |
| 23 | |
| 24 | /* Number of bits in the mantissa of a floating-point number, including the |
| 25 | "hidden bit". */ |
| 26 | #if FLT_RADIX == 2 |
| 27 | # define FLT_MANT_BIT FLT_MANT_DIG |
| 28 | # define DBL_MANT_BIT DBL_MANT_DIG |
| 29 | # define LDBL_MANT_BIT LDBL_MANT_DIG |
| 30 | #elif FLT_RADIX == 4 |
| 31 | # define FLT_MANT_BIT (FLT_MANT_DIG * 2) |
| 32 | # define DBL_MANT_BIT (DBL_MANT_DIG * 2) |
| 33 | # define LDBL_MANT_BIT (LDBL_MANT_DIG * 2) |
| 34 | #elif FLT_RADIX == 16 |
| 35 | # define FLT_MANT_BIT (FLT_MANT_DIG * 4) |
| 36 | # define DBL_MANT_BIT (DBL_MANT_DIG * 4) |
| 37 | # define LDBL_MANT_BIT (LDBL_MANT_DIG * 4) |
| 38 | #endif |
| 39 | |
| 40 | /* Bit mask that can be used to mask the exponent, as an unsigned number. */ |
| 41 | #define FLT_EXP_MASK ((FLT_MAX_EXP - FLT_MIN_EXP) | 7) |
| 42 | #define DBL_EXP_MASK ((DBL_MAX_EXP - DBL_MIN_EXP) | 7) |
| 43 | #define LDBL_EXP_MASK ((LDBL_MAX_EXP - LDBL_MIN_EXP) | 7) |
| 44 | |
| 45 | /* Number of bits used for the exponent of a floating-point number, including |
| 46 | the exponent's sign. */ |
| 47 | #define FLT_EXP_BIT \ |
| 48 | (FLT_EXP_MASK < 0x100 ? 8 : \ |
| 49 | FLT_EXP_MASK < 0x200 ? 9 : \ |
| 50 | FLT_EXP_MASK < 0x400 ? 10 : \ |
| 51 | FLT_EXP_MASK < 0x800 ? 11 : \ |
| 52 | FLT_EXP_MASK < 0x1000 ? 12 : \ |
| 53 | FLT_EXP_MASK < 0x2000 ? 13 : \ |
| 54 | FLT_EXP_MASK < 0x4000 ? 14 : \ |
| 55 | FLT_EXP_MASK < 0x8000 ? 15 : \ |
| 56 | FLT_EXP_MASK < 0x10000 ? 16 : \ |
| 57 | FLT_EXP_MASK < 0x20000 ? 17 : \ |
| 58 | FLT_EXP_MASK < 0x40000 ? 18 : \ |
| 59 | FLT_EXP_MASK < 0x80000 ? 19 : \ |
| 60 | FLT_EXP_MASK < 0x100000 ? 20 : \ |
| 61 | FLT_EXP_MASK < 0x200000 ? 21 : \ |
| 62 | FLT_EXP_MASK < 0x400000 ? 22 : \ |
| 63 | FLT_EXP_MASK < 0x800000 ? 23 : \ |
| 64 | FLT_EXP_MASK < 0x1000000 ? 24 : \ |
| 65 | FLT_EXP_MASK < 0x2000000 ? 25 : \ |
| 66 | FLT_EXP_MASK < 0x4000000 ? 26 : \ |
| 67 | FLT_EXP_MASK < 0x8000000 ? 27 : \ |
| 68 | FLT_EXP_MASK < 0x10000000 ? 28 : \ |
| 69 | FLT_EXP_MASK < 0x20000000 ? 29 : \ |
| 70 | FLT_EXP_MASK < 0x40000000 ? 30 : \ |
| 71 | FLT_EXP_MASK <= 0x7fffffff ? 31 : \ |
| 72 | 32) |
| 73 | #define DBL_EXP_BIT \ |
| 74 | (DBL_EXP_MASK < 0x100 ? 8 : \ |
| 75 | DBL_EXP_MASK < 0x200 ? 9 : \ |
| 76 | DBL_EXP_MASK < 0x400 ? 10 : \ |
| 77 | DBL_EXP_MASK < 0x800 ? 11 : \ |
| 78 | DBL_EXP_MASK < 0x1000 ? 12 : \ |
| 79 | DBL_EXP_MASK < 0x2000 ? 13 : \ |
| 80 | DBL_EXP_MASK < 0x4000 ? 14 : \ |
| 81 | DBL_EXP_MASK < 0x8000 ? 15 : \ |
| 82 | DBL_EXP_MASK < 0x10000 ? 16 : \ |
| 83 | DBL_EXP_MASK < 0x20000 ? 17 : \ |
| 84 | DBL_EXP_MASK < 0x40000 ? 18 : \ |
| 85 | DBL_EXP_MASK < 0x80000 ? 19 : \ |
| 86 | DBL_EXP_MASK < 0x100000 ? 20 : \ |
| 87 | DBL_EXP_MASK < 0x200000 ? 21 : \ |
| 88 | DBL_EXP_MASK < 0x400000 ? 22 : \ |
| 89 | DBL_EXP_MASK < 0x800000 ? 23 : \ |
| 90 | DBL_EXP_MASK < 0x1000000 ? 24 : \ |
| 91 | DBL_EXP_MASK < 0x2000000 ? 25 : \ |
| 92 | DBL_EXP_MASK < 0x4000000 ? 26 : \ |
| 93 | DBL_EXP_MASK < 0x8000000 ? 27 : \ |
| 94 | DBL_EXP_MASK < 0x10000000 ? 28 : \ |
| 95 | DBL_EXP_MASK < 0x20000000 ? 29 : \ |
| 96 | DBL_EXP_MASK < 0x40000000 ? 30 : \ |
| 97 | DBL_EXP_MASK <= 0x7fffffff ? 31 : \ |
| 98 | 32) |
| 99 | #define LDBL_EXP_BIT \ |
| 100 | (LDBL_EXP_MASK < 0x100 ? 8 : \ |
| 101 | LDBL_EXP_MASK < 0x200 ? 9 : \ |
| 102 | LDBL_EXP_MASK < 0x400 ? 10 : \ |
| 103 | LDBL_EXP_MASK < 0x800 ? 11 : \ |
| 104 | LDBL_EXP_MASK < 0x1000 ? 12 : \ |
| 105 | LDBL_EXP_MASK < 0x2000 ? 13 : \ |
| 106 | LDBL_EXP_MASK < 0x4000 ? 14 : \ |
| 107 | LDBL_EXP_MASK < 0x8000 ? 15 : \ |
| 108 | LDBL_EXP_MASK < 0x10000 ? 16 : \ |
| 109 | LDBL_EXP_MASK < 0x20000 ? 17 : \ |
| 110 | LDBL_EXP_MASK < 0x40000 ? 18 : \ |
| 111 | LDBL_EXP_MASK < 0x80000 ? 19 : \ |
| 112 | LDBL_EXP_MASK < 0x100000 ? 20 : \ |
| 113 | LDBL_EXP_MASK < 0x200000 ? 21 : \ |
| 114 | LDBL_EXP_MASK < 0x400000 ? 22 : \ |
| 115 | LDBL_EXP_MASK < 0x800000 ? 23 : \ |
| 116 | LDBL_EXP_MASK < 0x1000000 ? 24 : \ |
| 117 | LDBL_EXP_MASK < 0x2000000 ? 25 : \ |
| 118 | LDBL_EXP_MASK < 0x4000000 ? 26 : \ |
| 119 | LDBL_EXP_MASK < 0x8000000 ? 27 : \ |
| 120 | LDBL_EXP_MASK < 0x10000000 ? 28 : \ |
| 121 | LDBL_EXP_MASK < 0x20000000 ? 29 : \ |
| 122 | LDBL_EXP_MASK < 0x40000000 ? 30 : \ |
| 123 | LDBL_EXP_MASK <= 0x7fffffff ? 31 : \ |
| 124 | 32) |
| 125 | |
| 126 | /* Number of bits used for a floating-point number: the mantissa (not |
| 127 | counting the "hidden bit", since it may or may not be explicit), the |
| 128 | exponent, and the sign. */ |
| 129 | #define FLT_TOTAL_BIT ((FLT_MANT_BIT - 1) + FLT_EXP_BIT + 1) |
| 130 | #define DBL_TOTAL_BIT ((DBL_MANT_BIT - 1) + DBL_EXP_BIT + 1) |
| 131 | #define LDBL_TOTAL_BIT ((LDBL_MANT_BIT - 1) + LDBL_EXP_BIT + 1) |
| 132 | |
| 133 | /* Number of bytes used for a floating-point number. |
| 134 | This can be smaller than the 'sizeof'. For example, on i386 systems, |
| 135 | 'long double' most often have LDBL_MANT_BIT = 64, LDBL_EXP_BIT = 16, hence |
| 136 | LDBL_TOTAL_BIT = 80 bits, i.e. 10 bytes of consecutive memory, but |
| 137 | sizeof (long double) = 12 or = 16. */ |
| 138 | #define SIZEOF_FLT ((FLT_TOTAL_BIT + CHAR_BIT - 1) / CHAR_BIT) |
| 139 | #define SIZEOF_DBL ((DBL_TOTAL_BIT + CHAR_BIT - 1) / CHAR_BIT) |
| 140 | #define SIZEOF_LDBL ((LDBL_TOTAL_BIT + CHAR_BIT - 1) / CHAR_BIT) |
| 141 | |
| 142 | /* Verify that SIZEOF_FLT <= sizeof (float) etc. */ |
| 143 | typedef int verify_sizeof_flt[SIZEOF_FLT <= sizeof (float) ? 1 : -1]; |
| 144 | typedef int verify_sizeof_dbl[SIZEOF_DBL <= sizeof (double) ? 1 : - 1]; |
| 145 | typedef int verify_sizeof_ldbl[SIZEOF_LDBL <= sizeof (long double) ? 1 : - 1]; |
| 146 | |
| 147 | #endif /* _FLOATPLUS_H */ |