/* flonum.h - Floating point package
  Copyright (C) 1987-2024 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 3, 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, 51 Franklin Street - Fifth Floor, Boston, MA
  02110-1301, 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
  A sign value of 'Q' means we've been asked to assemble +QNaN
  A sign value of 'q' means we've been asked to assemble -QNaN
  A sign value of 'S' means we've been asked to assemble +SNaN
  A sign value of 's' means we've been asked to assemble -SNaN
  */
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)

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