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252b5132 | 1 | /* flonum.h - Floating point package |
250d07de | 2 | Copyright (C) 1987-2021 Free Software Foundation, Inc. |
252b5132 RH |
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 | |
ec2655a6 | 8 | the Free Software Foundation; either version 3, or (at your option) |
252b5132 RH |
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 the Free | |
4b4da160 NC |
18 | Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA |
19 | 02110-1301, USA. */ | |
252b5132 RH |
20 | |
21 | /***********************************************************************\ | |
22 | * * | |
23 | * Arbitrary-precision floating point arithmetic. * | |
24 | * * | |
25 | * * | |
26 | * Notation: a floating point number is expressed as * | |
27 | * MANTISSA * (2 ** EXPONENT). * | |
28 | * * | |
29 | * If this offends more traditional mathematicians, then * | |
30 | * please tell me your nomenclature for flonums! * | |
31 | * * | |
32 | \***********************************************************************/ | |
33 | ||
34 | #include "bignum.h" | |
35 | ||
36 | /***********************************************************************\ | |
37 | * * | |
38 | * Variable precision floating point numbers. * | |
39 | * * | |
40 | * Exponent is the place value of the low littlenum. E.g.: * | |
41 | * If 0: low points to the units littlenum. * | |
42 | * If 1: low points to the LITTLENUM_RADIX littlenum. * | |
43 | * If -1: low points to the 1/LITTLENUM_RADIX littlenum. * | |
44 | * * | |
45 | \***********************************************************************/ | |
46 | ||
47 | /* JF: A sign value of 0 means we have been asked to assemble NaN | |
48 | A sign value of 'P' means we've been asked to assemble +Inf | |
49 | A sign value of 'N' means we've been asked to assemble -Inf | |
f0dec3f4 JB |
50 | A sign value of 'Q' means we've been asked to assemble +QNaN |
51 | A sign value of 'q' means we've been asked to assemble -QNaN | |
52 | A sign value of 'S' means we've been asked to assemble +SNaN | |
53 | A sign value of 's' means we've been asked to assemble -SNaN | |
252b5132 | 54 | */ |
b041f888 | 55 | struct FLONUM_STRUCT { |
252b5132 RH |
56 | LITTLENUM_TYPE *low; /* low order littlenum of a bignum */ |
57 | LITTLENUM_TYPE *high; /* high order littlenum of a bignum */ | |
58 | LITTLENUM_TYPE *leader; /* -> 1st non-zero littlenum */ | |
59 | /* If flonum is 0.0, leader==low-1 */ | |
60 | long exponent; /* base LITTLENUM_RADIX */ | |
61 | char sign; /* '+' or '-' */ | |
62 | }; | |
63 | ||
64 | typedef struct FLONUM_STRUCT FLONUM_TYPE; | |
65 | ||
252b5132 RH |
66 | /***********************************************************************\ |
67 | * * | |
68 | * Since we can (& do) meet with exponents like 10^5000, it * | |
69 | * is silly to make a table of ~ 10,000 entries, one for each * | |
70 | * power of 10. We keep a table where item [n] is a struct * | |
71 | * FLONUM_FLOATING_POINT representing 10^(2^n). We then * | |
72 | * multiply appropriate entries from this table to get any * | |
73 | * particular power of 10. For the example of 10^5000, a table * | |
74 | * of just 25 entries suffices: 10^(2^-12)...10^(2^+12). * | |
75 | * * | |
76 | \***********************************************************************/ | |
77 | ||
252b5132 RH |
78 | extern const FLONUM_TYPE flonum_positive_powers_of_ten[]; |
79 | extern const FLONUM_TYPE flonum_negative_powers_of_ten[]; | |
80 | extern const int table_size_of_flonum_powers_of_ten; | |
b041f888 KH |
81 | /* Flonum_XXX_powers_of_ten[] table has legal indices from 0 to |
82 | + this number inclusive. */ | |
252b5132 RH |
83 | |
84 | /***********************************************************************\ | |
85 | * * | |
86 | * Declare worker functions. * | |
87 | * * | |
88 | \***********************************************************************/ | |
89 | ||
dd625418 KH |
90 | int atof_generic (char **address_of_string_pointer, |
91 | const char *string_of_decimal_marks, | |
92 | const char *string_of_decimal_exponent_marks, | |
93 | FLONUM_TYPE * address_of_generic_floating_point_number); | |
94 | ||
95 | void flonum_copy (FLONUM_TYPE * in, FLONUM_TYPE * out); | |
96 | void flonum_multip (const FLONUM_TYPE * a, const FLONUM_TYPE * b, | |
97 | FLONUM_TYPE * product); | |
252b5132 RH |
98 | |
99 | /***********************************************************************\ | |
100 | * * | |
101 | * Declare error codes. * | |
102 | * * | |
103 | \***********************************************************************/ | |
104 | ||
105 | #define ERROR_EXPONENT_OVERFLOW (2) |