[binutils.git] / gas / flonum.h

/* flonum.h - Floating point package

   Copyright (C) 1987, 90, 91, 92, 94, 95, 1996 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 PARAMS ((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 PARAMS ((FLONUM_TYPE * in, FLONUM_TYPE * out));
void flonum_multip PARAMS ((const FLONUM_TYPE * a, const FLONUM_TYPE * b,
			    FLONUM_TYPE * product));

/***********************************************************************\
 *									*
 *	Declare error codes.						*
 *									*
 \***********************************************************************/

#define ERROR_EXPONENT_OVERFLOW (2)

/* end of flonum.h */
Commit	Line	Data
252b5132 RH	1	/* flonum.h - Floating point package
	2
	3	Copyright (C) 1987, 90, 91, 92, 94, 95, 1996 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 2, 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, 59 Temple Place - Suite 330, Boston, MA
	20	02111-1307, 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	{
	54	LITTLENUM_TYPE low; / low order littlenum of a bignum */
	55	LITTLENUM_TYPE high; / high order littlenum of a bignum */
	56	LITTLENUM_TYPE leader; / -> 1st non-zero littlenum */
	57	/* If flonum is 0.0, leader==low-1 */
	58	long exponent; /* base LITTLENUM_RADIX */
	59	char sign; /* '+' or '-' */
	60	};
	61
	62	typedef struct FLONUM_STRUCT FLONUM_TYPE;
	63
	64
65	/***********************************************************************\
66	* *
67	* Since we can (& do) meet with exponents like 10^5000, it *
68	* is silly to make a table of ~ 10,000 entries, one for each *
69	* power of 10. We keep a table where item [n] is a struct *
70	* FLONUM_FLOATING_POINT representing 10^(2^n). We then *
71	* multiply appropriate entries from this table to get any *
72	* particular power of 10. For the example of 10^5000, a table *
73	* of just 25 entries suffices: 10^(2^-12)...10^(2^+12). *
74	* *
75	\***********************************************************************/
76
77
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;
81	/* Flonum_XXX_powers_of_ten[] table has */
82	/* legal indices from 0 to */
83	/* + this number inclusive. */
84
85
86
87	/***********************************************************************\
88	* *
89	* Declare worker functions. *
90	* *
91	\***********************************************************************/
92
93	int atof_generic PARAMS ((char **address_of_string_pointer,
94	const char *string_of_decimal_marks,
95	const char *string_of_decimal_exponent_marks,
96	FLONUM_TYPE * address_of_generic_floating_point_number));
97
98	void flonum_copy PARAMS ((FLONUM_TYPE * in, FLONUM_TYPE * out));
99	void flonum_multip PARAMS ((const FLONUM_TYPE * a, const FLONUM_TYPE * b,
100	FLONUM_TYPE * product));
101
102	/***********************************************************************\
103	* *
104	* Declare error codes. *
105	* *
106	\***********************************************************************/
107
108	#define ERROR_EXPONENT_OVERFLOW (2)
109
110	/* end of flonum.h */