1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
|
/* flonum.h - Floating point package
Copyright 1987, 1990, 1991, 1992, 1994, 1996, 2000
Free Software Foundation, Inc.
This file is part of GAS, the GNU Assembler.
GAS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
GAS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GAS; see the file COPYING. If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
/***********************************************************************\
* *
* Arbitrary-precision floating point arithmetic. *
* *
* *
* Notation: a floating point number is expressed as *
* MANTISSA * (2 ** EXPONENT). *
* *
* If this offends more traditional mathematicians, then *
* please tell me your nomenclature for flonums! *
* *
\***********************************************************************/
#include "bignum.h"
/***********************************************************************\
* *
* Variable precision floating point numbers. *
* *
* Exponent is the place value of the low littlenum. E.g.: *
* If 0: low points to the units littlenum. *
* If 1: low points to the LITTLENUM_RADIX littlenum. *
* If -1: low points to the 1/LITTLENUM_RADIX littlenum. *
* *
\***********************************************************************/
/* JF: A sign value of 0 means we have been asked to assemble NaN
A sign value of 'P' means we've been asked to assemble +Inf
A sign value of 'N' means we've been asked to assemble -Inf
*/
struct FLONUM_STRUCT {
LITTLENUM_TYPE *low; /* low order littlenum of a bignum */
LITTLENUM_TYPE *high; /* high order littlenum of a bignum */
LITTLENUM_TYPE *leader; /* -> 1st non-zero littlenum */
/* If flonum is 0.0, leader==low-1 */
long exponent; /* base LITTLENUM_RADIX */
char sign; /* '+' or '-' */
};
typedef struct FLONUM_STRUCT FLONUM_TYPE;
/***********************************************************************\
* *
* Since we can (& do) meet with exponents like 10^5000, it *
* is silly to make a table of ~ 10,000 entries, one for each *
* power of 10. We keep a table where item [n] is a struct *
* FLONUM_FLOATING_POINT representing 10^(2^n). We then *
* multiply appropriate entries from this table to get any *
* particular power of 10. For the example of 10^5000, a table *
* of just 25 entries suffices: 10^(2^-12)...10^(2^+12). *
* *
\***********************************************************************/
extern const FLONUM_TYPE flonum_positive_powers_of_ten[];
extern const FLONUM_TYPE flonum_negative_powers_of_ten[];
extern const int table_size_of_flonum_powers_of_ten;
/* Flonum_XXX_powers_of_ten[] table has legal indices from 0 to
+ this number inclusive. */
/***********************************************************************\
* *
* Declare worker functions. *
* *
\***********************************************************************/
int atof_generic (char **address_of_string_pointer,
const char *string_of_decimal_marks,
const char *string_of_decimal_exponent_marks,
FLONUM_TYPE * address_of_generic_floating_point_number);
void flonum_copy (FLONUM_TYPE * in, FLONUM_TYPE * out);
void flonum_multip (const FLONUM_TYPE * a, const FLONUM_TYPE * b,
FLONUM_TYPE * product);
/***********************************************************************\
* *
* Declare error codes. *
* *
\***********************************************************************/
#define ERROR_EXPONENT_OVERFLOW (2)
|
