projects / deliverable / binutils-gdb.git / blame
| Commit | Line | Data |
|---|---|---|
| fecd2382 RP |
1 | /* flonum.h - Floating point package |
| 2 | Copyright (C) 1987, 1990, 1991 Free Software Foundation, Inc. | |
| 3 | ||
| 4 | This file is part of GAS, the GNU Assembler. | |
| 5 | ||
| 6 | GAS is free software; you can redistribute it and/or modify | |
| 7 | it under the terms of the GNU General Public License as published by | |
| 8 | the Free Software Foundation; either version 1, or (at your option) | |
| 9 | any later version. | |
| 10 | ||
| 11 | GAS is distributed in the hope that it will be useful, | |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 14 | GNU General Public License for more details. | |
| 15 | ||
| 16 | You should have received a copy of the GNU General Public License | |
| 17 | along with GAS; see the file COPYING. If not, write to | |
| 18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
| 19 | ||
| 20 | /* $Id$ */ | |
| 21 | ||
| 22 | /***********************************************************************\ | |
| 23 | * * | |
| 24 | * Arbitrary-precision floating point arithmetic. * | |
| 25 | * * | |
| 26 | * * | |
| 27 | * Notation: a floating point number is expressed as * | |
| 28 | * MANTISSA * (2 ** EXPONENT). * | |
| 29 | * * | |
| 30 | * If this offends more traditional mathematicians, then * | |
| 31 | * please tell me your nomenclature for flonums! * | |
| 32 | * * | |
| 33 | \***********************************************************************/ | |
| 34 | #if !defined(__STDC__) && !defined(const) | |
| 35 | #define const /* empty */ | |
| 36 | #endif | |
| 37 | ||
| 38 | #include "bignum.h" | |
| 39 | ||
| 40 | /***********************************************************************\ | |
| 41 | * * | |
| 42 | * Variable precision floating point numbers. * | |
| 43 | * * | |
| 44 | * Exponent is the place value of the low littlenum. E.g.: * | |
| 45 | * If 0: low points to the units littlenum. * | |
| 46 | * If 1: low points to the LITTLENUM_RADIX littlenum. * | |
| 47 | * If -1: low points to the 1/LITTLENUM_RADIX littlenum. * | |
| 48 | * * | |
| 49 | \***********************************************************************/ | |
| 50 | ||
| 51 | /* JF: A sign value of 0 means we have been asked to assemble NaN | |
| 52 | A sign value of 'P' means we've been asked to assemble +Inf | |
| 53 | A sign value of 'N' means we've been asked to assemble -Inf | |
| 54 | */ | |
| 55 | struct FLONUM_STRUCT | |
| 56 | { | |
| 57 | LITTLENUM_TYPE * low; /* low order littlenum of a bignum */ | |
| 58 | LITTLENUM_TYPE * high; /* high order littlenum of a bignum */ | |
| 59 | LITTLENUM_TYPE * leader; /* -> 1st non-zero littlenum */ | |
| 60 | /* If flonum is 0.0, leader==low-1 */ | |
| 61 | long exponent; /* base LITTLENUM_RADIX */ | |
| 62 | char sign; /* '+' or '-' */ | |
| 63 | }; | |
| 64 | ||
| 65 | typedef struct FLONUM_STRUCT FLONUM_TYPE; | |
| 66 | ||
| 67 | ||
| 68 | /***********************************************************************\ | |
| 69 | * * | |
| 70 | * Since we can (& do) meet with exponents like 10^5000, it * | |
| 71 | * is silly to make a table of ~ 10,000 entries, one for each * | |
| 72 | * power of 10. We keep a table where item [n] is a struct * | |
| 73 | * FLONUM_FLOATING_POINT representing 10^(2^n). We then * | |
| 74 | * multiply appropriate entries from this table to get any * | |
| 75 | * particular power of 10. For the example of 10^5000, a table * | |
| 76 | * of just 25 entries suffices: 10^(2^-12)...10^(2^+12). * | |
| 77 | * * | |
| 78 | \***********************************************************************/ | |
| 79 | ||
| 80 | ||
| 81 | extern const FLONUM_TYPE flonum_positive_powers_of_ten[]; | |
| 82 | extern const FLONUM_TYPE flonum_negative_powers_of_ten[]; | |
| 83 | extern const int table_size_of_flonum_powers_of_ten; | |
| 84 | /* Flonum_XXX_powers_of_ten[] table has */ | |
| 85 | /* legal indices from 0 to */ | |
| 86 | /* + this number inclusive. */ | |
| 87 | ||
| 88 | ||
| 89 | ||
| 90 | /***********************************************************************\ | |
| 91 | * * | |
| 92 | * Declare worker functions. * | |
| 93 | * * | |
| 94 | \***********************************************************************/ | |
| 95 | ||
| 96 | #ifdef __STDC__ | |
| 97 | ||
| 98 | int atof_generic(char **address_of_string_pointer, | |
| 99 | const char *string_of_decimal_marks, | |
| 100 | const char *string_of_decimal_exponent_marks, | |
| 101 | FLONUM_TYPE *address_of_generic_floating_point_number); | |
| 102 | ||
| 103 | void flonum_copy(FLONUM_TYPE *in, FLONUM_TYPE *out); | |
| 104 | void flonum_multip(const FLONUM_TYPE *a, const FLONUM_TYPE *b, FLONUM_TYPE *product); | |
| 105 | ||
| 106 | #else /* __STDC__ */ | |
| 107 | ||
| 108 | int atof_generic(); | |
| 109 | void flonum_copy(); | |
| 110 | void flonum_multip(); | |
| 111 | ||
| 112 | #endif /* __STDC__ */ | |
| 113 | ||
| 114 | /***********************************************************************\ | |
| 115 | * * | |
| 116 | * Declare error codes. * | |
| 117 | * * | |
| 118 | \***********************************************************************/ | |
| 119 | ||
| 120 | #define ERROR_EXPONENT_OVERFLOW (2) | |
| 121 | ||
| 122 | /* end: flonum.h */ |