| 1 |
147 |
khays |
/* flonum.h - Floating point package
|
| 2 |
|
|
Copyright 1987, 1990, 1991, 1992, 1994, 1996, 2000, 2003, 2005, 2007
|
| 3 |
|
|
Free Software Foundation, Inc.
|
| 4 |
|
|
|
| 5 |
|
|
This file is part of GAS, the GNU Assembler.
|
| 6 |
|
|
|
| 7 |
|
|
GAS is free software; you can redistribute it and/or modify
|
| 8 |
|
|
it under the terms of the GNU General Public License as published by
|
| 9 |
|
|
the Free Software Foundation; either version 3, or (at your option)
|
| 10 |
|
|
any later version.
|
| 11 |
|
|
|
| 12 |
|
|
GAS is distributed in the hope that it will be useful,
|
| 13 |
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
| 14 |
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
| 15 |
|
|
GNU General Public License for more details.
|
| 16 |
|
|
|
| 17 |
|
|
You should have received a copy of the GNU General Public License
|
| 18 |
|
|
along with GAS; see the file COPYING. If not, write to the Free
|
| 19 |
|
|
Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
|
| 20 |
|
|
02110-1301, USA. */
|
| 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 |
|
|
|
| 35 |
|
|
#include "bignum.h"
|
| 36 |
|
|
|
| 37 |
|
|
/***********************************************************************\
|
| 38 |
|
|
* *
|
| 39 |
|
|
* Variable precision floating point numbers. *
|
| 40 |
|
|
* *
|
| 41 |
|
|
* Exponent is the place value of the low littlenum. E.g.: *
|
| 42 |
|
|
* If 0: low points to the units littlenum. *
|
| 43 |
|
|
* If 1: low points to the LITTLENUM_RADIX littlenum. *
|
| 44 |
|
|
* If -1: low points to the 1/LITTLENUM_RADIX littlenum. *
|
| 45 |
|
|
* *
|
| 46 |
|
|
\***********************************************************************/
|
| 47 |
|
|
|
| 48 |
|
|
/* JF: A sign value of 0 means we have been asked to assemble NaN
|
| 49 |
|
|
A sign value of 'P' means we've been asked to assemble +Inf
|
| 50 |
|
|
A sign value of 'N' means we've been asked to assemble -Inf
|
| 51 |
|
|
*/
|
| 52 |
|
|
struct FLONUM_STRUCT {
|
| 53 |
|
|
LITTLENUM_TYPE *low; /* low order littlenum of a bignum */
|
| 54 |
|
|
LITTLENUM_TYPE *high; /* high order littlenum of a bignum */
|
| 55 |
|
|
LITTLENUM_TYPE *leader; /* -> 1st non-zero littlenum */
|
| 56 |
|
|
/* If flonum is 0.0, leader==low-1 */
|
| 57 |
|
|
long exponent; /* base LITTLENUM_RADIX */
|
| 58 |
|
|
char sign; /* '+' or '-' */
|
| 59 |
|
|
};
|
| 60 |
|
|
|
| 61 |
|
|
typedef struct FLONUM_STRUCT FLONUM_TYPE;
|
| 62 |
|
|
|
| 63 |
|
|
/***********************************************************************\
|
| 64 |
|
|
* *
|
| 65 |
|
|
* Since we can (& do) meet with exponents like 10^5000, it *
|
| 66 |
|
|
* is silly to make a table of ~ 10,000 entries, one for each *
|
| 67 |
|
|
* power of 10. We keep a table where item [n] is a struct *
|
| 68 |
|
|
* FLONUM_FLOATING_POINT representing 10^(2^n). We then *
|
| 69 |
|
|
* multiply appropriate entries from this table to get any *
|
| 70 |
|
|
* particular power of 10. For the example of 10^5000, a table *
|
| 71 |
|
|
* of just 25 entries suffices: 10^(2^-12)...10^(2^+12). *
|
| 72 |
|
|
* *
|
| 73 |
|
|
\***********************************************************************/
|
| 74 |
|
|
|
| 75 |
|
|
extern const FLONUM_TYPE flonum_positive_powers_of_ten[];
|
| 76 |
|
|
extern const FLONUM_TYPE flonum_negative_powers_of_ten[];
|
| 77 |
|
|
extern const int table_size_of_flonum_powers_of_ten;
|
| 78 |
|
|
/* Flonum_XXX_powers_of_ten[] table has legal indices from 0 to
|
| 79 |
|
|
+ this number inclusive. */
|
| 80 |
|
|
|
| 81 |
|
|
/***********************************************************************\
|
| 82 |
|
|
* *
|
| 83 |
|
|
* Declare worker functions. *
|
| 84 |
|
|
* *
|
| 85 |
|
|
\***********************************************************************/
|
| 86 |
|
|
|
| 87 |
|
|
int atof_generic (char **address_of_string_pointer,
|
| 88 |
|
|
const char *string_of_decimal_marks,
|
| 89 |
|
|
const char *string_of_decimal_exponent_marks,
|
| 90 |
|
|
FLONUM_TYPE * address_of_generic_floating_point_number);
|
| 91 |
|
|
|
| 92 |
|
|
void flonum_copy (FLONUM_TYPE * in, FLONUM_TYPE * out);
|
| 93 |
|
|
void flonum_multip (const FLONUM_TYPE * a, const FLONUM_TYPE * b,
|
| 94 |
|
|
FLONUM_TYPE * product);
|
| 95 |
|
|
|
| 96 |
|
|
/***********************************************************************\
|
| 97 |
|
|
* *
|
| 98 |
|
|
* Declare error codes. *
|
| 99 |
|
|
* *
|
| 100 |
|
|
\***********************************************************************/
|
| 101 |
|
|
|
| 102 |
|
|
#define ERROR_EXPONENT_OVERFLOW (2)
|
