/* flonum.h - Floating point package | |

Copyright (C) 1987-2021 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) |