112 lines
3.8 KiB
C
112 lines
3.8 KiB
C
|
/* flonum.h - Floating point package
|
||
|
|
Copyright (C) 1987 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 1, 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, 675 Mass Ave, Cambridge, MA 02139, 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! *
|
||
|
|
* *
|
||
|
|
\***********************************************************************/
|
||
|
|
#if !defined(__STDC__) && !defined(const)
|
||
|
|
#define const /* empty */
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#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 int 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. *
|
||
|
|
* *
|
||
|
|
\***********************************************************************/
|
||
|
|
|
||
|
|
void flonum_multip();
|
||
|
|
void flonum_copy();
|
||
|
|
void flonum_print();
|
||
|
|
char * flonum_get(); /* Returns "" or error string. */
|
||
|
|
void flonum_normal();
|
||
|
|
|
||
|
|
int atof_generic();
|
||
|
|
|
||
|
|
|
||
|
|
/***********************************************************************\
|
||
|
|
* *
|
||
|
|
* Declare error codes. *
|
||
|
|
* *
|
||
|
|
\***********************************************************************/
|
||
|
|
|
||
|
|
#define ERROR_EXPONENT_OVERFLOW (2)
|
||
|
|
|
||
|
|
/* end: flonum.h */
|